Wednesday, April 22, 2009

FANUC AC servo drive system failure repair 30 cases

Abstract: 6.1.2 FANUC AC servo drive system failure repair 30 cases of
Example 231. Job after a few hours of intense vibration fault repair
Fault phenomenon: a used CNC FANUC 0T CNC lathe, normal boot-up of all action, high-speed servo-feed system sports a smooth, low-speed non-crawling, processing of all parts meet the required accuracy. When the machine to work after 5 ~ 7h (time uncertain), Z-axis oscillation radical, CNC alarm, machine tools not work correctly. At this time, even starting off again, as long as the manually or automatically moving Z-axis, in all speed range, there are drastic oscillation. However, if the shutdown time long enough (such as: the second day of boot), machine tools can be a normal job 5 ~ 7h, and again more than failure, so cyclical repetition.
Analysis and treatment process: the machine tool X, Z, respectively, using FANUC 5,10-type AC servo motor drive, spindle drive spindle FANUC 8SAC used machine with Hydraulic Clamp, Hydraulic Tailstock and 15 knives automatic tool changing device, the whole closed protection, auto-Chip. Therefore, the control circuit design more complicated, more powerful machine.
Fault Based on the above phenomenon, starting with a big consideration, analysis of possible causes nothing more than mechanical, electrical two aspects. In the machinery, may be due to the paste of hot plastic deformation of rail, degumming, ball screw, lead screw bearing partial damage or cause improper adjust the non-uniformity of load changes, resulting in feeding system instability. In electrical connection, may be due to changes in the parameters of a component, causing the system to change the dynamic characteristics, resulting in system instability and so on

In view of the machine used is a semi-closed-loop servo system, in order to distinguish the reasons, the first step is to repair loose Z-axis servo motor and ball screw mechanical connection between, in the Z-axis no-load, the running processes to distinguish between mechanical, electrical fault. Found by the test: fault still exists, but failure to extend the time. Therefore, we can confirm the reasons for an electrical fault, and the temperature rise and load size or relevant.
Because of numerical control machine tool servo feed system includes a CNC, servo drives, servo motor, such as the majority of three, in order to further distinguish the reasons, the second step is to repair CNC X-axis and Z-axis to set the speed and position feedback Swaps (CNC's M6 and M8, M7 and M9 swap), namely: the use of the X-axis CNC machine tool commands to control the Z-axis servo and motor sports, CNC Z-axis directions of the X-axis control machine tool servo and motor sport in order to determine fault happened in the CNC or the servo. After the replacement was found, when the Z-axis CNC (with X-axis servo and motor) and normal exercise, but the X-axis (with Z-axis servo and motor) sport when oscillation. Accordingly, the fault can be confirmed in the Z-axis servo drives or servo motor.
Taking into account the machine tool X, Z axis are used in the same series of AC servo drives, the servo PCB board the same type and specifications, in order to further narrow the scope of the inspection, repair of the third step is the second step in the resumption of CNC and X, Z servo the normal inter-connected, will be X, Z of the PCB board after the swap, after adjust settings. After the exchange of discovery, when X-axis is still normal, Z-axis is the same fault.
Based on the above test and inspection, can confirm that the failure was because of Z-axis servo main circuit or servo motor caused by the bad. However, because of X, Z motor specification difference between the larger, on-site without the same type of servo drives and motors available for exchange, it can no longer use the "swap method" for further identification. Taking into account the servo main circuit and servo motor structure is relatively easy, it adopted the principles of analysis to conduct the following inspection, concrete steps are as follows.
1) Analysis of servo main circuit. After the previous inspection, the scope has been narrowed to fault servo main circuit and servo motor, the then editor of the subjective view that the main servo loop, in particular, are a long time because of the inverter power control in high-voltage, high current conditions, the parameters change with temperature more likely to change the value. To this end mapping of the actual AC drive main circuit schematic diagram (as shown in Figure 6-1) (Note: Later, the facts have proven that the author of this step is not right to judge, but in order to accurately reflect the repair process, and reader-friendly system reference, it is still part of the contents of this list).
Figure 6-1 is based on physical mapping of the FANUC AC servo main circuit schematic diagram (plate number: A06B-6050-H103). According to schematic can be analyzed to determine the figure of the role of the various components are as follows:
NFBl into the line circuit breaker for, MCC main contactor for the servo, ZNR into the line for over-voltage suppressors. VA ~ VF to DC rectifier circuit, TA ~ TF for PWM inverter main circuit. C1, C2, C3, R1 for the filter circuit, V1, V.

Abstract: 6.1.2 FANUC AC servo drive system failure repair 30 cases of

Example 231. Job after a few hours of intense vibration fault repair

Fault phenomenon: a used CNC FANUC 0T CNC lathe, normal boot-up of all action, high-speed servo-feed system sports a smooth, low-speed non-crawling, processing of all parts meet the required accuracy. When the machine to work after 5 ~ 7h (time uncertain), Z-axis oscillation radical, CNC alarm, machine tools not work correctly. At this time, even starting off again, as long as the manually or automatically moving Z-axis, in all speed range, there are drastic oscillation. However, if the shutdown time long enough (such as: the second day of boot), machine tools can be a normal job 5 ~ 7h, and again more than failure, so cyclical repetition.

Analysis and treatment process: the machine tool X, Z, respectively, using FANUC 5,10-type AC servo motor drive, spindle drive spindle FANUC 8SAC used machine with Hydraulic Clamp, Hydraulic Tailstock and 15 knives automatic tool changing device, the whole closed protection, auto-Chip. Therefore, the control circuit design more complicated, more powerful machine.
Fault Based on the above phenomenon, starting with a big consideration, analysis of possible causes nothing more than mechanical, electrical two aspects. In the machinery, may be due to the paste of hot plastic deformation of rail, degumming, ball screw, lead screw bearing partial damage or cause improper adjust the non-uniformity of load changes, resulting in feeding system instability. In electrical connection, may be due to changes in the parameters of a component, causing the system to change the dynamic characteristics, resulting in system instability and so on.
In view of the machine used is a semi-closed-loop servo system, in order to distinguish the reasons, the first step is to repair loose Z-axis servo motor and ball screw mechanical connection between, in the Z-axis no-load, the running processes to distinguish between mechanical, electrical fault. Found by the test: fault still exists, but failure to extend the time. Therefore, we can confirm the reasons for an electrical fault, and the temperature rise and load size or relevant.
Because of numerical control machine tool servo feed system includes a CNC, servo drives, servo motor, such as the majority of three, in order to further distinguish the reasons, the second step is to repair CNC X-axis and Z-axis to set the speed and position feedback Swaps (CNC's M6 and M8, M7 and M9 swap), namely: the use of the X-axis CNC machine tool commands to control the Z-axis servo and motor sports, CNC Z-axis directions of the X-axis control machine tool servo and motor sport in order to determine fault happened in the CNC or the servo. After the replacement was found, when the Z-axis CNC (with X-axis servo and motor) and normal exercise, but the X-axis (with Z-axis servo and motor) sport when oscillation. Accordingly, the fault can be confirmed in the Z-axis servo drives or servo motor.
Taking into account the machine tool X, Z axis are used in the same series of AC servo drives, the servo PCB board the same type and specifications, in order to further narrow the scope of the inspection, repair of the third step is the second step in the resumption of CNC and X, Z servo the normal inter-connected, will be X, Z of the PCB board after the swap, after adjust settings. After the exchange of discovery, when X-axis is still normal, Z-axis is the same fault.
Based on the above test and inspection, can confirm that the failure was because of Z-axis servo main circuit or servo motor caused by the bad. However, because of X, Z motor specification difference between the larger, on-site without the same type of servo drives and motors available for exchange, it can no longer use the "swap method" for further identification. Taking into account the servo main circuit and servo motor structure is relatively easy, it adopted the principles of analysis to conduct the following inspection, concrete steps are as follows.
1) Analysis of servo main circuit. After the previous inspection, the scope has been narrowed to fault servo main circuit and servo motor, the then editor of the subjective view that the main servo loop, in particular, are a long time because of the inverter power control in high-voltage, high current conditions, the parameters change with temperature more likely to change the value. To this end mapping of the actual AC drive main circuit schematic diagram (as shown in Figure 6-1) (Note: Later, the facts have proven that the author of this step is not right to judge, but in order to accurately reflect the repair process, and reader-friendly system reference, it is still part of the contents of this list).
Figure 6-1 is based on physical mapping of the FANUC AC servo main circuit schematic diagram (plate number: A06B-6050-H103). According to schematic can be analyzed to determine the figure of the role of the various components are as follows:
NFBl into the line circuit breaker for, MCC main contactor for the servo, ZNR into the line for over-voltage suppressors. VA ~ VF to DC rectifier circuit, TA ~ TF for PWM inverter main circuit. C1, C2, C3, R1 for the filter circuit, V1, V2, R2, T1 for the DC bus voltage control loop. R3 for DC bus current sense resistor, R4, R5 for the servo motor phase current sense resistor, R6 ~ R8 for the servo motor braking resistor energy consumption.
By the static measurement, the above components at boot time and downtime happened after there was no significant change in its parameters, and in the normal range.
For further analysis to determine, in the event of failure, on the main circuit of the practical work carried out by measuring the following analysis:
The DC rectifier circuit, if the VA ~ VF normal, then when the input line voltage Ul for 200V when, A, B between the average DC voltage should read as follows:
UAB = 1.35 × Ul = 270V
Taking into account the role of capacitor C1, the actual average DC bus voltage rectifier voltage should be 1.1 ~ 1.2 times, that is about 300 ~ 325V. Actual measurements (in the actual servo unit for the CN3 and CN4 of 5 feet between the foot of one), this value is normal, you can determine the VA ~ VF without fault.



The main component parameters: C1: 680μF, C2: 1200μF, C3: 3.3μF, R1: 20kΩ
R2: 16Ω R3: 0.12Ω, R4/R5: 0.05Ω, R6/R7/R8: 0.6n
Figure 6-1 servo drive main circuit schematic
For DC bus control circuit, if V1, V2, T1, R2, R3 normal job, then C, D between the DC voltage should be slightly lower than A, B between the voltage, the actual measurement (in the actual servo unit for the CN4 1 feet and 5 feet between the CN4), this value is normal, can be judged more than trouble-free components.
However, TA ~ TF measuring the composition of output PWM inverter main circuit (T1 terminal of 5,6,7), V-phase voltage is sometimes found Tong phenomenon when broken, it should be judged in the V-phase fault.
To further confirm that repair will be U-phase inverter transistor (TA, TB) and V-phase inverter transistor (TC, TD) made a swap, but the phenomenon of the same fault.
After the above checks can confirm: the cause of the malfunction in the servo motor.
2) The servo motor inspection and repair. Confirm the scope of the fault after the servo motor on a careful examination, and ultimately found the V-phase motor insulation resistance in the failure of smaller, when placed after a longer period of time, but also back to normal. To this end, the following steps to repair when opening a servo motor (see Figure 6-2).


Figure 6-2 Schematic diagram of the servo motor

1 - Line socket armature 2 - connecting shaft 3 - Rotor 4 - shell 5 - Winding 6 - rear cover screw connection 7 - to install the installation of Block 1, Block 8 screw connection
9 - encoder fixed screw 10 - encoder connected to screw 11 - back 12 - rubber cap 13 - encoder shaft 14 - encoder cable 15 - encoder socket

① loose screw 6 connected to the rear cover, remove the rear cover 11.
② Remove the rubber cap 12.
③ Remove the encoder connected to screw 10, undocked from the encoder and the connection between motor shaft.
④ screw loose encoder 9, remove the encoder. Note: because of the actual encoder and motor shaft are taper engagement between, connecting to more stringent, check encoder should use specialized tools, carefully removed.
⑤ release screw connection installed Block 8, Block 7, remove the installation.
At this time, can expose the motor windings 5, after examination, found that the motor windings and pinout connections between parts of a long time because of the cooling water leakage, insulation aging; After re-connecting, processing, and then re-installed in accordance with Figure 6-2 installed on Block 7, and a fixed encoder connection screw 10, so that encoder and motor shaft meshing.
3) adjust the rotor position. Upon completion of the repair servo motor, the encoder in order to ensure that the installation is correct, then the rotor position to carry out the inspection and adjustment, as follows:
① the motor armature lines V, W phase (plugs armature B, C foot) connected.
② the U phase (armature A pin plugs) and DC voltage regulator of the "+" Union, V, W and DC voltage regulator of the "-" joint (see Figure 6-3a), encoder add +5 V power supply (encoder plug J, N interpeduncular).
③ through the voltage regulator on the motor armature current excitation add. At this time, because Iu = Iv + Iw, and Iv = Iw, in fact equivalent to the motor in Figure 6-3b as shown in the 90o position, so servo motor (permanent magnet) will be automatically transferred to U-phase position positioning. Note: the excitation current can not add too much, as long as the motor can be targeted to ensure that you (the actual repair, adjust in 3 ~ 5A).
④ At the completion of U-phase motor positioning, the rotary encoder to encoder rotor position detection signals C1, C2, C4, C8 (encoder plug C, P, L, M feet) at the same time as "one" so that the rotor motor position detection signal and the physical location of the same;
⑤ installed encoder fixed screws, fitted with rear cover, complete motor repair.
After more than repair, machine tools restored to normal.


Figure 6-3 Schematic diagram of rotor position adjust
Experience in repair and maintenance of the main points:
CNC machine tools in the repair process, sometimes encountered in some of the more specific fault, such as: Some tools in just machines, systems, and machine working properly, but when the job after a period of time, there will be a failure. Some of this failure to clear through the shutdown, the machine can then re-work; have to go through a longer shutdown time, so that machine, "rest" for some time to re-machine job. Such failure is often referred to as "soft failures."
"Soft failure" repair of CNC machine tool repair is usually the most difficult one to solve the problem. Fault because of the uncertainty and randomness of failures, making good and bad when the machine tool, which give the inspection, measurement caused considerable difficulties. Maintenance personnel must have a higher business level and a wealth of practical experience, a careful analysis of failure phenomena in order to determine the cause of the malfunction, and to solve them.
For a "soft fault" of the repair, when conditions permit, use the "swap method" can quickly determine where the fault, and under the principle of the analysis are the fundamental way to solve the problem. Maintenance personnel should be based on the actual situation, a careful analysis of failure phenomena in order to determine the cause of the malfunction, and to solve them.

Example 232. Small-scale mobile normal, large-scale movement of the fault vibration radical repair

Fault phenomenon: a used CNC FANUC 0T CNC lathes, after boot, as long as the Z-axis mobile one, there intense oscillation, CNC no alarm, machine tools not work correctly.
Analysis and treatment process: After careful observation, inspection, found that the machine's Z axis in a small area (about 2.5mm or less) mobile when working properly, smooth no vibration exercise: But more than once over the scope of machine tools that intense vibration happen.
According to analysis of this phenomenon, the system as well as the position control servo drive itself should be no failure, the preliminary judge in the position detection device failure, that is, the pulse encoder.
Taking into account the machine tool for the semi-closed-loop structure, through the replacement of motor repair carried out to confirm, to determine the cause of the malfunction was due to the negative pulse encoder caused.
To better understand the root causes of failures caused by maintenance when the pilot made the following analysis:
1) in the servo drive off the main circuit, the manually rotate the motor shaft, check the system display is found that the motor is transferred, reverse, the system will be able to display the correct value shows the actual location, indicating the location of encoder A, B, * A, * B signal output correctly.
2) because of the machine Z-axis leadscrew pitch 5mm, so long as the Z-axis movement which happened around 2mm vibration, therefore, the cause of the malfunction may be related to the actual motor position, namely, pulse encoder rotor position detection signals C1, C2, C4 , C8 signal undesirable existence.
Based on the above analysis, taking into account the Z-axis movement can be normal around 2.5mm, which is equivalent to the actual motor rotation 180o, therefore, to further determine the fault location are rotor position detection signal of C8 undesirable existence.
Example in accordance with the same method, remove the pulse encoder, in accordance with encoder connection requests (see Table 6-1), in the pin-N / T, J / K on add DC5V, the rotary encoder shaft, using a multimeter Measurement of C1, C2, C4, C8, found no change in the status of C8 confirmed encoder rotor position detection signal C8 fault exist.

Table 6-1 encoder pin connection table
Pin A B C D E F G H J / K L M N / T P R S
Signal AB C1 * A * BZ * Z shield +5 V C4 C8 0V C2 OH1 OH2

Further inspection found that the internal encoder C8 output driver IC has been damaged; replacement integrated circuit, the re-install the encoder, and the same method of Example adjust rotor angle, the machine back to normal.

Example 233. After boot cyclical vibration alarm repair

Fault phenomenon: Units 1 matching FANUC llM processing centers, boot-up, CRT display No. SV008 alarm, Z-axis vibration cyclical happen.
Analysis and treatment process: FANUC llM alarm system in the SV008 is the meaning of "stop axis error is too large", thus causing the possible reasons for this alarm are:
1) system, position control parameters are set incorrectly.
2) servo system mechanical failure.
3) power supply voltage abnormality.
4) motor and tachometer generator, encoder and other components to connect non-performing.
Based on the above possible causes, combined with the Z axis for a cyclical phenomenon of vibration analysis, and undocked from the motor and lead screw connection test, a preliminary to determine the cause of the malfunction in the electrical servo drive system parts.
In order to further determine the cause of the malfunction, repair replace the X, Z axis servo motor, to test and found the same fault, which determine the cause of the malfunction is not servo motor.
Because of X, Y, Z servo drive control panel specifications, change settings, then the short side, the replacement control panel test to prove that the cause of the malfunction in the driver control panel.
After the replacement of the drive control panel, troubleshooting, machine tools back to normal.

Example 234. Arising in the course of exercise vibration fault repair

Fault phenomenon: Units 1 FANUC 11ME matching system processing center, in the long-term use, X-axis for positive occurs when vibration exercise.
Analysis and treatment process: servo-feed system to produce vibration, crawling main reasons are as follows:
1) mechanical parts of the installation, adjust non-performing.
2) The servo motor or the speed, position detection parts bad.
3) driver settings and adjust improper.
4) external interference, grounding, shielding bad, and so on.
In order to distinguish the fault position, taking into account the machine tool servo system for the semi-closed-loop structure, was torn off and the motor and lead screw connections boot again after testing, found fault still exists, so to determine the initial cause of the malfunction in the electrical servo drive system parts.
In order to further determine the cause of the malfunction, repair replace the X, Y axis servo motor, to test and found that failover to the Y-axis, thus to determine the cause of the malfunction because of X-axis motor are caused by bad.
Oscilloscope measurement of the use of Built-in servo motor encoder signal, and ultimately found that the failure was because of bad encoder caused; replacement encoder, the machine to resume normal work.

Example 235. After the motors have a boot failure screaming repair

Fault phenomenon: Units 1 matching system FANUC 15MA CNC gantry machining center, in the start-up completed after entering the operational state, X-axis as long as the one sport that is high frequency oscillation, motor screaming generated, the system without any warning.
Analysis and treatment process: after the failure to observe the X-axis extension units, the actual extension units found a small vibration displacement; but touch motor output shaft, the rotor can be felt in a very small range, high frequency vibration: vibration and from the noise on the X axis servo motor.
Taking into account the vibration whether it is in motion or stationary when happened, the speed has nothing to do with sports, it can basically rule out the possibility tachogenerator, position feedback encoder, such as the possibility of hardware damage.
Analysis of possible causes are CNC servo drives with the relevant parameter settings, adjust inappropriate: because of machine tool vibration frequency and high time constant smaller current loop more likely to cause vibration.
FANUC 15MA numerical control system because of using digital servo, servo parameters can be adjusted directly through the system, out of repair when the servo page adjust parameters and machine random data provided by the control parameter table and found that the parameters PRMl852, PRMl825 and provide value does not match the settings below:
Parameters of the normal No. practical settings
1852 1000 3414
1825 2000 2770
To re-amend the above-mentioned parameters, the vibration phenomenon of the disappearance of, machine tools to resume normal operation.

Example 236. Ready to drive without the fault signal repair

Fault phenomenon: Units 1 matching system FANUC 0M machining center, machine tools, after starting in the automatic mode to run under, CRT display 401 of the police. Analysis and treatment process: FANUC OM appeared alarm No. 401 is the meaning of "axis servo drive VRDY signal disconnect, that is not ready to drive."
According to the meaning of failure and the machine tool servo feed system actual configuration, maintenance in the following order to carry out an inspection and confirmation:
1) check the L / M / N axis servo drives and found that the status of the drive indicator light PRDY, VRDY not bright.
2) Check the power servo drives ACl00V, ACl8V were normal.
3) Measurement of the drive control board auxiliary control voltage and found that ± 24V, ± 15V abnormal.
Based on the above checks, you can determine the initial failure of the control power driver related.
Double-check the input power and found that X-axis servo-drive input power fuse resistance is greater than 2MΩ, far in excess of the value. After the replacement of the fuse again after measuring DC auxiliary voltage, ± 24V, ± 15V back to normal, the status indicator light PRDY, VRDY have returned to normal, re-run machine tools, the disappearance of 401 alarms.

Example 237. TG servo drive fault alarm repair

Fault phenomenon: a matching system FANUC PM0 CNC lathe, in the processing time to time ALM401 No. recurring alarm.
Analysis and treatment process: FANUC PM0 alarm system ALM401 is the meaning of "Servo Driver's' ready '(DRDY) signal disconnect", drive through the inspection, you can know the reasons are servo drives TG alarm. Because of this failure to happen from time to time, you can consider unreliable cable connection failures are caused by one of the reasons why.
Re-connect the drive cables and shielding lines, grounding line, fault will not recur.

Example 238. Servo drive repair alarm HC

Fault phenomenon: Units 1 CNC FANUC l5MA supporting the gantry machining center, boot connected to one Y-axis servo, the system appeared in over-current alarm (alarm SV003).
Analysis and treatment process: FANUC l5MA alarm system SV003 content "YAXIS EXCESS CURRENT IN SERVO". Check the X, Y, Z servo drives the state of the instructions and found that Y-axis servo drive over-current alarm lights HC (red) light, direction Y Servo drives DC bus over-current existence.
This chapter, we can see from the foregoing, FANUC AC Servo DC bus through the DS will be three-phase bridge rectifier R, S, T three-phase alternating current into a DC rectifier, after filtering capacitor C as the inverter circuit inverter power source. Therefore, the reasons for failure may have:
1) The control panel of DC bus current detection aspect (such as: sampling resistor R1), the adverse feedback aspect.
2) inverse of the power transistor circuit damage.
Through the use of online tester, at the same time Y-axis drive control panel and control panel Z-axis drive signal comparison and found that Y-axis drive control panel has two thick-film integrated circuits (model DV47HA6640) damage, so that the same phase of the two At the same time, high-power transistor turn-on, causing the DC bus short-circuit. Replacement of two damaged after the thick-film integrated circuits DV47HA6640, troubleshooting.

Example 239. α Servo drive alarm "8" Fault repair

Fault phenomenon: the use of FANUC-0M CNC vertical machining center, during processing, there ALM414 alarm, α Servo Driver display alarm "8."
Analysis and treatment process: the machine tool are used FANUCα series digital servo drive system, the control section 5.2.2 of this book, we can see that the meaning of alarm system ALM414 for "X-axis digital servo system error." α drives show "8", said L-axis (in the machine tool for the X-axis) over-current.
Display content according to the police, through the machine self-diagnostic features, diagnosis parameters DGN 720, found its first four as "one", that is, X axis, there were current (HCAL) alarm.
According to Chapter 5 above, FANUC Digital Servo X-axis generated alarm HCAL main reasons are:
1) X-axis servo motor armature line error.
2) Servo Driver internal damage to the transistor module.
3) X-axis servo motor windings internal short circuit.
4) Servo Driver PCB damage to the motherboard.
According to fault conditions, because of the failure of the former machine tool can be a normal job, it can be excluded from the basic X-axis servo motor connected to the possibility of error.
Measurement of X-axis servo motor armature windings and found the same three-phase winding resistance, resistance in the normal range, and would thus be excluded from internal short-circuit the motor windings reasons.
Servo Driver internal inspection of the transistor modules, power supply with multimeter measured input resistance and white only 6Ω, lower than normal. Therefore, we can determine the initial internal drive transistor module damage.
After careful inspection of the transistor module has been damaged; replacement of one transistor module, troubleshooting.

Example 240. Fault phenomenon: FANUC 0i a matching system, αi series servo-driven vertical CNC milling machine, in the automatic processing of sudden ALM414, ALM411 alarm.
Analysis and treatment process: FANUC 0i happen ALM411 alarm system is the meaning of "moving the location of bad times too large"; ALM414 is the meaning of the "digital servo alarm (Z-Axis DETECTION SYSTEM ERROR)".
Check the Z drive show "8", indicating that Z-axis IPM alarm, possible causes are Z-axis over-current, overheating or IPM control voltage is too low. Use of system diagnostic parameters DGN200 examination revealed DGN200 bit5 = "1", show that the Z-axis drive over-current alarm.
Based on the above diagnosis, inspection, can be initially confirmed the cause of the malfunction in the Z-axis over-current. Taking into account the machine tool servo feed system for the semi-closed-loop structure, when the repair was torn off and the motor and lead screw coupling between manually rotating screw, found that the shaft is very difficult exercise, which confirmed the cause of the malfunction in the mechanical parts.
Further examine the mechanical parts of machine tools and found that the surface of non-Z Guide lubricants, machine lubrication system to check the quantitative sub-oil, and to confirm the quantitative sub-Oil undesirable. Replacement of quantitative sub-Oil after a longer period of time through the manual lubrication to ensure good lubrication Z Guide again boot test, the police disappeared, machine to resume normal work.

Example 241. Drive at the same time, OV, TG alarm fault repair

Fault phenomenon: Units 1 matching FANUC 0TE-A2 system CNC Lathe, X-axis movement when alarm ALM401.
Analysis and treatment process: check the alarm when the X-axis servo drive indicator light does not shine PRDY board, OV, TG two alarm indicator light at the same time, CRT display alarm No. ALM401. NC re-start after power outages, according to X-axis positive / negative to the sport button, table sports, but about 2 ~ 3s, there is No. ALM401 alarm, alarm drive unchanged.
Because each boot-up, CRT without warning, and the table can exercise, in general, NC with the servo system should be working properly, fault reasons are many servo system because of overload.
In order to determine the fault position, taking into account the machine tool for the semi-closed-loop structure, when the first repair was torn off and the motor and lead screw between the tooth synchronous belt, check the X-axis mechanical transmission, hand turn round belt and X-axis lead screw, Tool up and down the smooth normal exercise to confirm the normal mechanical transmission system.
Check the servo motor insulation, electrical cables, plugs were normal. But ammeter measuring X-axis servo motor current and found that X-axis static, the current value in the range of 6 ~ 1lA changes. Due to X-axis servo motor for A06B-0512-B205-type motors, the rated current of 6.8A, in normal circumstances, its no-load current can not be greater than 6A, to determine possible causes are motor brake is not released.
Further examine the brake power, brake DC90V input found "0", double-check the fuse block and found the nut loose connection off, resulting in brake should not let go. Reconnect after the brake power supply has been confirmed to join; boot troubleshooting.

Example 242. Drive at the same time, TG, DC alarm fault repair

Fault phenomenon: a second-hand matching FANUC 0M CNC milling machine, using three-axis FANUC S series servo drive one size, boot time, the drive at the same time, L / M / N axis TG, DC alarm.
Analysis and treatment process: FANUC S Series digital servo alarm occurred TG is the meaning of "break the speed control unit, namely, servo motor or encoder connection bad or speed control unit configuration error." DC alarm is the meaning of "over-voltage DC bus," possible causes of the chopper has DC bus tubes, brake resistors, such as non-performing components, or incorrect, such as system power.
Because of machine tools for second-hand equipment, double-check the drive with the line X, Y, Z axis servo motor connection, not found disconnected; check drives main circuit input voltage is correct, the DC bus voltage DC260V, and machine tool X, Y, Z axis has not been working. Based on the above inspection, to determine the basic alarm and the actual external drive unrelated to working conditions, alarm because of the drive itself are the reasons.
Taking into account the machine tool for second-hand equipment, the boot has been a long time ago not to use, the use of observation, drive carefully examined the various components and found that drive fuse FU2 (2A) has been fused; the replacement fuse with the specifications, the re-boot , the drive to eliminate the police, failure to be excluded.

Example 243. Can heat a small amount of exercise and motor fault repair

Fault phenomenon: a second-hand matching FANUC 0M CNC milling machine, using three-axis FANUC S series servo drives one body, after boot, X, Y-axis normal job, but the manual Z-axis movement and found a lesser extent, Z-axis can exercise, but continue to move Z-axis, servo alarm system.
Analysis and treatment process: According to the phenomenon of failure to check the actual work of the machine and found that after the Z-axis can boot a small amount of exercise, a rapid increase in temperature near the surface hot.
Analysis of failures caused by the above reason may be that the machine electrical control system failure or mechanical transmission of non-performing. In order to determine the fault position, taking into account the machine tool are used in semi-closed-loop structure, when the first release of the repair servo motor and lead screw connections, and re-boot test, found the same fault phenomenon, it confirmed that the police are because of the electrical control system caused by bad.
Because Z-axis machine tool servo motor with brake, brake boot after the measurement of input voltage to normal, in the system, the drive off the case, add a separate power supply for brake testing, manual Z-axis rotation and found that brake has been released, hand moving to the motor shaft smooth and easy to prove that a good brake job.
In order to further narrow the fault position, Z-axis servo motor to confirm the work of repair, using the same specifications of the X-axis motor in the machine side of a swap test, found that the motor replaced fever same phenomenon, and work breakdown phenomenon changed, thus excluding the servo motor own reasons.
Drive in order to confirm the work of repair at the drive side of the X, Z-axis drive for the swap test, namely: the X and Z axis drive servo motor connection, Z-axis drive motor connected with the X-axis. Found by the test failover to the X axis, Z axis normal job.
Based on the above tests, can confirm the following points:
1) machine tool mechanical transmission system to normal, a good brake job.
2) CNC system working properly; because when the Z axis with X axis drive motor, the machine without warning.
3) Z-axis servo motor normal job; because it is in the machine side and the X-axis motor swap, the normal job.
4) Z-axis drive working properly: Since the adoption of X drive (no fault) in the lateral exchange of electric counters, control Z-axis motor, the same failure.
Taking all these judgments can confirm that the failure was because of Z-axis servo motor caused by the cable connection.
Servo motor double-check the cable connection and found that the machine at the factory motor armature wire connection error, namely: drive L / M / N terminal is not with the motor plugs A / B / C to connect end-one mapping, phase sequence existence error: reconnect after the fault disappears, Z-axis can be a normal job.

Example 244 ~ 245. Processing overheat alarm fault repair

Example 244. Fault phenomenon: a matching system FANUC 0T MATE CNC lathe, in the processing process, often servo motor overheating alarm.
Analysis and treatment process: the machine tool servo drives are used FANUC S series servo drive, when the alarm when the servo motor touch temperature in the normal range, the actual motor without too familiar phenomenon. Therefore cause failure should be the temperature of servo drive fault detection circuit or overheating Detect bad thermistor.
Shorted through servo motor overheating detection thermistor contact again boot processing tests, by the long-running, fault disappeared, proof motors are overheating because of bad thermistor Detect overheating caused the replacement of components in the absence of conditions, can be temporarily shorted its contact to the system work properly.

Example 245. Fault phenomenon: a matching system FANUC 0T MATE CNC lathe, in the processing process, often X-axis servo motor overheating alarm.
Analysis and treatment process: the process of failure analysis Ibid cases, by checking the appearance of X-axis servo motor temperature too high, overheating in fact exist.
Measurement servo motor no-load current job and found that its value exceeds the normal range. Measurement of the armature winding resistance, discovered partial A relatively short-circuit; disassemble motor examination showed motor protection because of improper processing when coolant into the motor, the motor around the resistance-to-ground short circuit. Repair of electric motors, the machine back to normal.

Example 246. OVC drive failure alarm repair

Fault phenomenon: a matching FANUC 0T-C system, the use of FANUC S series servo-driven CNC lathe, manual sport X-axis, the servo motor does not turn, the system shows ALM414 alarm.
Analysis and treatment process: FANUC 0T-C appears ALM 414 alarm is the meaning of "X-axis digital servo alarm", by examining the system diagnostic parameters DGN720 ~ 723, found one of DGN720 bit5 = l, it can determine the cause of the malfunction of the machine tools are X-axis OVC (over-current) report to the police.
Analysis resulted in a lot of failure, but the most common repair servo motor brakes are not loose.
In this machine, because of the use of oblique bed layout, so the X-axis servo motor with a brake to prevent the decline in the blackout. After inspection, the machine failure is not brake release: Based on schematic diagram and system diagnostic signals in the state of analysis, the failure was because of bad contact between the relay caused by the replacement of the relay after the machine back to normal.

Example 247-Example 248. Parameter setting error caused by fault repair

Example 247. Fault phenomenon: FANUC 0TD a matching system of second-hand CNC lathe, FANUC matching sub-α Series Digital Servo, after boot, the system shows ALM417, 427 alarm.
Analysis and treatment process: FANUC 0TD appear ALM 417,427 alarm is the meaning of the "digital servo parameters are set incorrectly."
Because of machine tools for second-hand equipment, system debugging and found the battery has been lost, therefore, the system's parameters are to varying degrees, there is an error. Further inspection system motherboards, found on the motherboard alarm indicator light L1, L2-liang, the drive displays "-", indicating that the drive is not ready.
According to the system alarm ALM417, 427 can confirm that the alarm caused by the possible reasons are:
1) motor model parameters 8 * 20 are set incorrectly.
2) the shifting parameters of the motor 8 * 22 are set incorrectly.
3) the speed of the feedback pulse parameters 8 * 23 are set incorrectly.
4) position feedback pulse parameters 8 * 24 are set incorrectly.
5) resolution of position feedback pulses PRM037bit7 set an error, and so on.
Through the Digital Servo Settings page, in the correct parameters set above, as well as system PRM900 ~ PRM919 parameters, through digital servo initialization operation, the police disappear, the alarm indicator light on the motherboard L1, L2 out, the drive shows "0" , indicating that the drive is ready, the troubleshooting.

Example 248. Fault phenomenon: Units 1 FANUC 0TD matching αC servo drive system of second-hand CNC lathe, after booting the system shows ALM401 alarm.
Analysis and treatment process: FANUC 0TD system is due to report to the police ALM401 drive not ready, (DRDY) signal is not connected.
Check the drive status and found that 7 digital tube display as "1", meaning that the drive is not ready. Because of machine tools for second-hand equipment, downtime has been long, and after changing hands many times, therefore, the possibility of loss of system parameters larger.
Maintenance, by examining the use of electrical machine models, encoder type, screw pitch and the reduction ratio and other related parameters, the re-digital servo system initialization processing (initialization method see Chapter 5, paragraph section 5.2.6), the start-up machine, the drive shows "0", CNC alarm disappeared, through the operation of testing, machine tool X, Z axis can be a normal job.

Example 249-Example 250. Workpiece size appears erratic changes in the fault repair

Example 249. Fault phenomenon: a matching FANUCPM0 CNC lathes, in the course of their work and found that X-workpiece size appears to irregular changes.
Analysis and treatment process: CNC machine tool processing size instability usually associated with the installation of mechanical transmission system, connecting with accuracy, as well as servo feed system settings associated with the adjustment. In the machine tool using the dial indicator carefully measuring X-axis positioning accuracy and found that moving a pitch of each screw, X to the actual size is always to increase the scores of microns, and continue to accumulate this error.
Based on the above analysis of the phenomenon, the cause of the malfunction and the system seems to "gear ratio", a reference counter capacity, the number of encoder pulse parameters such as set, but after inspection, the above parameter settings are correct, rule out the improper parameter settings cause failure.
In order to further determine the fault location, repair removed when X-axis servo motor and the motor shaft through the dash mark, using manual feed incremental move in X axis, examination revealed that X-axis for each incremental movement of a pitch when the motor shaft rotation are greater than 360o.
At the same time, more than found during Detected per servo motor rotation to a fixed point of view when the "snap back" phenomenon, and in the absence of "snap back" regional, sports and motor shaft turned away from the point of view of the basic line (not exact measurements, to rely on observation to determine).
Based on the above test can determine the fault is due to X-axis position detection system caused by non-performing, taking into account the "snap back" only produce a fixed point of view, and in the absence of "snap back" regional, sports and motor shaft turned away from the the perspective of the basic line. Therefore, we can further confirm the fault and the measurement system cable connection, the system interface circuit has nothing to do, the reasons are bad encoder itself.
Through the replacement of encoder test, to confirm because of the failure was caused by bad encoder to replace the encoder, the machine back to normal.

Example 250. Fault phenomenon: a matching system FANUC 0T CNC lathe, in the job operation, the processing parts of the Z-axis size became smaller, and each change of cutting force and machine tool-related, when the cutting force increases, changes in the volume of will also become larger.
Analysis and treatment process: According to analysis of failure phenomena, resulting in failure in servo motor and ball screw mechanical connection between the. Because of the machine tool used are directly connected to the coupling structure of the form, when the servo motor and ball screw flexible coupling between the failure to lock, the screw and the motor will have a relative slip between, resulting in Z-axis Feed size became smaller.
Can not solve the coupling method of locking the normal cone sets are pressed to increase the friction. If the coupling with the screw, between the motor with the poor to rely on the coupling itself can not guarantee that the locking screw locking, the usual solution is to group sets of cone-shaped flexible in an open one of about a 0.5mm the slit to increase flexibility in sets of cone-shaped volume contraction, so that can be solved with the screw coupling, between the tie in with the bad motor caused by loosening.

Example 251. Actual mobile volume does not match with the theoretical value of the fault repair

Fault phenomenon: a package of CNC Lathe FANUC 0T, the user during processing and found that X, Z axis movement of the actual size does not match with the theoretical value.
Analysis and treatment process: because of the machine tool X, Z-axis normal job, failure is only the movement of the actual value does not match with the theoretical value, it can determine the machine tool system, the drive components, such as no fault, the cause of the problem is caused by mechanical transmission system parameters and control system parameters to match misconduct.
Mechanical drive system and control system to match the parameters in different systems vary, usually have electronic gear ratio, instructions multiplying factor, multiplying Detect coefficient, encoder pulses, such as screw pitch. The above parameters must be set in order to guarantee the system's instructions and the actual value of the mobile value.
In this machine, the system settings by examining the parameters of discovery, X, Z-axis servo motor encoder pulse number of system settings inconsistent. In the machine, X, Z axis motor model, but the contents were encoder pulses per revolution of 2000 and 2500 pulses, and the system settings just the opposite of that.
It is understood that the cause of the malfunction during the machine tool users are overhaul, the once removed X, Z-axis servo motor to clean up, but the installation did not notice the difference between encoders, thus giving rise to the above questions. On X, Z motor exchange, the machine to resume normal work.

Example 252. FANUC 0TD alarm system repair ALM416

Fault phenomenon: Units 1 FANUC 0TD matching αC servo drive system of second-hand CNC lathe, after booting the system shows ALM401, ALM416 alarm.
Analysis and treatment process: FANUC 0TD alarm system ALM401 with the meaning of the foregoing, ALM416 alarm is the meaning of "non-performing position measurement system."
Inspection system diagnostic parameters, DGN202 bit4 = l, to prove the cause of the malfunction are motor Built-in serial pulse encoder disconnected.
According to the police prompted to check X, Z-axis encoder connecting cable and found that X-axis position encoder cable disconnected part of existence.
Re-connect, the replacement of encoder cable, the police ruled out, machine X, Z-axis normal job.

Example 253. SV023 happen FANUCll alarm system repair

Fault phenomenon: Units 1 FANUC llM system supporting the processing center, the boot when the alarm happened SV023 and SV009.
Analysis and treatment process: FANUC llM happen SV023 is the meaning of alarm "Servo drive system overload", SV009 is the meaning of alarm "in the mobile process, the position error to follow the ultra-poor." In these two alarms, such as happened SV023 driver alarm, it will surely give rise to stop drives, resulting in alarm SV009. Therefore, SV023 is the main reason for the machine tool failure. SV023 generated alarm possible reasons are:
1) motor load too.
2) speed control unit on the hot relay action.
3) transformer thermal servo switch action.
4) drive renewable energy excessive feedback.
5) speed control unit adjust the settings wrong or improper.
For the above fault, you can check the adoption of the following methods, identify:
1) motor load too: in the machine run-time, by measuring the electrical current, to determine whether it is over rated.
2) speed control unit on the hot relay actions: can be hot by checking the current relay settings is less than motor rated current, and to observe the hot action to determine whether the relay.
3) transformer thermal servo switch actions: touching the transformer can be carried out to determine the surface temperature. Transformer such as the surface temperature is below 60oC, the thermal switch action, then this switch bad; otherwise, belong to the overheated transformer.
4) renewable sources of feedback can be excessive: You can check the motor increases, minus the frequency is too high: vertical axis, such as the balance is appropriate.
5) speed control unit adjust the settings wrong or improper: You can set the client by checking the signal waveform, such as dynamic to confirm.
Based on the above analysis, the tested machine motor when transported by air currents and found that the current value has exceeded the motor rated current. Servo motor will be removed after the non-electric motor, the hand rotation motor output shaft and found that the rotation axis difficult. Because of the motor without brake, therefore, can determine the motor exist problem, after further inspection found that the motor output shaft bearings damaged machine back to normal after the repair.

Example 254. FANUC l5 occasional SV013 alarm system maintenance

Fault phenomenon: Units 1 matching system FANUC 15MA CNC gantry machining center, in the normal process, the system SV013 occasional alarm.
Analysis and treatment process: FANUC 15MA system alarm SV013 is the meaning of "Y-axis servo-drive V-READY signal disconnected (YAXIS IMPROPER V-READY OFF)". Check the servo drive and found that Y-axis servo drive VRDY on the light-emitting diode does not shine.
Because FANUC AC servo-driven VRDY signal in the servo drives are the main contactor pull-MCC, servo drives connected to the main loop, the job such as a normal drive (ie drive without over-current, over-voltage, overheating, gun alarm feedback) , MCC to maintain pull-in, signal VRDY as "1."
The substance of this failure are the main contactor normal pull-MCC failed to maintain contact or poor contact, the foregoing in accordance with this chapter, and its possible causes are:
1) Servo drive failure.
2) drive back to passing the main current.
3) CNC and servo unit of the cable connection between the non-performing.
Double-check the Y-axis servo drive, found drivers VRDY In addition to light-emitting diode does not shine, no other warning lights, which can be excluded from the initial drive current passing through the main reason for return. Check the CNC and servo drives connected between the cable and found no connection problems.
In order to further determine the cause of the malfunction, repair will be Y-axis and Z axis servo drive control panel to carry out the exchange, but the fault still exists, the drive control panel ruled out the reasons for non-performing. Then, they exchanged Y-axis and Z axis servo drive amplifier board, the exchange after the failure from the Y-axis to the Z axis, thus to determine the cause of the malfunction in the Y-axis servo drive amplifier board.
FANUC AC servo control circuit to conduct a detailed inspection, confirmed the main circuit of electrical components had no failures, the resulting inference may have problems MCC contactors are undesirable in itself. In order to confirm, through an external power supply when repair directly to the MCC contactor coil 110V AC control voltage increases, the pilot found that MCC automatically disconnected phenomena exist that MCC contactor coil failures exist.
Replacement of contactors, the machine back to normal.

Example 255. FANUC l6 system ALM411, ALM414 alarm repair

Fault phenomenon: a matching system FANUC l6 import Horizontal Machining Center, in the B-axis rotation when ALM414, ALM411 alarm.
Analysis and treatment process: FANUC 16 happened ALM411 alarm system is the meaning of "moving the location of bad times too large"; ALM414 is the meaning of the "digital servo alarm (B-Axis DETECTION SYSTEM ERROR)".
The B-axis machine tool rotary table, after the diagnosis, inspection, confirmed the cause of the malfunction for the B-axis over-current.
Carefully observe the B-axis machine tool fault phenomenon and found that B-axis in a lift after the beginning of rotation, the two movements almost no pause between the process, therefore, analyze the cause of the malfunction may be due to the B-axis is not in place caused by lifting.
Given the machine hydraulic system pressure has reached the specified value, and B-axis lift switch adjust the installation location is not convenient, through the PMC procedure examination found that the signal is lifted PMC process of implementation through the delay. To this end, first of all by extending the delay time, carried out further tests.
Through the test, concluded that when the delay time after the lengthening, B-axis can be completely lifted the state of arrival, combined with the efficiency and reliability of the factors to consider, and ultimately will be changed to 1s delay after the original 0.5s, troubleshooting, machine tools back to normal .

Example 256. FANUC 16 alarm system repair ALM410

Fault phenomenon: Units 1 matching system FANUC l6 Horizontal Machining Center, CNC Department appears after boot ALM410 (Z axis) report to the police, not the normal start-up machine.
Analysis and treatment process: FANUC 16 system ALM410 is the meaning of "stop the arbitrary axis to follow the error tolerance." Cause the system to which the more reason for alarm, such as motor electrode phase sequence is incorrect, bad connections, such as encoder.
In this machine, because of failure before the machine working properly, it can basically rule out the causes of motor phase sequence to check the drive and motor connections are correct, plug fixed well, ruled out the connection may have reason for alarm.
Further observation of the actual machine tool fault phenomenon and found that when the machine boot without alarm, but once the Y-axis brake release, the spindle box that has more obvious whereabouts immediately appear CNC alarm. In view of the above phenomena, when the repair under the Y-axis machine tools are used in the hydraulic system is characterized by balance, combined with Y-axis spindle box in existence since the drop after the release of the phenomenon, a preliminary judge, alarm system and the hydraulic balance.
In order to verify, in the lower part of spindle box of wood with local support, and a small amount of space left after the start-up hydraulic system, and manually release the Y brake after a mandatory trial found that once the Y brake was loosened, the spindle box immediately the whereabouts and location Get support.
However, in the Y-axis has been supported by circumstances, the re-start machine, the system without warning, Y-axis can also be a normal job, which confirmed that the failure was because of Y-axis caused by an adverse balance system. Hydraulic balance of system maintenance, adjustment, the fault disappears, machine tools resume normal job.

Example 257. FANUC l6B alarm system repair ALM414

Fault phenomenon: Units 1 matching system FANUC l6B, α Series Servo-driven horizontal machining center in users drives damaged, re-replacement of Y-axis drive, the boot after moving Y-axis when ALM414 alarm.
Analysis and treatment process: FANUC l6B appear ALM414 alarm is the meaning of the "digital servo alarm," the cause of the malfunction diagnosis of the parameters can DGN200 ~ DGN204 be checked.
Inspection found that the machine DGN200 bit2 = "1", indicates that the existence of non-performing regenerative braking circuit, and further checks the drive, its status appears as "4",? Show that the regenerative braking circuit alarm exist.
Taking into account the replacement drive is a brand-new spare parts, according to the scene learned that the replacement drive has been confirmed before the Y-axis motor, connect the cable there was no anomaly, the above analysis, a preliminary to determine the cause of the malfunction drives are caused by incorrect settings.
By examining the actual machine tool control system electrical design, confirm that the axis of the external drive to use the regenerative braking resistor 200W. Therefore, the driver must set the corresponding. Drive to open the front cover to check and found that the regenerative braking drive settings (S3/S4) is incorrect. After the correct settings, troubleshooting, machine tools to resume normal work.

Example 258-Example 259. FANUC l6B system ALM414, ALM411 alarm repair

Example 258. Fault phenomenon: Units 1 matching system FANUC 16B, α servo-driven vertical machining center imports, in the automatic processing process, often Y-axis ALM414, ALM411 alarm.
Analysis and treatment process: FANUC l6B system ALM414, ALM411 meaning and analysis of the process with the foregoing, through the diagnostic parameters DGN200, DGN201 inspection, appear when the alarm DGN200 bit7 = "1", DGN201 bit7 = "0", indicates that the cause of the malfunction for the Y axis motor overheating. Hand in the failure of Y-axis servo motor, sensory motor looks hot, in fact proved the existence of Y-axis motor overheating.
Because of machine tools in the boot of a certain period of time after the job properly, without warning, therefore, the initial Y-axis to determine the failure was caused by too much load.
After the shutdown, manually rotating Y-axis lead screw and found that very difficult to rotate, which confirmed the cause of the malfunction in the mechanical parts. Check repair Y-axis rail extension units and found that the machine tool bed onto chip stacking, Y-axis guideways pollution. Re-clear the iron, removed Y-axis guideways Article inlaid on the extension unit to conduct a comprehensive clean-up, maintenance, after continuous operation test, fault disappear machine to resume normal work.

Example 259. Fault phenomenon: Units 1 matching system FANUC 16B, α servo-driven vertical machining center imports, in the rotary table (A axis) rotation, the emergence of A-axis ALM414, ALM411 alarm.
Analysis and treatment process: FANUC l6B system ALM414, ALM411 meaning and analysis of the process with the foregoing, through the diagnostic parameters of inspection confirmed that the cause of the malfunction is the A-axis overload. Scene analysis, the A-axis machine tools for the rotary table, and have brought Tailstock Hydraulic fixture, causing A-axis may be caused by overload and the turret with the release of the release Tailstock relevant action. In order to determine the fault position, in the repair process, remove the hydraulic clamp, so that Tailstock turret connection was torn off and then boot test machine fault disappears, thus determining, leading to A-axis may be caused by overload and Tailstock relevant. Boot, after the release Tailstock, manual rotation rotation Tailstock found difficult to re-adjust Tailstock clamp, loose bodies, in the confirmation Tailstock reliable release, the boot test, fault disappears, machine tools back to normal.

Example 260. FANUC l6B occasional ALM414 alarm system maintenance

Fault phenomenon: Units 1 matching system FANUC l6B, α servo-driven vertical machining center imports, in the automatic processing machine, the occasional ALM414 (X Digital Servo) alarm, after rebooting machine failures can disappear.
Analysis and treatment process: FANUC 16B alarm system ALM411 meaning with the foregoing, through the diagnostic parameters confirmed that the cause of the malfunction are X-axis encoder connection bad. Because of occasional failure to analyze the possible reasons are the largest X-axis encoder connection bad.
Through the X-axis servo motor encoder checks and found that their plugs loose, re-fixed, troubleshooting, machine tools to resume normal work.




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    Replies
    1. This post has really help me to understand importance of Test And Tag Electrical Equipment You really did include a lot of helpful details. I truly enjoyed this post.

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  2. i need parameter for spindle stop immediate to read the M5 in auto cycle

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  3. I love reading through your blog, I wanted to leave a little comment to support you and wish you a good continuation. Wishing you the best of luck for all your blogging efforts.

    Electrical Test and Tag

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  4. Hello,

    Nice article has been shared here. thanks for sharing this post here. i really enjoyed reading your this post and did get lots of good points from here. it would be nice if you can share some information related to free cad software here in your future posts....

    Thanks,

    ReplyDelete
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  6. I feel pretty happy to have discovered your webpages and look forward to tons of more pleasurable times reading here. Thanks a lot once again for a lot of things.

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  7. Do you have scematics, I work in cnc repairing too. Carlos Cabrera

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  8. Excellent post! I must thank you for this informative read. I hope you will post again soon.
    Kind regard
    PLC Repairs

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