4.7 Setup Troubleshooting and Possible Solutions
♦ Riding Comfort Related Problems
The following table describes the most common problems related to ride comfort and proposes countermeasures to those
problems. Before taking any action, make sure the startup procedures have been performed as previously described.
Problem
Control Mode and Possible Cause
Corrective Action
V /f and OLV
Insufficient torque when the brake is released.
• Increase the DC Injection Braking Current at Start using parameter S1-02.
• Increase the Minimum Output Frequency Voltage (E1-10) and Medium
Output Frequency Voltage (E 1-08) V /f pattern voltages. Make sure, that the
starting and leveling current does not rise too high.
DC Injection and brake timing is not optimized.
Set the time for DC Inj ection Braking at Start (S1 -04) as short as possible, and
make sure that brake releases com pletely before the motor starts to turn.
OLV
The slip or torque compensation function acts too slow ly.
• D ecrease the Torque Compensation Time (C4-02).
• D ecrease the Slip Compensation Time (C3-02).
Rollback at start
The speed control is not responding fast enough when the
brake is released.
Adjust the speed control loop parameters used During Position Lock. Increase
C5-19 and reduce C5-20.
CLV
CLV/PM
The Position Lock control loop does not respond fast enough.
• Adjust the speed control loop parameters used During Position Lock.
Increase C5-19 and reduce C5-20.
• Increase the Position Lock Gain at Start 1 in S3-01 gradually. If vibration
occurs reduce it.
• Increase the Position Lock Gain at Start 2 in S3-02 gradually until rollback
disappears.
A ll
Motor torque is not fully established when the brake is
released.
Lengthen the Brake R elease D elay Time (S1-06) and the tim e for DC
Injection Braking / Position Lock at Start (S1-04).
Motor contactor closes too late.
Make sure that the contactors are closed before the U p/Dow n command is
issued.
Motor starts turning when the brake is not com pletely released
or runs against the brake.
Increase the DC Injection Braking Time at Start using parameter S1-04.
Shock at start
A ll
Acceleration rate is changing too quickly.
D ecrease the Jerk at Start. D ecrease C2-01 i f set in m /s2, increase C2-01 if set
in s.
Rollback occurs during brake release.
Refer to “Rollback at start”.
A ll
Brake is applied too early, causing the motor to run against the
brake.
Increase the D elay Time to Close the Brake (S1-07). If necessary, also
increase the DC Injection Braking Time at Stop S1-05.
Motor contactor is released before the brake is fully applied.
Check the motor contactor sequence.
Shock at stop
CLV
CLV/PM
Rollback occurs before the brake applies at stop.
• Make sure the speed control loop parameters for position lock are adjusted
properly (C5-13 and C5-14).
• Increase the Position Lock Gain at Stop S3-03 gradually until no rollback
occurs. If vibration occurs reduce the gain S3-03.
OLV
Too fast torque or slip compensation.
• Increase the Torque Compensation D elay Time (C4-02).
• Increase the Slip Compensation Delay Time (C3-02).
Jerk occurs due to overshoot
when the motor reaches top
speed.
Speed control loop setting is too soft or too hard.
• Adjust the Speed Control Loop Gain C5-01 and Integral Time C5-02.
• Adjust Inertia Compensation parameters ( n 5 -D D ) if speed control loop
settings can not solve the problem
CLV
CLV/PM
Incorrect motor data.
• For induction motors readjust the motor data (Е 2 -П П ), especially the slip
(E 2-02) and no-load current values (E2-03), or perform Auto-Tuning again.
• For PM motors readjust the motor data in Е 5 -П П or perform Auto-Tuning.
Inertia compensation function is not set up correctly.
If the Inertia Compensation Function is used (n5-01=1) make sure the values
in n5-02 and n5-03 are correct.
A ll
The acceleration rate changes too quickly when reaching the
selected speed.
Decrease the Jerk at the End o f Acceleration. D ecrease C2-02 i f set in m /s2,
increase C2-02 i f set in s.
V /f and OLV
N ot enough torque at low speed.
Increase the M inimum and M iddle Voltage L evels for the V /f pattern voltage
(E1-10 and E1-08 respectively). M ake sure that the Starting and Leveling
Current does not rise too high.
OLV and
Motor data incorrect.
Adjust the motor data (Е 2 -П П ), especially the motor slip (E 2-02) and no-
CLV
Too much slip compensation.
load current values (E2-03), or perform Auto-Tuning.
Motor stops shortly (under
shoot) when the leveling
speed is reached.
CLV
CLV/PM
Speed control loop responds too slow.
Increase the Speed Control Gain and reduce the Speed Control Integral Time
used for L ow Speed at Stop. The parameters to be changed depend on the set
ting o f C 5-05 and whether a third set o f speed loop settings is used. Refer to
S p e ed L o o p A d ju stm en ts (C L V a n d CLV /PM ) on p a g e 113.
The inertia compensation function is not set up correctly.
If the Inertia Compensation Function is used (n5-01 = 1) make sure the values
in n5-02 and n5-03 are correct.
A ll
The deceleration rate changes too quickly when reaching
leveling speed.
Decrease the Jerk at the End o f Deceleration. D ecrease C2-04 if set in m /s2,
increase C 2-04 i f set in s.
Motor speed overshoot at
acceleration end and under
shoot w hen reaching leveling
speed occurs. Problem can
not be resolved by adjusting
the speed loop.
CLV
CLV/PM
Inertia is high.
U se the Inertia Compensation Function. Set n5-01 to 1 and then adjust param
eters n5-02 and n5-03 as described in Inertia C om pensation (C L V a n d C L V /
PM ) on p a g e 114.
Motor or machine vibrates at
high speed or top speed
OLV
Torque compensation responds too quickly.
Increase the Torque Compensation D elay Time (C4-02).
CLV
CLV/PM
Speed control loop adjusted too hard.
D ecrease C5-01, then increase C5-02.
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YASKAWA ELECTRIC SIEP C710616 33D YASKAWA AC Drive L1000A Technical Manual