Troubleshooting - Mitsubishi Electric FR-A800 Series Beginner's Manual

Troubleshooting

7.1 Troubleshooting
When an error occurs or you experience some other problem with operation you can often diagnose
the cause from the behaviour of the motor and/or the inverter.
Error
Motor does not rotate
as commanded.
Motor rotates in oppo-
site direction
Speed greatly differs
from the setting
Acceleration/decelera-
tion is not smooth
Motor current is large
Speed does not increase
7 - 2
Possible cause Check points / Remedy
Are the terminals R/L1, S/L2 and T/L3) connected properly?
Is the proper power supply voltage applied?
Main circuit or motor
are not connected prop-
Are the terminals U, V and W wired properly?
erly.
Check that the jumper across P1 and P/+ is connected.
Check that the start signal is input.
Check that both the forward and reverse rotation start signals are not
input simultaneously.
Check that the frequency setting signal is not zero.
Missing or wrong input
signals
Check that the AU signal is on when the frequency setting signal is 4
to 20mA.
Check that the output stop signal (MRS) or reset signal (RES) is not on.
Check that the sink or source jumper connector is fitted securely.
Check that the setting of Pr. 79 is correct.
Incorrect parameter set-
Check that frequency settings of each running frequency (such as
tings
multi-speed operation or Pr. 1) are not zero.
Check that the load is not too heavy.
Load
Check that the shaft is not locked.
Other Is a error message displayed (e. g. E.OC1)?
Check that the phase sequence of output terminals U, V and W is cor-
Wrong phase sequence
rect.
Start signal
Check that the start signals (forward rotation, reverse rotation) are
connected properly.
Incorrect rotation signal
Frequency setting sig- Check that the frequency setting signal is correct. (Measure the input
nal signal level.)
Incorrect parameter set-
Check the setting of the parameters 1, 2, and 19.
tings
Check that the input signal lines are not affected by external noise.
External noise
(Use shielded cables)
Load Check that the load is not too heavy.
Incorrect settings for
Check that the acceleration and deceleration time settings are not too
acceleration/decelera-
short (Pr. 7 and 8). Increase this values.
tion time
Load Check that the load is not too heavy.
Check that the torque boost setting is not too large to activate the
Torque boost
stall function.
Load Check that the load is not too heavy.
Torque boost Check that the Pr. 0 „Torque boost" setting is appropriate.
Maximum frequency Check that the maximum frequency (Pr. 1) setting is correct.
Load Check that the load is not too heavy.
Check that the torque boost setting is not too large to activate the
Torque boost
stall function.
Protective and diagnostics functions