Faults And Check Points - Mitsubishi Electric FR-A520-0.4K-NA Instruction Manual

5.2.2 Faults and check points

POINT: Check the corresponding areas. If the cause is still unknown, it is recommended to initialize the
parameters (return to factory settings), re-set the required parameter values, and check again.
( 1 ) Motor remains stopped.
1) Check the main circuit
·
Check that a proper power supply voltage is applied (operation panel display is provided).
·
Check that the motor is connected properly.
2) Check the input signals
·
Check that the start signal is input.
·
Check that both the forward and reverse rotation start signals are not input.
·
Check that the frequency setting signal is not zero.
·
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 CS signal is not off when automatic restart after instantaneous power failure is
selected (Pr. 57 = other than "9999").
3) Check the parameter settings
·
Check that the reverse rotation prevention (Pr. 78) is not selected.
·
Check that the operation mode (Pr. 79) setting is correct.
·
Check that the bias and gain (Pr. 902 to Pr. 905) settings are correct.
·
Check that the starting frequency (Pr. 13) setting is not greater than the running frequency.
·
Check that various operational functions (such as three-speed operation), especially the maximum
frequency (Pr. 1), are not zero.
4) Check the load
·
Check that the load is not too heavy.
·
Check that the shaft is not locked.
5) Others
·
Check that the ALARM lamp is not lit.
·
Check that the Pr. 15 "jog frequency" setting is not lower than the Pr. 13 "starting frequency" value.
( 2 ) Motor rotates in opposite direction.
·
Check that the phase sequence of output terminals U, V and W is correct.
·
Check that the start signals (forward rotation, reverse rotation) are connected properly.
( 3 ) Speed greatly differs from the setting.
·
Check that the frequency setting signal is correct. (Measure the input signal level.)
·
Check that the following parameter settings are proper: Pr. 1, Pr. 2, Pr. 902 to Pr. 905, Pr. 19.
·
Check that the input signal lines are not affected by external noise. (Use shielded cables)
·
Check that the load is not too heavy.
( 4 ) Acceleration/deceleration is not smooth.
·
Check that the acceleration and deceleration time settings are not too short.
·
Check that the load is not too heavy.
·
Check that the torque boost (Pr. 0, Pr. 46, Pr. 112) setting is not too large to activate the stall
function.
PROTECTIVE FUNCTIONS
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