Speed Greatly Differs From The Setting; Acceleration/Deceleration Is Not Smooth; Motor Current Is Large; Speed Does Not Increase - Mitsubishi Electric FR-E500 Instruction Manual

5.2.3 Speed greatly differs from the setting

y Check that the frequency setting signal is correct. (Measure the input signal
level.)
y Check that the following parameter settings are correct (Pr. 1, Pr. 2, Pr. 38,
Pr. 39, Pr. 245, Pr. 902 to Pr. 905, Pr. 19).
y Check that the input signal lines are not affected by external noise. (Use shielded
cables)
y Check that the load is not too heavy.

5.2.4 Acceleration/deceleration is not smooth

y Check that the acceleration and deceleration time settings are not too short.
y Check that the load is not too heavy.
y Check that the torque boost setting is not too large to activate the stall prevention
function.

5.2.5 Motor current is large

y Check that the load is not too heavy.
y Check that the torque boost setting is not too large.

5.2.6 Speed does not increase

y Check that the maximum frequency setting is correct.
y Check that the load is not too heavy. (In agitators, etc., load may become heavier
in winter.)
O
Check that the torque boost setting is not too large to activate the stall prevention
function.
O
Check that the brake resistor is not connected to terminals P (+) - P1 accidentally.

5.2.7 Speed varies during operation

When slip compensation is selected, the output frequency varies with load fluctuation
between 0 and 2Hz. This is a normal operation and is not a fault.
1) Inspection of load
y Check that the load is not varying.
2) Inspection of input signal
y Check that the frequency setting signal is not varying.
y Check that the frequency setting signal is not affected by noise.
3) Others
y Check that the setting of the applied motor capacity (Pr. 80) is correct for the
inverter capacities in general-purpose magnetic flux vector control.
y Check that the wiring length is within 30m (98.42 feet) in general-purpose
magnetic flux vector control.
y Check that the wiring length is correct in V/F control.
PROTECTIVE FUNCTIONS
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