PROTECTIVE FUNCTIONS
173
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5.2.3 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 correct (Pr. 1, Pr. 2, Pr. 19,
Pr. 38, Pr. 39, Pr. 245, Pr. 902 to Pr. 905).
Check that the input signal lines are not affected by external noise. (Use shielded
cables)
Check that the load is not too heavy.
5.2.4 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 setting is not too large to activate the stall prevention
function.
5.2.5 Motor current is large
Check that the load is not too heavy.
Check that the torque boost setting is not too large.
5.2.6 Speed does not increase
Check that the maximum frequency setting is correct.
Check that the load is not too heavy. (In agitators, etc., load may become heavier
in winter.)
Check that the torque boost setting is not too large to activate the stall prevention
function.
Check that the brake resistor is not connected to ter - 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
Check that the load is not varying.
(2) Inspection of input signal
Check that the frequency setting signal is not varying.
Check that the frequency setting signal is not affected by noise.
Check that a malfunction does not occur due to an undesirable current when
the transistor output unit is connected, for example. (Refer to page 23.)
3) Others
Check that the setting of the applied motor capacity (Pr. 80) is correct for
the inverter capacities in general-purpose magnetic flux vector control.
Check that the wiring length is within 30m in general-purpose magnetic
flux vector control.
Check that the wiring length is correct in V/F control.
