In above post #8
TRANSISTORIZED INVERTER
FR-A540-0.4K to 55K(-NA)(-EC)
– INSTRUCTION MANUAL –
Page 174......
CHAPTER 5
PROTECTIVE FUNCTIONS
Always read the instructions before using the equipment.
Page 180..............
(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.
Page 181.............
(5) Motor current is large.
· Check that the load is not too heavy.
· Check that the torque boost (Pr. 0, Pr. 46, Pr. 112) setting is not too large.
(6) Speed does not increase.
· Check that the maximum frequency (Pr. 1) setting is correct.
· Check that the load is not too heavy. (In agitators, etc., load may become heavy in winter.)
· Check that the torque boost (Pr. 0, Pr. 46, Pr. 112) setting is not too large to activate the stall
prevention function.
(7) Speed varies during operation.
During operation under advanced magnetic flux vector control, 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 induced noise.
3) Others
· Check that the settings of the applied motor capacity (Pr. 80) and the number of applied motor poles
(Pr. 81) are correct for the inverter and motor capacities in advanced magnetic flux vector control.
· Check that the wiring length is within 30m (98.42 feet) in advanced magnetic flux vector control.
· Check that the wiring length is correct in V/F control.
(8) Operation mode is not changed properly.
If the operation mode is not changed properly, check the following:
1. External input signal .............Check that the STF or STR signal is off.
When it is on, the operation mode cannot be changed.
2. Parameter setting .................Check the Pr. 79 setting.
When the setting of Pr. 79 "operation mode selection" is "0" (factory
setting), switching input power on places the inverter in the external
operation mode. Press the operation panel's [MODE] key three times
and press the [UP] key (press the [PU] key for the parameter unit
(FR-PU04)). This changes the external operation mode into the PU
operation mode. For any other setting (1 to 8), the operation mode is
limited according to the setting.
Pages 182...185
5.3 Precautions for Maintenance and Inspection
5.3.4 Insulation resistance test using megger
READ CAREFUL
5.3.5 Pressure test
in table READ CAREFUL .... column Method
Pages 188...189
5.3.8 Measurement of main circuit voltages, currents and power
Ps-
Is this the same inverter, in which the parameter was changed "by themselves" ???
if so ...then check parameters related to motor , motor control and power.