Instruction manual

PROTECTIVE FUNCTIONS
194
5.2.6 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.
Check that the brake resistor is not connected to terminals P
〈
+
〉
-P1 by mistake.
5.2.7 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.
Check that a malfunction does not occur due to an undesirable current when the transistor output unit
is connected, for example. (Refer to page 18.)
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.
5.2.8 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 two times and
press the
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.
5.2.9 Operation panel (FR-DU04) display is not provided
Make sure that the operation panel is connected securely with the inverter.
5.2.10 POWER lamp is not lit
Make sure that the wiring and installation are correct.
5.2.11 Parameter write cannot be performed
Check that operation is not being performed (signal STF or STR is not ON).
Check that the
SET
key (
WRITE
key) is pressed for longer than 1.5 seconds.
Check that you are not attempting to make parameter setting outside the setting range.
Check that you are not attempting to make parameter setting in the external operation mode.
Check the setting of Pr. 77 "parameter write inhibit selection".