Fuji Electric FRENIC-HVAC User Manual page 661

[ 3 ] The motor runs in the opposite direction to the command.
Possible Causes
(1) Wiring to the motor is incorrect.
(2) Incorrect connection and
settings for run commands and
rotation direction commands
FWD and REV.
(3) A run command (with fixed
rotational direction) from the
keypad is active, but the
rotational direction setting is
incorrect.
(4) The rotation direction
specification of the motor is
opposite to that of the inverter.
[ 4 ] Speed fluctuation or current oscillation (e.g., hunting) occurs during
running at constant speed.
Possible Causes
(1) The frequency command
fluctuates.
(2) An external frequency
command potentiometer is
used for frequency setting.
(3) Frequency switching or
multi-frequency command was
enabled.
(4) The wiring length between the
inverter and the motor is too
long.
(5) The machinery is hunting due
to vibration caused by low
rigidity of the load. Or the
current is irregularly oscillating
due to special motor
parameters.
What to Check and Suggested Measures
Check the wiring to the motor.
 Connect terminals U, V, and W of the inverter to the U, V, and W
terminals of the motor, respectively.
Check the data of function codes E98 and E99 and the connection to
terminals [FWD] and [REV].
 Correct the data of the function codes and the connection.
Check the data of function code F02 (Run command).
 Change the data of function code F02 to "2:
keypad (forward)" or "3:
The rotation direction of IEC-compliant motors is opposite to that of
incompliant motors.
 Switch the FWD/REV signal setting.
What to Check and Suggested Measures
Check the signals for the frequency command with Menu #4 "I/O
Checking" using the keypad.
 Increase the filter constants (C33, C38, and C43) for the frequency
command.
Check that there is no noise in the control signal wires from external
sources.
 Isolate the control signal wires from the main circuit wires as far as
possible.
 Use shielded or twisted wires for control signals.
Check whether the external frequency command potentiometer is
malfunctioning due to noise from the inverter.
 Connect a capacitor to the output terminal of the potentiometer or
set a ferrite core on the signal wire. (Refer to Chapter 2.)
Check whether the relay signal for switching the frequency command is
chattering.
 If the relay contact is defective, replace the relay.
Check whether auto-torque boost, auto-energy saving operation, or
dynamic torque vector control is enabled.
 Perform auto-tuning of the inverter for every motor to be used.
 Disable the automatic control systems by setting F37 to "1"
(Constant torque load) and F42 to "0" (V/f control with slip
compensation active), then check that the motor vibration stops.
 Make the output wires as short as possible.
Once disable all the automatic control systems such as auto torque boost,
auto energy saving operation, overload prevention control, current
limiter, torque limiter, automatic deceleration (anti-regenerative
control), auto search for idling motor speed, slip compensation, dynamic
torque vector control, online tuning, and then check that the motor
vibration comes to a stop.
 Disable the functions causing the vibration.
 Readjust the output current fluctuation damping gain (H80).
Check that the motor vibration is suppressed if you decrease the level of
F26 (Motor sound (Carrier frequency)) or set F27 (Motor sound (Tone))
to "0."
 Decrease the carrier frequency (F26) or set the tone to "0" (F27 = 0).
9-27
9.4 Nothing appears on the monitor
/
/ keys on keypad (reverse)."
keys on