KITO Harrington RY Series, Owner'S Manual

Page: 94 / 120

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Table 7-8 "Minor Failure/ Warning" Display Details and Remedies (Continued)
LED display Minor failure name
oH
Heat sink overheat
The VFD heat sink temperature exceeded the setting value (90 to 100°C)
(that varies depending on the VFD capacity)
Cause Measure
The ambient temperature is too
high.
Check the ambient temperature.
⇒
Use it at an ambient temperature of 40oC or lower.
⇒
Remove heating elements nearby, if any.
LED display Minor failure name
ov
Main circuit overvoltage
The main circuit DC voltage exceeded the overvoltage detection level
when no driving command is inputted (when the VFD is not operating).
200V class: Approx. 410V
400V class: Approx. 820V
Cause Measure
Surge voltage was mixed into the input
power supply.
⇒
Install a DC reactor.
⇒
If the phase advance capacitor is turned on/off or the thyristor
conversion
device operates within the same power supply system, an abnormal rapid
rise (surge) of the input voltage may occur temporarily.
A ground fault of the motor occurred.
(A ground-fault current is charging
the main circuit capacitor in the
VFD via the power supply.)
Check the power cable, relay terminal, and motor terminal box of the
motor.
⇒
Remove the part with a ground fault, and turn on the power supply
again.
Malfunction occurred due to noise.
Check the state of the noise measures.
⇒
Check the wiring of the control circuit as well as wiring and ground
wiring of the main circuit, and take sufficient noise measures.
⇒
If the noise generation source is the electromagnetic contactor, connect
a surge absorber to the coil of the electromagnetic contactor.
LED display Minor failure name
CrST
Reset during driving command input
An error reset signal was inputted while the driving command was being
inputted.
Cause Measure
An error reset was inputted while the
driving command was being inputted.
Check if the driving command is inputted from the external terminal or
communication card upon an error reset.
⇒
Turn off the driving command.