Rockwell Automation Publication 8720MC-RM001K-EN-P - September 2018
101
Troubleshoot the 8720MC-RPS Unit
Chapter 8
Table 30 - Error Codes Common to All 8720MC-RPS Units
Error Code
Error Description
Error Cause
Corrective Action
PrC
Precharge Error
The DC-bus voltage did not reach a certain level
in precharge even if the precharge/discharge
time has elapsed.
Check that the set value of the Precharge/ Discharge Time (F.014) is correct. If no
other problem is found, increase the set value.
Precharge/discharge resistor or its wiring is faulty. Check the resistor and wiring,
and remove the cause. If Fuse 1 the precharge fuse is blown, replace the fuse.
Check that the recommended line reactor has been selected.
CHr
Precharge/Discharge
Overload Error
The precharge/discharge resistor is in overload
condition.
Do not perform precharge and discharge for a while.
Replace the precharge/discharge resistor with one having a larger wattage, and
set again the Wattage of Precharge/Discharge Resistor (F.015).
oL
Overload Error
Output current is excessive.
Check that the power rating of the unit is adequate for the input of the load.
Decrease the input of the load.
AC
AC Input Frequency or
High Voltage Error
The AC input power frequency exceeds the base
frequency (50 Hz or 60 Hz) by +/-3% or more.
Check the AC input power supply.
There is large distortion (notches) in AC input
power voltage.
The AC input power is too high.
Check that the set value of the AC Overvoltage Detection Level (F.009) is
adequate. If no other problem is found, increase the set value.
HU
High Bus-voltage Error
The DC-bus voltage is too high.
Check the AC input power voltage.
Check that the set value of the Voltage Control Proportional Gain (F.005) is
adequate.
Check that the set value of the Bus Overvoltage Detection Level (F.007) is
adequate. If no other problem is found, increase the set value.
The capacity of the AC reactor is too large. Replace it with a reactor having a
smaller capacity.
The load change is too fast. Reduce the load change speed.
LU
Low Bus-voltage Error
The DC-bus voltage is too low.
Check the AC input power voltage and the line fuse.
Check that the set value of the Allowable Time for Instantaneous Power Loss
(F.012) is adequate. If no other problem is found, increase the set value.
IPL
Input Phase Loss Error
Phase loss occurred for the AC input power.
Check the AC input power voltage and the line fuse.
Power loss occurred (The allowable time for
instantaneous power loss was exceeded.)
Check that the set value of the Allowable Time for Instantaneous Power Loss
(F.012) is adequate. If no other problem is found, increase the set value.
Con
Magnetic Contactor Error
No answer-back signal was received from the
main magnetic contactor.
Check the operation of the main magnetic contactor.
Verify that the answer-back signal of the main magnetic contactor is correctly
wired to the sequence input signal terminal.
Fr
Faulty Relay Signal
An error was issued from the Power Interface
Board (PIFS). Detailed descriptions of error
factors cannot be read out.
Verify that the Regulator Board and the Power Interface Board are inserted
correctly.