When Two Or More Inverters Are Connected - Mitsubishi Electric FR-A7NC E kit-SC Instruction Manual

9.2

When two or more inverters are connected

The following system configuration shows how the cause of a fault can be checked with the LED status of
the inverter communication option (FR-A7NC) and countermeasures for the fault.
(In this example, assume SW, M/S, and PRM LEDs of the master module are OFF (master module is in
normal operation).)
Power
supply
LED Status
Inverters (FR-A7NC)
Master
Module
Station 1 Station 2 Station 3
RUN  RUN
L.RUN  L.RUN 
SD  SD
TIME 
RD  RD
LINE

L.ERR  L.ERR 
or
RUN  RUN
TIME 
L.RUN  L.RUN 
LINE 
SD  SD
RD  RD
L.ERR  L.ERR 
HOW TO CHECK FOR ERROR USING THE LEDS
CPU Master
module
Station 1
Inverter A
FR-A7NC
 RUN 
L.RUN 
SD Normal
 
 RD 
L.ERR 
 RUN 
L.RUN 
Poor contact of the FR-A7NC with the
 SD 
inverter
 RD 
L.ERR 
Station 2
Inverter B
FR-A7NC
Cause
: ON, : OFF, : Flicker, *: Any of ON, flicker or OFF
  
Station 3
Inverter C
FR-A7NC
Corrective Action

Plug the FR-A7NC securely.
Check the connector.
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