Troubleshooting For Output Circuit - Mitsubishi Electric CC-Link IE-NZ2GNSS2-8D User Manual

Troubleshooting for output circuit

This section describes the troubleshooting for output circuit.
A load momentarily turns on from off when the system is powered off
■Cause
When an inductive load is connected, the load [2] in the off state may turn on due to a sneak current from the back EMF at the
shutoff [1].
Back electromotive
Source output
force
Y0
ON
[2]
Y1
OFF
COM-
IO24V
IO24G
■Action
Take one of the two actions shown below.
• To suppress the back EMF, connect a diode in parallel with the load under the back EMF influence [3].
Back electromotive
-
+
force
Load
• Configure another current path by connecting a diode across positive and negative of the external power supply.
Back electromotive
Source output
force
Y0
ON
[2]
Y1
OFF
COM-
D1
IO24V
IO24G
D1 indicates the following.
*1
Reverse voltage VR (VRM)
*2
Forward current IF (IFM)
*1 Approximately 10 times the rated load voltage in the specifications
Example: 24VDC  Approx. 200VDC
*2 Twice the maximum load current (common) in the performance specifications or more
Example: 4A/1 common  8A or more
[3]
Load
Load
[1] Shut off
[3]
Load
Load
[1] Shut off
10 TROUBLESHOOTING
10.5 Fault Examples with the Safety Remote I/O Module
10
115