Troubleshooting For Output Circuit - Mitsubishi Electric NZ2GN2S1-32D User Manual

Troubleshooting for output circuit

This section describes the troubleshooting for output circuit.
A load momentarily turns on when the external power supply is powered on
■Cause
An incorrect output occurs due to the stray capacitance (C) between collector and emitter of a photocoupler.
(When a high sensitivity load (such as solid state relay) is used, this incorrect output may occur.)
Output module
Photocoupler
C
Tr1
Ic
Constant-
voltage circuit
When the external power supply is powered on rapidly, the current (Ic) flows due to the stray capacitance(C).
The current (Ic) flows to the gate of the transistor (Tr1) of the next stage and the output Y0 turns on for approximately 100s.
SW: External power
supply (24V)
at On
Output Y0
Y0
Load
CTL+
SW
COM-
24V
10ms or less
Approx.100μs
11 TROUBLESHOOTING
11.5 Examples of Troubles with the I/O Module
11
147