Faults In The Output Circuit - Mitsubishi A1SJH(S8) User Manual

11. TROUBLESHOOTING

11.4.2 Faults in the output circuit

Faults concerning output circuits and the corrective actions are explained.
Situation
An excessive voltage is
Example
applied to the load when
1
output is off.
Example Load does not turn OFF.
2 (Triac output)
Table 11.3 Faults with the output circuit and the corrective actions
Cause
• When the load is subjected to half wave
rectification inside
(Solenoids have these types.)
A1SY22
Output module
• When the polarity of the power supply is [1], C
is charged, and when the polarity is [2], the
voltage charged in C + voltage of the power
supply are applied to the both ends of D1.
The maximum value of the voltage is about
2.2E.
• Leak current caused by built-in noise
supressor
A1SY22
Output module
Leakage current
• Connect a resistor with several tens to
[1]
D1
Load
[2]
• Connect a resistor to the both ends of the
Load
11 - 19
Countermeasure
several hundreds of k to the both ends of
the load.
With this kind of usage, there is no problem
with the output element, but the diode built-
in to the load may deteriorate and burn-out.
Resister
Load
load.
When the wiring distance from the output
card to the load is long, be aware of the risk
of a leak current due to line capacity.
Resister
Load