User`s manual

6 - 28
6 INSPECTION AND MAINTENANCE
(c) The power capacity of the resistor selected is 3 to 5 times greater than the
actual current consumption. 220 [
], 10 to 15 [W] resistor may therefore be
connected to the terminal in question.
(2) Output circuit troubleshooting
The following describes possible problems with output circuits and their
corrective actions.
Output Circuit Troubleshooting and Corrective Action
Condition Cause Corrective action
Example 1
Excessive
voltage is
applied to
load when
output turns
OFF
• When load is half-wave rectified
(This is typical some solenoids).
Output module
D1
Load
1)
2)
C
• When the polarity of the power supply is [1],
the capacitor C is charged. When the
polarity is [2], the voltage charged in C plus
the power supply voltage is applied to across
D1. The maximum value of the voltage is
approx. 2.2E. (This usage does not pose
problems to the output components but may
deteriorate the diode built in the load,
causin
g
burnout
,
etc.
)
.
• Connect a resistor of several ten k
to
several hundred k across the load.
Load
Resistor
Example 2
Load does
not turn OFF
(Triac output).
• Leakage current due to built-in surge
suppressor.
Output module
Load
Leakage current
• Connect a resistor across the load.
(If the wiring from the output module to the
load is long, be careful since there may be a
leakage current due to the line capacity.)
Load
Resistor