LS Industrial Systems XBC-DR10E - Output Circuit and Corrective Actions

Chapter 10 Maintenance
XBC E-Type Main Unit 10-12 Ver. 1
Input signal
doesn’
t turn
off.
 Leakage current due to the use of two
different power supplies.
 Use only one power supply.
 Connect a blocking diode.
10.4.2 Output circuit and corrective actions
The following describes possible troubles with output circuits, as well as their corrective actions.
Condition
Cause
Corrective Action
When the output
is off, excessive
voltage is
applied to the
load.
Load is half-
wave rectified inside (in some
cases, it is true of a solenoid)

When the polarity of the power supply is as
shown in ①, C is charged. When the polarity is
as shown in ②, the voltage charged in C plus the
line voltage are applied across D. Max. voltage is
approx. 2√2.
*) If a resistor is used in this way, it does not pose
a problem to the output element. But it may make
the performance of the diode (D), which is built in
the load, drop to cause problems.
 Connect resistors of tens to hundreds KΩ
across the load in parallel.
The load
doesn’t
turn off.
 Leakage through a surge suppressor connected
in parallel to the load.
 Use an RC circuit across the load. Wire length
from the output module to the load is long, there
may be a leakage current due to line capacitance.
E
DC input
L
E
E1
DC input
L
E
R
Load
R
Load
C
C
R
Load
Output
~
C
R


Load
D
~
C
R
Load
R
D
~