Hitachi WL200 Series - Page 93

91
Inverter doesn’t block the current flowing into itself when it is not powered. This may
cause the closed circuit when two or more inverters are connected to common I/O
wiring as shown below to result in unexpected turning the on the input. This may lead
to dangerous situation. To avoid this closed circuit, please put the diode
(rated:50V/0.1A) in the path as described below.
IF the protection diodes used when the units are in wired parallel are only single diodes
then their condition would be checked as part of the proof test.
By having ability inverter doesn’t block the current flowing into itself when it is not powered.
This may cause the closed circuit when two or more inverters are connected to common I/O
wiring as shown below to result in unexpected turning the on the input. To avoid this closed
circuit, please put the diode (rated:50V/0.1A) in the path as described below.
In case of Sink logic
In case of Source logic
Power ON
Power ON
Jumper
wire
Inserting
diode
P24
PLC
L
1
P24
PLC
L
1
Switch
OFF
Power OFF
Input
ON
P24
PLC
L
1
P24
PLC
L
1
Switch
OFF
Power OFF
Input
OFF
Jumper
wire
1
Switch
OFF
Switch
OFF
Input
OFF
Input
ON
P24
PLC
L
P24
PLC
L
P24
PLC
L
P24
PLC
L
1
1
1
Jumper
wire
Jumper
wire
The current loop cause turn the input ON even the
switch is off when diode is not inserted.
The current loop is to be prevented by inserting
diode instead of short bar.