6- 13
Installation Conditions and Method
6
Note
The constant voltage power supply (24VDC) connected to the IV-S20 main housing should
not be ground its positive terminal.
- If the positive terminal of the constant voltage power supply is grounded while using
external equipment connected to the SG or FG terminals, the short circuit shown below will
be created. This circuit will let a large current flow through the SG line inside the IV-S20,
and may destroy the circuit, or cause smoke or a fire.
- If the positive terminal of the 24 VDC power supply must be grounded for facility
construction reasons, make sure to provide an independent power supply (exclusively for
use with the IV-S20) which does not ground either the positive or negative terminals.
;;;;;;;;;;;;;;;
RS-232C
/
RS-422
SG
FG
SG
(-)
(+)
FG
Grounded positive line
External equipment
(monitor or the like)
IV-S20 main
housing
Constant voltage power
supply (24 VDC)
for the IV-S20
When the SG or FG conduct current
inside the external equipment
Wraparound current
Installation floor