Installation Instructions

Document No. 550-169
Installation Instructions
October 26, 2016
Page 4 of 9 Siemens Industry, Inc.
Wiring Diagrams
Offboard Air Module Wiring.
CAUTION
The FHC-OAVS has two terminal
blocks with terminations numbered
identically (terminations 1 through
16). DO NOT get these mixed up
with each other.
If the FHC-OAVS is not connected
as shown, it is not resistant to
electrical surges. It is also
susceptible to interference from
other equipment.
CAUTION
A separate power supply is required
if a 4-20 mA sensor is used.
Failure to follow wiring precautions
will result in equipment damage.
Wiring for AI5: Sash Sensor 1.
Wiring for AI4: Sash Sensor 2.
WARNING
The application cannot detect a
broken wire to the analog input for
the second sash.
An external sash aggregating
device should be used to
calculate the face area for all
fume hoods with more than one
sash.
WARNING
Must use external 10 Vdc power
supply.
Do not power AI from an onboard
AO that is forced to 10 volts.
Wiring for AI with a 4 to 20 mA Sensor.