Trane LPC Install And Operation Instructions page 61

LPC-SVX01C-EN
Operation
Table O-GI-13. Exhaust Fan Status Binary IN 12 Configuration
IN 12
Configuration Contact Closed
Not used Normal
Normally closed Exhaust fan diagnostic
Normally open Normal
Note 1: A Low Exhaust Fan Air Flow diagnostic is generated when the controller turns on the exhaust fan output, but the
exhaust fan status binary input indicates the exhaust fan is not running after a 2 minute time delay. This diagnostic is
IN12: Exhaust fan status or coil defrost
Binary input IN12 can be configured
either as an exhaust fan status input or a
coil defrost input.
Exhaust fan status
When configured as an exhaust fan
status binary input, IN12 indicates the
presence of air flow through an exhaust
fan associated with the controlled air-
handling unit. For Tracer AH540/541
applications, a differential pressure
switch detects exhaust fan status, with
the high side of the differential being
supplied at the outlet. During exhaust fan
operation, differential pressure closes the
normally open switch and confirms that
the fan is operating properly.
general
information
Contact Open
Normal
(Note 1)
Normal
Exhaust fan diagnostic (Note 1)
A Low Exhaust Fan Air Flow diagnostic is
detected during the following two
conditions:
1. The controller is commanding the
exhaust fan On and the status switch
is not in the closed position.
2. The fan status switch does not close
the binary input within two minutes
of the controller commanding the
exhaust fan On.
Although the fan status switch is normally
open, it is configurable
(see Table O-GI-13).
Coil defrost
Binary input IN12 can be configured as a
coil defrost input.
See the "Coil defrost" section.
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