14
CNT-SVX05A-EN
Binary inputs
Generic binary input
Binary input IN 9 can be configured as a generic binary input for a variety of
applications with Trane Tracer Summit
™
only. The binary input does
not
affect
controller operation. Binary input IN 9 can be configured as Occupancy or
Generic. A generic binary input can be monitored only from Tracer Summit.
Supply fan status
The fan status binary input IN 10 indicates the presence of air flow through the
supply fan of an air handling unit. For Tracer
™
AH.540 applications, a differential
pressure switch detects fan status, with the high side of the differential being
supplied at the unit outlet and the low side supplied inside the unit. During fan
operation, differential pressure closes the normally open switch and confirms
that the fan is operating properly.
A
Low Supply Fan Air Flow
diagnostic is detected during the following two
conditions:
• The controller is commanding the fan On and the fan status switch is not in
the closed position
• The fan status switch does not close the binary input within the configurable
fan On delay time limit of the controller commanding the fan On
This is a latching diagnostic and discontinues unit operation until the diagnostic
is cleared from the controller. Additional details can be found in the
Troubleshooting
section.
Table 14 — Fan status binary input IN 10 configuration
Note 1:
A
Low Supply Fan Air Flow
diagnostic is generated when the controller turns on the supply fan output, but the
supply fan status binary input indicates the supply fan is not running after the configurable fan delay time.
Filter status
The filter status switch connected to binary input IN 11 detects a dirty air filter
and indicates a need for maintenance. For Tracer AH.540 applications, a
differential pressure switch detects filter status, with the high side of the
differential being supplied at the filter inlet and the low side supplied at the filter
outlet. During fan operation, filter differential pressure increases as the filter
becomes increasingly dirty.
A normally open filter status switch closes when the differential pressure
reaches a set threshold. This is a non-latching, informational diagnostic and the
controller will continue normal unit operation.
Table 15 — Filter status configuration
IN 10 configuration
Contact closed
Contact open
Not used
Normal
Normal
Normally closed
Latching diagnostic (Note 1)
Normal
Normally open
Normal
Latching diagnostic (Note 1)
IN 11 configuration
Contact closed
Contact open
Not used
Clean
Clean
Normally closed
Clean
Dirty
Normally open
Dirty
Clean