American Standard YSC036A Installation, Operation And Maintenance Manual page 9

General Information
nominally, the RTRM will shut off all
mechanical operations, lock the
system out, send a diagnostic to ICS,
and the SERVICE output will flash.
The system will remain locked out
until a reset is initiated either
manually or through ICS.
Clogged Filter Switch (Optional)
The unit mounted clogged filter
switch monitors the pressure
differential across the return air
filters. It is mounted in the filter
section and is connected to the
RTOM. A diagnostic SERVICE signal
is sent to the remote panel if the
pressure differential across the filters
is at least 0.5" w.c. The contacts will
automatically open when the
pressure differential across the filters
decreases to approximately 0.4" w.c.
The clogged filter output is energized
when the supply fan is operating and
the clogged filter switch has been
closed for at least 2 minutes. The
system will continue to operate
regardless of the status of the filter
switch.
Compressor Disable (CPR1/2)
This input incorporates the low
pressure control (LPC) of each
refrigeration circuit and can be
activated by opening a field supplied
contact installed on the LTB.
If this circuit is open before the
compressor is started, the
compressor will not be allowed to
operate. Anytime this circuit is
opened for 1 continuous second
during compressor operation, the
compressor for that circuit is
immediately turned "Off" . The
compressor will not be allowed to
restart for a minimum of 3 minutes
should the contacts close.
If four consecutive open conditions
occur during the first three minutes
of operation, the compressor for that
circuit will be locked out, a diagnostic
communicated to the remote panel
(if installed), and a manual reset will
be required to restart the
compressor.
RT-SVX21F-EN
Low Pressure Control
ReliaTel Control
When the LPC is opened for 1
continuous second, the compressor
for that circuit is turned off
immediately. The compressor will
not be allowed to restart for a
minimum of 3 minutes.
If four consecutive open conditions
occur during an active call for
cooling, the compressor will be
locked out, a diagnostic
communicated to ICS™, if applicable,
and a manual reset required to
restart the compressor. On dual
compressor units only the affected
compressor circuit is locked out.
Electromechanical Control
When the LPC is opened, the
compressor for that circuit is turned
off immediately. The compressor will
restart when the LPC closes.
High Pressure Control
(Optional — except on
R-410A units)
ReliaTel Control
The high pressure controls are wired
in series between the compressor
outputs on the RTRM and the
compressor contactor coils. If the
high pressure control switch opens,
the RTRM senses a lack of current
while calling for cooling and locks the
compressor out.
If four consecutive open conditions
occur during an active call for
cooling, the compressor will be
locked out, a diagnostic
communicated to ICS™, if applicable,
and a manual reset required to
restart the compressor. On dual
compressor units only the affected
compressor circuit is locked out.
Electromechanical Control
When the HPC is opened, the
compressor for that circuit is turned
off immediately. The compressor will
restart when the HPC closes.
Power Exhaust Control
(Optional)
ReliaTel Control
The power exhaust fan is started
whenever the position of the
economizer dampers meets or
exceed the power exhaust setpoint
when the indoor fan is on.
With the optional ventilation override
accessory, the power exhaust fan is
independent of the indoor fan.
The setpoint panel is located in the
return air section and is factory set at
25%.
Electromechanical Control
The power exhaust fan is started
whenever the indoor fan is on and
the adjustable damper limit switch
DLS is closed.
Lead/Lag Control
(Dual Circuit Only)
ReliaTel Control Only
Lead/Lag is a selectable input located
on the RTRM. The RTRM is
configured from the factory with the
Lead/Lag control disabled. To
activate the Lead/Lag function,
simply cut the wire connected to J3-8
at the RTRM. When it is activated,
each time the designated lead
compressor is shut off due to the
load being satisfied, the lead
compressor or refrigeration circuit
switches. When the RTRM is
powered up, i.e. after a power failure,
the control will default to the number
one circuit compressor.
Zone Sensor Module (ZSM)
(BAYSENS006B)
This electronic sensor features three
system switch settings (Heat, Cool,
and Off) and two fan settings (On
and Auto). It is a manual changeover
control with single setpoint. (Cooling
Setpoint Only)
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