General Information
8
RT-SVX39B-EN
Supply Fan Failure Input (Optional)
The Fan Failure Switch can be connected to sense indoor
fan operation:
FFS (Fan Failure Switch) If air flow through the unit is not
proven by the differential pressure switch connected to the
RTRM (factory set point 0.07 “w.c.) within 40 seconds
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.
Note:
On units equipped with factory installed MERV 13
filters, a clogged filter switch with different
pressure settings will be installed. This switch will
close when the differential pressure is
approximately 0.8' w.c. and open when the
differential falls to 0.7" w.c.
Condensate Drain Pan Overflow Switch
(Optional)
ReliaTel Option
This input incorporates the Condensate Overflow Switch
(COF) mounted on the drain pan and the ReliaTel Options
Module (RTOM). When the condensate level reaches the
trip point for 6 continuous seconds, the RTOM will shut
down all unit functions until the overflow condition has
cleared. The unit will return to normal operation after 6
continuous seconds with the COF in a non-tripped
condition. If the condensate level causes unit shutdown
more than 2 times in a 3 days period, the unit will be
locked-out of operation requiring manual reset of
diagnostic system through Zone Sensor or Building
Automation System (BAS). Cycling unit power will also
clear the fault.
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.
Low Pressure 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.
High Pressure 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.
Lead/Lag Control (Dual Circuit 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) (BAYSENS107*)
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)
Zone Sensor Module (ZSM) (BAYSENS109*)
This electronic sensor features four system switch settings
(Heat, Cool, Auto, and Off) and two fan settings (On and
Auto). It is a manual or auto changeover control with dual
setpoint capability. It can be used with a remote zone
temperature sensor BAYSENS077*.
