Operation
RT-SVX19A-E4
54
ReliaTel™ is a microelectronic
control feature, which provides
operating functions that are
significantly different from
conventional electro-mechanical
units. The master module is the
ReliaTel™ Refrigeration Module
(RTRM).
The RTRM provides compressor
antishort cycle timing functions
through minimum "Off" and "On"
timing to increase reliability,
performance and to maximize unit
efficiency.
Upon power initialization, the RTRM
performs self-diagnostic checks to
insure that all internal controls are
functioning. It checks the
configuration parameters against
the components connected to the
system.
The LED located on the RTRM
module is turned "On" within one
second after power-up if all internal
operations are okay.
Cooling without an
Economizer
When the system switch is set to
the "Cool" position and the zone
temperature rises above the cooling
setpoint controlband, the RTRM
energizes the (K9) relay coil located
on the RTRM. When the K9 relay
contacts close, the compressor
contactor (CC1) coil is energized
provided the low pressure control
(LPC1) and high pressure control
(HPC1) are closed. When the CC1
contacts close, compressor (CPR1)
and the outdoor fan motor (ODM)
start to maintain the zone
temperature to within ± 2 F of the
sensor setpoint at the sensed
location.
If the first stage of cooling can not
satisfy the cooling requirement, the
RTRM energizes the (K10) relay coil
located on the RTRM. When the
(K10) relay contacts close, the
compressor contactor (CC2) coil is
energized provided the low
pressure control (LPC2) and high
pressure control (HPC2) are closed.
When the CC2 contacts close,
compressor (CPR2) starts to
maintain the zone temperature to
within ± 2 F of the sensor setpoint
at the sensed location.
Evaporator Fan Operation
When the fan selection switch is set
to the "Auto" position, the RTRM
energizes the (K6) relay coil
approximately one second after
energizing the compressor
contactor coil (CC1) in the cooling
mode. In heating mode, the RTRM
energizes the (K6) relay coil
approximately 45 seconds after gas
ignition. Closing the K6 contacts on
the RTRM energizes the supply fan
relay (F) coil to start the supply fan
motor (IDM).
The RTRM de-energizes the fan
relay (F) approximately 60 seconds
after the cooling requirement has be
satisfied to enhance unit efficiency.
When the heating cycle is
terminated, the supply fan relay (F)
coil is de-energized approximately
90 seconds after the heating
requirement.
When the fan selection switch is set
to the "On" position, the RTRM
keeps the supply fan relay coil (F)
energized for continuous fan motor
operation.
When the unit is equipped with the
optional clogged filter switch, wired
between terminals J7-3 and J7-4 on
the ReliaTel™ Options Module
(RTOM), the RTRM produces an
analog output if the clogged filter
switch (CFS) closes for two minutes
after a request for fan operation.
When the system is connected to a
remote panel, the "SERVICE" LED
will be turned on when this failure
occurs.
