
Low-PressureSwitch--(SelectModels)Alow-
pressureswitchisfactory-installedandlocated
inthesuctionlineinterna!to theoutdoorunit.
Theswitchisdesignedtoprotectthecompressor
fromalossofcharge.Undernormalconditions,
theswitchisclosed.Ifthesuctionpressurefalls
below5psig,thentheswitchwillopenandde-
energizetheoutdoorunit.Theswitchwillclose
againoncethesuctionpressureincreasesabove
20 psig.Pleasenotethattheswitchinterrupts
thethermostatinputstotheunit.Thuswhenthe
switchopensandthencloses,therewillbea5
minuteshortcyclingdelaybeforetheoutdoor
unitwillenergize.
High-PressureSwitch--AHigh-pressureswitch
isfactory-installedandlocatedinthecompressor
dischargelineinternaltotheoutdoorunit.The
switchisdesignedto de-energizethesystem
whenveryhighpressuresoccurduringabnormal
conditions.Undernormalconditions,theswitch
isclosed.Ifthedischargepressurerisesabove
575psig,thentheswitchwillopenandde-ener-
gizetheoutdoorunit.Theswitchwillcloseagain
oncethedischargepressuredecreasesto460
psig.Pleasenotethattheswitchinterruptsthe
thermostatinputsto theunit.Thus,whenthe
switchopensandthencloses,therewillbea5
minuteshortcyclingdelaybeforetheoutdoor
unitwillenergize.
ComfortAlert TM Diagnostics (Select Models)
-- The Comfort Alert TM diagnostics module
facilitates troubleshooting heat pump and air
conditioning system failures. This Comfort
Alert TM module isdesigned only for single-phase
systems with scroll compressors that have
internal overload protection. By monitoring and
analyzing data from the compressor and the
thermostat demand, the module can detect the
cause of electrical and system related failures
without any sensors. A flashing LED indicator
communicates the ALERT code and guides the
service technician more quickly and accurately
to the root cause of a problem.
NOTE: This module does not provide safety
protection! The Comfort Alert TM module is a
monitoring device and cannot control or shut
down other devices.
LED Description (See Figure 2)
POWER LED (Green): indicates voltage ispresent
at the power connection of the module.
ALERT LED (Yellow): communicates an
abnormal system condition through a unique
flash code. The ALERT LED will flash a number
of times consecutively, pause and then repeat
the process. The number of consecutive
flashes, defined as the Flash Code, correlates
to a particular abnormal condition. Detailed
descriptions of specific ALERT Flash Codes are
shown in Table 1 of this manual.
TRIP LED (Red): indicates there is a demand
signal from the thermostat but no current to the
compressor is detected bythe module.TheTRIP
LED typically indicates the compressor protector
is open or may indicate missing supply power
to the compressor.
The scroll compressor's run (R), common (C)
and start (S) wires are routed through the holes
in the Comfort Alert TM module marked "R," "C"
and "S."
24 VAC Power Wiring -- The Comfort Alert TM
module requires a constant nominal 24 VAC
power supply. The wiring to the module's R and
C terminals must be directly from the indoor unit
or thermostat.
The Comfort Alert TM module requires athermostat
demand signal to operate properly.
NOTE: After the thermostat demand signal is
connected, verify that 24 VAC across Y and C
when demand is present.
TROUBLESHOOTING
interpreting The Diagnostic LEDs - When
an abnormal system condition occurs, the
Comfort Alert TM module displays the appropriate
ALERT and/or TRiP LED will flash a number of
times consecutively, pause and then repeat the
process.To identify a Flash Code number, count
the number of consecutive flashes.
Every time the module powers up, the last
ALERT Flash Code that occurred prior to shut
down is displayed for one minute. The module
will continue to display the LED until the condition
returns to normal or if24 VAC power is removed
from the module.
Cooling -- Gradually lower the thermostat
temperature setpoint below the actual room
temperature and observe that the outdoor unit
and indoor blower energize. Feel the air being