Outdoor Thermostat(S) - Bryant R-22 Application Manual And Service Manual

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either heating or cooling. This enables owner to obtain timely
heat-pump service during heating season, reducing supplementary
electric heat costs, and during cooling season, reducing period of
heat discomfort.
The service alarm is an accessory device. Service alarm locks out
compressor under certain adverse operating conditions. System is
manually reset by shutting it off at thermostat subbase, then
turning it back on. If adverse condition is corrected, system
restarts.
One example of an adverse condition would be a system located in
a desert climate where high operating temperatures may cause
system to shut down on the high-pressure switch or on the
compressor internal overload.
Connect service alarm to outdoor-unit control-circuit-terminal
board. (See Fig. 25 and wiring diagram on unit.)
Connect all field line-power wires to unit in usual manner. Route
1 field line-power supply wire through metallic loop on bottom of
service alarm then to normal unit connection. Units with RLA of
less than 14 amps will require 2 passes through the metallic loop.
Refer to Fig. 25 or 26 for wiring connections for service alarm or
service alarm with solid-state cycle-protector accessories, when
used.
NOTE: The wire from the X terminal on the service alarm to L on
the outdoor terminal board, indoor terminal board, and thermostat
subbase is field-supplied and wired when using defrost controls
HK32FA003 or HK32FA006. When defrost control CES0110063
or CES0130024 is used, field-supplied wire from X terminal on
service alarm to L on indoor thermostat subbase is required.
Quiet Defrost interval
Shift DIP switches
Fig. 22—Defrost Control
—22—
CESO130076–00
Service alarm requires 2 inputs.
1. It must sense a 24v input from thermostat. As thermostat
calls for heating or cooling, it supplies 24v to service-alarm
device.
2. A current transformer (or induction loop) similar to a
clamp-on ammeter senses current draw in the compressor
lead. Induction loop must sense a minimum current draw
when thermostat is calling for heating or cooling.
NOTE: On a single-phase compressor, induction loop senses
current in common leg. On a 3-phase compressor, induction loop
senses current in any 1 of the phases.
WARNING: If service alarm needs replacing, shut off
all power to unit before attempting removal. Electrical
shock can cause personal injury or death.
Troubleshooting service-alarm device is easy. With thermostat
calling for heating or cooling and compressor running, indoor
thermostat light should be off. If on, check for wiring errors or
replace the service alarm.
To check for correct operation, shut off circuit breaker or discon-
nect switch to outdoor unit while it is running. Signal light on
thermostat should light. If this does not occur, check for wiring
errors or replace the service alarm.
XII. OUTDOOR THERMOSTAT(S)
The outdoor thermostat(s) is installed in the control box. The
sensing bulb(s) remain in the control box. Outdoor thermostat
brings on stages of electric heat as outdoor temperature and
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