Bryant R-22 service manual OF2 CESO130076–00

	T2 C
	C
	O
O	DFT
R	T1
W

2

Y
C	Y
SPEEDUP	P1
	J1	P3	90 INTERVALTIMER	60 30	30 60	120
	DFT		OFF	QUIET SHIFT		ON
	Speedup				Quiet
	Pins				Shift

OF2

CESO130076–00

Defrost interval

DIP switches

Fig. 22—Defrost Control

OF1

A99442

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.

—22—

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