Sequence of Operation

LIQUID TEMPERATURE AT LIQUID VALVE (C)

Fig. 19A — 575B072 Charging Chart

		140
	(F)	130
	(F)	ADD CHARGE IF ABOVE CURVE
	VALVE	ADD CHARGE IF ABOVE CURVE
		120

	AT LIQUID	110
	AT LIQUID	100
	TEMPERATURE	100
		90
		80

	LIQUID	70
	LIQUID	REDUCE CHARGE IF BELOW CURVE
		60
		50

50	100	150	200	250	300	350	400
		LIQUID PRESSURE AT LIQUID VALVE (PSIG)
344	689	1034	1379	1724	2069	2414
		LIQUID PRESSURE AT LIQUID VALVE (Kilopascals)

Fig. 19B — 575C090,120 Charging Chart

Fig. 19C — 541A180 Charging Chart

I. 575B072 UNITS

When power is supplied to unit, the transformer (TRAN) and crankcase heater (CCH) are energized.

A. Cooling

On a call for cooling, the thermostat completes the following circuits: R-G, R-Y, and R-O. If the compressor recycle delay of 3 minutes is complete, the compressor and outdoor fan start. The reversing valve is energized for cooling and the indoor- fan motor starts.

When the thermostat is satisfied, the circuits are opened, and the compressor, outdoor-fan motor, and indoor-fan motor stop. The reversing valve is deenergized.

B. Heating

On a call for heating, the thermostat completes the following circuits: R-G and R-Y. If the compressor recycle delay of 3 minutes is complete, the compressor and outdoor fan start. The indoor-fan motor will also start.

If room temperature continues to fall, the thermostat completes circuit R-W. If the optional electric heat package is used, the heat relay is energized, and the electric heaters are energized.

When the thermostat is satisfied, the circuits are opened, and the compressor, outdoor-fan motor, heaters, and indoor- fan motor stop.

C. Defrost

Defrost board (DB) is a time and temperature control, which includes a field-selectable time period between checks for frost (30, 50, and 90 minutes). Electronic timer and defrost cycle start only when contactor is energized and defrost ther- mostat (DFT) is closed (below 28 F).

Defrost mode is identical to Cooling mode, except outdoor-fan motor (OFM) stops and a bank of supplemental electric heat turns on to warm air supplying the conditioned space. Defrost mode is terminated when the DFT reaches 65 F.

D. Air Circulation

When the fan switch is at FAN ON, the indoor-air fans oper- ate continuously to provide ventilation. The thermostat operates the other components as described above.

E. Emergency Heat Cycle

If the compressor is inoperative due to a tripped safety device, the second stage of the thermostat automatically energizes the indoor-air fan and the electric resistance heat- ers (if equipped).

II. 575C090,120 UNITS

When power is supplied to unit, the transformer (TRAN) is energized. The crankcase heater is also energized.

A. Cooling

With the thermostat subbase in the cooling position, and when the space temperature comes within 2° F of the cooling set point, the thermostat makes circuit R-O. This energizes the reversing valve solenoid (RVS) and places the unit in standby condition for cooling.

As the space temperature continues to rise, the second stage of the thermostat makes, closing circuit R-Y. When compres- sor time delay (5 ± 2 minutes) is completed, a circuit is made to contactor (C), starting the compressor (COMP) and outdoor-fan motor (OFM). Circuit R-G is made at the same time, energizing the indoor-fan contactor (IFC) and starting the indoor-fan motor (IFM) after one-second delay.

—18—

541A, 575B, 575C specifications

The Bryant 575B, 541A, and 575C heating and cooling units are part of the renowned Bryant lineup, designed to provide efficient and reliable climate control solutions for residential and commercial spaces. These models are particularly celebrated for their impressive performance, innovative technologies, and user-friendly operations.

Starting with the Bryant 575B, this model is a high-efficiency air conditioner that boasts a SEER rating of up to 20.5. It utilizes a variable-speed compressor that adjusts its output based on the temperature needs of the home, leading to enhanced energy savings and consistent indoor comfort. The 575B is equipped with a steel cabinet that resists corrosion and damage while also minimizing noise levels during operation. Additionally, its environmentally friendly R-410A refrigerant helps to reduce the system's ecological footprint.

Moving on to the Bryant 541A, this unit is a formidable gas furnace known for its exceptional heating capabilities. With an AFUE (Annual Fuel Utilization Efficiency) rating of up to 97.5%, the 541A efficiently transforms fuel into heat, ensuring lower energy bills during cold months. It incorporates advanced technologies such as a two-stage gas valve and a variable-speed blower motor, allowing it to respond dynamically to the heating demands of the home. The insulated cabinet construction further enhances energy efficiency by preventing heat loss and increasing comfort.

Lastly, the Bryant 575C model is a versatile heat pump that offers both heating and cooling functionalities, ideal for regions with moderate heating and cooling needs. It features a SEER rating of up to 20 and an HSPF (Heating Season Performance Factor) rating of up to 10.5, making it an energy-efficient choice year-round. The 575C comes with a streamlined design that integrates a variable-speed compressor, which helps maintain precise temperatures and minimizes energy consumption. Additionally, its quiet operation is enhanced by sound insulation, providing a serene indoor environment.

All three models are designed with durability in mind, featuring robust construction materials that withstand the elements. They can be easily integrated with smart thermostats, providing homeowners with greater control over their energy use. With exceptional efficiency ratings, durable designs, and advanced features, the Bryant 575B, 541A, and 575C represent a perfect blend of comfort and cutting-edge technology. Whether for heating or cooling, these units deliver outstanding performance to meet the needs of today's energy-conscious consumers.