Bryant 549B, 542J, 548F manual Application Data

CONTROLS (cont)

LEGEND

AHA	— Adjustable Heat Anticipator	IFR	—	Indoor-Fan Relay	Terminal (Marked)
CB	— Circuit Breaker	L	—	Light
CC	— Cooling Compensator	LLS	—	Liquid Line Solenoid	Terminal (Unmarked)
CLO	— Compressor Lockout	OAT	—	Outdoor-Air Thermostat	Terminal Block
DAT	— Discharge Air Thermistor	PL	—	Plug Assembly
DM	— Damper Motor	SR	—	Solenoid Relay	Splice
EAS	— Economizer Actuator	TB	—	Terminal Block
	Auxiliary Switch	TC	—	Thermostat Cooling	Factory Wiring
EMC	— Economizer Motor Contactor	TH	—	Thermostat Heating	Field Wiring
FU	— Fuse	TRAN —		Transformer
					Option/Accessory Wiring
IFC	— Indoor-Fan Contactor	UR	—	Unloader Relay

To Indicate Common Potential

Only, Not To Represent Wiring

APPLICATION DATA

1.OUTDOOR INSTALLATION — Units approved for outdoor installation only.

2.DUCTWORK — Secure vertical discharge ductwork to roof curb. For horizontal discharge applications, either attach ductwork to unit, or use field-supplied flanges attached to the horizontal discharge openings and attach all ductwork to flanges.

3.HORIZONTAL ECONOMI$ER — A field-installed acces- sory for horizontal discharge applications. Field-installed power exhaust accessory also available for vertical or hori- zontal EconoMi$er applications (036-120).

4.THRU-THE-BOTTOM POWER CONNECTIONS — For applications requiring thru-the-bottom connections, Bryant accessory thru-the-bottom package must be purchased to ensure proper connections (036-120).

5.THERMOSTAT — Use of 2-stage heating and cooling ther- mostat is recommended for all units. A 2-stage cooling ther- mostat is required on units with accessory economizer to provide integrated cooling. A two-stage thermostat is required for all 548F/549B090,120 and 542J150,180 units.

6.HEATING-TO-COOLING — All units are automatic changeover from heating to cooling when automatic changeover thermostat and subbase are used.

7.AIRFLOW — Units are draw-thru on cooling and blow-thru on heating.

8.MAXIMUM AIRFLOW — To minimize the possibility of con- densate blow-off from indoor coil, airflow through units should not exceed 500 cfm/ton.

9.MINIMUM AIRFLOW — For cooling, minimum airflow is 300 cfm/ton. For 548F units with electric heating, the required minimum cfm is 900 for 548F036; 1200 for 548F048; 1500 for 548F060; 1800 for 548F072; 2250 for 548F090; 2500 for 548F102; and 3000 for 548F120, with the following exceptions:

UNIT	UNIT	HEATER	UNIT	REQUIRED
				MINIMUM
548F	VOLTAGE	kW	CONFIGURATION
				CFM
	208/230	42.4	Horizontal	3200
120	208/230	50.0	Horizontal	3200
			Horizontal
	460	50.0	or	3200
			Vertical
090-120		17.0	Horizontal	2800
	575		or
		34.0		2350
			Vertical

For 549B and 542J units with electric heating, the required minimum cfm is 900 for 549B036; 1200 for 549B048; 1500 for 549B060; 1700 for 549B072; 2250 for 549B090; 3000 for 549B120; 3900 for 542J150; and 4500 for 542J180, with the fol- lowing exceptions:

UNIT	UNIT	HEATER	UNIT	REQUIRED
				MINIMUM
549B	VOLTAGE	kW	CONFIGURATION
				CFM
			Horizontal
	208/230	50.0	or	3250
120			Vertical
			Horizontal
	460	50.0	or	3400
			Vertical

10.MINIMUM AMBIENT COOLING OPERATING TEMPERA- TURE — The minimum temperature for standard units is 25 F (036-120) and 40 F (542J150,180). With accessory Motormaster® control, units can operate at outdoor temper- atures down to –20 F.

11.INTERNAL UNIT DESIGN — Due to Bryant’s internal unit design (draw-thru over the motor), air path, and specially designed motors, the full horsepower (maximum continuous bhp) listed in the Physical Data table and the notes following each Fan Performance table can be utilized with confidence.

Using Bryant motors with the values listed in the Physical and Fan Performance Data tables will not result in nuisance tripping or premature motor failure. The unit warranty will not be affected.

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