Bryant 551A operation manual Physical Data

Table 1 — Physical Data

UNIT 551A		155		180	240
NOMINAL CAPACITY (tons)		12		15	20
OPERATING WEIGHT (lb)
Unit
Al/Al*		1575		1650	1750
Al/Cu*		1725		1800	1900
Cu/Cu*		1855		1930	2030
EconoMi$er		80		80	80
Roof Curb†		200		200	200
Perfect Humidity™ Dehumidification Package		40		40	40
COMPRESSOR
Quantity...Model (Ckt 1, Ckt 2)		1...ZR72KC, 1...ZR57KC		1...ZR94KC, 1...ZR72KC	1...ZR125KC, 1...ZR108KC
Number of Refrigerant Circuits		2		2	2
Crankcase Heater Watts		70		70	70
Loading (% of Full Capacity)		0, 56, 100		0, 60, 100	0, 60, 100
Oil (oz) (Ckt 1, Ckt 2)		60, 66		85, 60	110, 110
REFRIGERANT TYPE				R-22
Expansion Device				TXV
Operating Charge (lb)**
Circuit 1		20.7		19.5	18.5
Circuit 2		11.9		13.45	13.3
CONDENSER COIL		Cross-Hatched 3/ -in. Copper Tubes, Aluminum Lanced, Aluminum Pre-Coated,
			8
Rows...Fins/in.				or Copper Plate Fins
		4...15		4...15	4...15
Total Face Area (sq ft)		21.7		21.7	21.7
CONDENSER FAN				Propeller Type
Nominal Cfm		10,500		10,500	14,200
Quantity...Diameter (in.)		3...22		3...22	2...30
Motor Hp...Rpm		1/2...1050		1/2...1050	1...1075
Watts Input (Total)		1100		1100	3400
EVAPORATOR COIL		Cross-Hatched 3/ -in. Copper Tubes, Aluminum Lanced or Copper Plate Fins, Face Split
Rows...Fins/in.		8
		4...15		4...15	4...15
Total Face Area (sq ft)		17.5		17.5	17.5
EVAPORATOR FAN				Centrifugal Type
Quantity...Size (in.)		2...10 x 10		2...12 x 12	2...12 x 12
Type Drive		Belt		Belt	Belt
Nominal Cfm		5200		6000	8000
Std Motor Hp		2.9		5	7.5
Opt Motor Hp		3.7
Motor Nominal Rpm		1725		1745	1745
Std Maximum Continuous Bhp		3.13		6.13	9.47 [208 v], 10.33 [230 v and 460 v]
Opt Maximum Continuous Bhp		4.38		N/A	N/A
Motor Frame Size		56H		184T	213T
Fan Rpm Range	Low-Medium Static	834-1064		873-1021	1002 -1151
Motor Bearing Type	High Static	1161-1426		1025-1200	1193-1369
		Ball		Ball	Ball
Maximum Allowable Rpm		1,550		1,550	1,550
Motor Pulley Pitch Dia.	Low-Medium Static	3.1/4.1		4.9/5.9	5.4/6.6
	High Static	3.7/4.7		4.9/5.9	5.4/6.6
Nominal Motor Shaft Diameter (in.)	Low-Medium Static	7/8		11/8	13/8
Fan Pulley Pitch Diameter (in.)		6.0		9.4	9.4
	High Static	5.2		8.0	7.9
Nominal Fan Shaft Diameter (in.)	Low-Medium Static	13/16		17/16	17/16
Belt, Quantity...Type...Length (in.)		1...BX...42		1...BX...50	1...BX...54
Pulley Center Line Distance (in.)	High Static	1...BX...42		1...BX...48	1...BX...50
		13.5-15.5		13.3-14.8	14.6-15.4
Speed Change per Full Turn of Movable	Low-Medium Static	58		37	37
Pulley Flange (Rpm)	High Static	67		44	44
Movable Pulley Maximum Full Turns
From Closed Position		4††		4††	4††
Factory Speed		3.5		3.5	3.5
Factory Speed Setting (Rpm)	Low-Medium Static	978		965	1095
	High Static	1327		1134	1303
HIGH-PRESSURE SWITCH (psig)
Cutout			426
Reset (Auto.)			320
LOW-PRESSURE SWITCH (psig)
Cutout			27
Reset (Auto.)			44
FREEZE PROTECTION THERMOSTAT (F)
Opens			30 ± 5
Closes			45 ± 5
OUTDOOR-AIR INLET SCREENS				Cleanable
Quantity...Size (in.)				2...20 x 25 x 1
				1...20 x 20 x 1
RETURN-AIR FILTERS				Throwaway
Quantity...Size (in.)				4...20 x 20 x 2
				4...16 x 20 x 2

LEGEND

Al — Aluminum

Bhp — Brake Horsepower

Cu — Copper

TXV — Thermostatic Expansion Valve

*Evaporator coil fin material/condenser coil fin material. †Weight of 14-in. roof curb.

**Circuit 1 uses the lower portion of condenser coil and lower portion of evapora- tor coils, and Circuit 2 uses the upper portion of both coils.

††Due to belt and pulley style, pulley cannot be set from 0 to 11/2 turns open.

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