Bryant 548J manual Elec. Htr

Table 46 – MCA/MOCP DETERMINATION WITHOUT C.O. OR UNPWRD C.O.

	---HZ			ELEC. HTR					WITHOUT C.O. or UNPWR C.O.
UNIT	V---PH	IFM						WITHOUT P.E.					WITH P.E.
				Nom
		TYPE
						FLA			DISC. SIZE							DISC. SIZE
	NOM.60			(kW)
				---		---	30.7	45	30	121	32.6		50		32			123
							MCA	MOCP	FLA	LRA	MCA	MOCP			FLA			LRA
	---			3.3/4.4		15.9/18.3	50.6/53.6	60/60	48/51	137/139	52.5/55.5	60/60			51/53			139/141
	---1	DD---STD		4.9/6.5		23.5/27.1	60.1/64.6	70/70	57/61	145/148	62.0/66.5	70/70			59/63			147/150
	208/230			6.5/8.7		31.4/36.3	69.9/76.1	70/80	66/72	152/157	71.8/78.0	80/80			68/74			154/159
				7.9/10.5		37.9/43.8	78.1/85.4	80/90	74/81	159/165	80.0/87.3	80/90			76/83			161/167
				9.8/13.0		46.9/54.2	89.3/98.4	90/100	84/92	215/229	91.2/100.3	100/110			86/95			217/231
				---		---	24.8	30	25	97	26.7		30		27			99
				3.3/4.4		9.2/10.6	36.3/38.1	45/45	35/37	106/108	38.2/40.0	45/50			37/39			108/110
		DD---STD		4.9/6.5		13.6/15.6	41.8/44.3	50/50	40/43	111/113	43.7/46.2	50/50			43/45			113/115
				6.5/8.7		18.1/20.9	47.4/50.9	50/60	46/49	115/118	49.3/52.8	50/60			48/51			117/120
				7.9/10.5		21.9/25.3	52.2/56.4	60/60	50/54	119/122	54.1/58.3	60/60			52/56			121/124
	60			12.0/16.0		33.4/38.5	66.6/72.9	70/80	63/69	130/136	68.5/74.8	70/80			65/71			132/138
				---		---	22.6	30	22	109	24.5		30		24			111
	---			3.3/4.4		9.2/10.6	34.1/35.9	45/45	33/34	118/120	36.0/37.8	45/45			35/37			120/122
	---3	MED		4.9/6.5		13.6/15.6	39.6/42.1	45/50	38/40	123/125	41.5/44.0	50/50			40/42			125/127
	208/230			6.5/8.7		18.1/20.9	45.2/48.7	50/50	43/46	127/130	47.1/50.6	50/60			45/48			129/132
				7.9/10.5		21.9/25.3	50.0/54.2	50/60	47/51	131/134	51.9/56.1	60/60			50/53			133/136
				12.0/16.0		33.4/38.5	64.4/70.7	70/80	61/66	142/148	66.3/72.6	70/80			63/69			144/150
				---		---	22.6	30	22	120	24.5		30		24			122
548J*04				3.3/4.4		9.2/10.6	34.1/35.9	45/45	33/34	129/131	36.0/37.8	45/45			35/37			131/133
		HIGH		4.9/6.5		13.6/15.6	39.6/42.1	45/50	38/40	134/136	41.5/44.0	50/50			40/42			136/138
				6.5/8.7		18.1/20.9	45.2/48.7	50/50	43/46	138/141	47.1/50.6	50/60			45/48			140/143
				7.9/10.5		21.9/25.3	50.0/54.2	50/60	47/51	142/145	51.9/56.1	60/60			50/53			144/147
				12.0/16.0		33.4/38.5	64.4/70.7	70/80	61/66	153/159	66.3/72.6	70/80			63/69			155/161
				---		---	16.0	20	16	53	17.0		20		17			54
				6.0		7.2	25.0	30	24	60	26.0		30		26			61
		DD---STD		8.8		10.6	29.3	30	28	64	30.3		35		30			65
				11.5		13.8	33.3	35	32	67	34.3		35		33			68
				14.0		16.8	37.0	40	36	70	38.0		40		37			71
	---60			---		---	10.6	15	10	54	11.6		15		12			55
				6.0		7.2	19.6	20	19	61	20.6		25		20			62
	---3	MED		8.8		10.6	23.9	25	23	65	24.9		25		24			66
	460			11.5		13.8	27.9	30	26	68	28.9		30		27			69
				14.0		16.8	31.6	35	30	71	32.6		35		31			72
				---		---	10.6	15	10	60	11.6		15		12			61
				6.0		7.2	19.6	20	19	67	20.6		25		20			68
		HIGH		8.8		10.6	23.9	25	23	71	24.9		25		24			72
				11.5		13.8	27.9	30	26	74	28.9		30		27			75
				14.0		16.8	31.6	35	30	77	32.6		35		31			78
	60	DD---STD		---		---	5.4	15	5	5	7.4		15		7			7
	3---
		MED		---		---	3.4	15	3	8	5.4		15		5			10
	---
	575	HIGH		---		---	2.9	15	3	12	4.9		15		5			14
LEGEND									Example: Supply voltage is 230-3-60
C.O.		---	Convenient outlet							AB = 224V
DD		---	Electric Drive X13 Motor
										BC = 231V
DISC		---	Disconnect
										AC = 226V
FLA		---	Full load amps
IFM		---	Indoor fan motor								(224 + 231 + 226)						681
LRA		---	Locked rotor amps						Average Voltage =					=
											3						3
MCA		---	Minimum circuit amps
										=	227
MOCP		---	Maximum over current protection
									Determine maximum deviation from average voltage.
P.E.		---	Power exhaust
UNPWRD C.O. ---			Unpowered convenient outlet						(AB) 227 – 224 = 3V		Maximum deviation is 4V.
NOTES:									(BC) 231 – 227 = 4V		Determine percent of voltage imbalance.
1. In compliance with NEC requirements for multimotor and									% Voltage Imbalance		= 100 x		4
	combination load equipment (refer to NEC Articles 430 and
													227
	440), the overcurrent protective device for the unit shall be										= 1.76%
	fuse or HACR breaker. Canadian units may be fuse or cir-								This amount of phase imbalance is satisfactory as it is below the
	cuit breaker.
									maximum allowable 2%.
2. Unbalanced 3-Phase Supply Voltage
									IMPORTANT: If the supply voltage phase imbalance is more than
	Never operate a motor where a phase imbalance in supply								2%, contact your local electric utility company immediately.
	voltage is greater than 2%. Use the following formula to de-
	termine the percentage of voltage imbalance.
% Voltage Imbalance			= 100 x		max voltage deviation from average voltage
						average voltage

548J

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