Bryant 580J*04--12 appendix Nom, Unbalanced 3-Phase Supply Voltage

APPENDIX IV. ELECTRICAL DATA (cont.)

MCA/MOCP DETERMINATION NO C.O. OR UNPWRD C.O.

			COMBUSTION	POWER	NO C.O. or UNPWRD C.O.					NO C.O. or UNPWRD C.O.
UNIT	NOM.	IFM					NO P.E.				w/ P.E. (pwrd fr/ unit)
			FAN MOTOR	EXHAUST
	V---Ph---Hz	TYPE						DISC. SIZE					DISC. SIZE
			FLA	FLA	MCA	MOCP				MCA		MOCP
								FLA	LRA				FLA	LRA
		STD			39.5	60		38	191	43.3		60	43	195
	208/230--- 3--- 60	MED	0.48	3.8	41.8	60		41	228	45.6		60	45	232
		HIGH			49.3	60		49	254	53.1		60	54	258
580J*08
		STD			19.5	30		19	113	21.3		30	21	115
		HIGH			24.3	30		24	145	26.1		30	26	147
	460--- 3--- 60	MED	0.25	1.8	20.3	30		20	132	22.1		30	22	134
		STD			14.9	20		14	89	18.7		25	19	93
	575--- 3--- 60	MED	0.24	3.8	15.3	20		15	104	19.1		25	19	108
		HIGH			18.1	25		18	118	21.9		30	23	122
		STD			45.1	60		43	222	48.9		60	48	226
	208/230--- 3--- 60	MED	0.48	3.8	45.1	60		43	233	48.9		60	48	237
		HIGH			49.9	60		49	276	53.7		80	53	280
580J*09
		STD			22.6	30		22	108	24.4		30	24	110
		HIGH			24.4	30		24	136	26.2		30	26	138
	460--- 3--- 60	MED	0.25	1.8	22.6	30		22	114	24.4		30	24	116
		STD			18.9	30		18	91	22.7		30	23	95
	575--- 3--- 60	MED	0.24	3.8	18.5	30		18	95	22.3		30	22	99
		HIGH			19.3	30		19	106	23.1		30	23	110
		STD			45.8	60		44	263	49.6		60	48	267
	208/230--- 3--- 60	MED	0.48	3.8	50.6	60		50	306	54.4		80	54	310
		HIGH			55.6	80		55	315	59.4		80	60	319
580J*12
		STD			25.1	30		24	133	26.9		40	26	135
		HIGH			29.9	45		30	159	31.7		45	32	161
	460--- 3--- 60	MED	0.25	1.8	26.9	40		26	155	28.7		45	28	157
		STD			18.5	30		18	95	22.3		30	22	99
	575--- 3--- 60	MED	0.24	3.8	19.3	30		19	106	23.1		30	23	110
		HIGH			22.1	30		22	120	25.9		30	26	124

580J

1Fuse or breaker

LEGEND:
CO	---	Convenient outlet
DISC	---	Disconnect
FLA	---	Full load amps
IFM	---	Indoor fan motor
LRA	---	Locked rotor amps
MCA	---	Minimum circuit amps
MOCP	--- Maximum over current protection
PE	---	Power exhaust
UNPWRD CO	---	Unpowered convenient outlet
NOTES:

1.In compliance with NEC requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the overcurrent protective device for the unit shall be fuse or HACR breaker. Canadian units may be fuse or circuit breaker.

2.Unbalanced 3-Phase Supply Voltage

Never operate a motor where a phase imbalance in supply 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

Example: Supply voltage is 230-3-60

AB = 224 v

BC = 231 v

AC = 226 v

(224 + 231 + 226)	681
Average Voltage =	=
3	3

=227

Determine maximum deviation from average voltage. (AB) 227 – 224 = 3 v

(BC) 231 – 227 = 4 v (AC) 227 – 226 = 1 v Maximum deviation is 4 v.

Determine percent of voltage imbalance.

	4
% Voltage Imbalance	= 100 x
	227
	= 1.76%

This amount of phase imbalance is satisfactory as it is below the maximum allowable 2%.

IMPORTANT: If the supply voltage phase imbalance is more than 2%, contact your local electric utility company immediately.

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