Carrier 38AU Unit Wire/Fuse or Hacr Breaker Sizing Data, Unbalanced 3-Phase Supply Voltage

38AU

Table 10 – Unit Wire/Fuse or HACR Breaker Sizing Data

	NOMINAL	VOLTAGE			COMPRESSOR						NO C.O. or UNPWRD C.O.
	POWER
UNIT		RANGE		No. 1		No. 2			OFM		POWER SUPPLY		DISCONNECT SIZE
	SUPPLY
SIZE
38AU										FLA		FUSE or
	V---Ph---Hz	Min	Max	RLA	LRA	RLA	LRA	Qty			MCA	HACR	FLA	LRA
										(ea)
												BRKR
	208/230---3---60	187	253	25.0	164	25.0	164	3		1.5	60.8/60.8	80/80	63/63	337/337
D*16
	460---3---60	414	506	12.2	100	12.2	100	3		0.8	29.9	40	31	206
Z*16
	575---3---60	518	633	9.0	78	9.0	78	3		0.7	22.4	30	23	162
	208/230---3---60	187	253	30.1	225	30.1	225	4		1.5	73.7/73.7	100/100	76/76	462/462
D*25
	460---3---60	414	506	16.7	114	16.7	114	4		0.8	40.8	50	42	236
Z*25
	575---3---60	518	633	12.2	80	12.2	80	4		0.7	30.3	40	31	168
	NOMINAL	VOLTAGE			COMPRESSOR						w/ PWRD C.O.
	POWER
UNIT		RANGE		No. 1		No. 2			OFM		POWER SUPPLY		DISCONNECT SIZE
	SUPPLY
SIZE
38AU										FLA		FUSE or
	V---Ph---Hz	Min	Max	RLA	LRA	RLA	LRA	Qty			MCA	HACR	FLA	LRA
										(ea)
												BRKR
	208/230---3---60	187	253	25.0	164	25.0	164	3		1.5	65.6/65.6	90/90	68/68	342/342
D*16
	460---3---60	414	506	12.2	100	12.2	100	3		0.8	32.1	40	33	208
Z*16
	575---3---60	518	633	9.0	78	9.0	78	3		0.7	24.1	30	25	164
	208/230---3---60	187	253	30.1	225	30.1	225	4		1.5	78.5/78.5	100/100	82/82	467/467
D*25
	460---3---60	414	506	16.7	114	16.7	114	4		0.8	43	50	45	238
Z*25
	575---3---60	518	633	12.2	80	12.2	80	4		0.7	32	40	33	170

Legend and Notes for Table 10

LEGEND:
BRKR	---	Circuit breaker
CO	---	Convenient outlet
FLA	---	Full Load Amps
LRA	---	Locked Rotor Amps
MCA	---	Minimum Circuit Amps
		Protection
NEC	---	National Electrical Code
PWRD CO	---	Powered convenient outlet
RLA	---	Rated Load Amps
UNPWR 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.The MCA values are calculated in accordance with The NEC. Article 440.

3.Motor RLA and LRA values are established in accordance with Underwriters’ Laboratories (UL). Standard 1995.

4.The 575--- v units are UL, Canada--- listed only.

5.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.

Example: Supply voltage is 230-3-60

% Voltage Imbalance = 100 x	max voltage deviation from average voltage
	average voltage

AB = 224 v

BC = 231 v

AC = 226 v

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

% Voltage Imbalance	= 100 x	4
		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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