Carrier 48MA/50ME016-040 specifications Ð Unit 48MA Electrical Data

Use the following formula to determine the percent volt- age imbalance.

% Voltage Imbalance:

= 100 ×	max voltage deviation from average voltage
	average voltage

EXAMPLE: Supply voltage is 460-3-60.

AB = 452 v

BC = 464 v

AC = 455 v

452 + 464 + 455

Average Voltage =

3

1371

=

3

= 457

Determine maximum deviation from average voltage.

(AB) 457 − 45 2 = 5 v (BC) 464 − 45 7 = 7 v (AC) 457 − 45 5 = 2 v

Maximum deviation is 7 v.

Determine percent voltage imbalance:

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

Unit failure as a result of operation on improper line volt- age or excessive phase imbalance constitutes abuse and may cause damage to electrical components. See Tables 2-5 for unit, electric heater, and 50ME electrical application elec- trical data.

Each 50ME electric heat unit is ®tted with a heating lock- out circuit (if equipped with optional heat). If any zone mod- ule is operating on mechanical cooling (compressor is op- erating), the heating element in each zone module is locked out and cannot be energized.

On 50ME units, cooling power supply wires and electric heater power supply wires (if applicable) must be sized ac- cording to the cooling MCA (Minimum Circuit Amps) val- ues and heating MCA values shown on unit nameplate and in Tables 3-5. These wires may be powered by a common power supply (i.e., a pull-box junction), if desired. The com- mon power supply wires from the main power source to the junction must be sized according to the common MCA val- ues shown in Table 5.

% Voltage Imbalance = 100 x

7

UNIT COMMON FEED MINIMUM CIRCUIT AMPS Ð The unit common feed MCA is calculated on the basis of

457

= 1.53%

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

either: the sum of the cooling MCA plus 1¤2 heating MCA on units with 2 heating elements per zone module (or 2¤3 heat- ing MCA on units with 3 heating elements per zone module) or the sum of the evaporator fan motor full load amps, per NEC, plus the full heating MCA, whichever is larger. Field wiring must conform to NEC limitations for Type T wire.

Table 2 Ð Unit 48MA Electrical Data

UNIT	Voltage	VOLTAGE		COMP		COMP			OFM		COMBUSTION		IFM		POWER
		RANGE		NO. 1		NO. 2			FLA		FAN MOTOR				SUPPLY
48MA	(3 Ph, 60 Hz)
		Min	Max	RLA	LRA	RLA	LRA	No. 1	No. 2	No. 3	FLA	Hp		FLA	MCA	MOCP
	208/230	187	254	63.6	266				6.6					16.2	109.6	125
016	460	414	508	28.6	120	Ð	Ð	6.2	3.0	Ð	1.8	5		6.6	49.8	60
	575	518	632	22.8	96				2.4					5.6	39.8	45
	208/230	187	254	44.4	170	44.4	170		6.6					24.2	137.5	150
024	460	414	508	19.9	77	19.9	77	6.2	3.0	Ð	1.8	7.5		11.0	62.2	70
	575	518	632	15.7	62	15.7	62		2.4					9.0	49.4	60
	208/230	187	254	63.6	266	44.4	170		6.6					30.8	168.1	200
028	460	414	508	28.6	120	19.9	77	6.2	3.0	Ð	1.8	10		13.0	76.1	90
	575	518	632	22.8	96	15.7	62		2.4					10.5	60.4	70
	208/230	187	254	63.6	266	63.6	266		6.6					30.8	187.3	200
030	460	414	508	28.6	120	28.6	120	6.2	3.0	Ð	1.8	10		13.0	84.5	100
	575	518	632	22.8	96	22.8	96		2.4					10.5	67.5	90
	208/230	187	254	63.6	266	63.6	266		6.6	6.6		15		46.2	210.8	225
												20		61.0	224.6	250
034	460	414	508	28.6	120	28.6	120	6.2	3.0	3.0	1.8	15		21.0	94.5	100
												20		26.6	100.5	125
	575	518	632	22.8	96	22.8	96		2.4	2.4		15		16.0	75.6	90
												20		21.3	80.6	100
	208/230	187	254	80.0	345	80.0	345		6.6	6.6		15		46.2	247.7	300
												20		61.0	261.5	300
040	460	414	508	38.5	150	38.5	150	6.2	3.0	3.0	1.8	15		21.0	116.7	150
												20		27.0	122.7	150
	575	518	632	31.4	120	31.4	120		2.4	2.4		15		16.0	95	125
												20		21.3	100	125

	LEGEND
COMP Ð Compressor
FLA	Ð Full Load Amps
IFM	Ð Indoor (Evaporator) Fan Motor
LRA	Ð Locked Rotor Amps
MCA	Ð Minimum Circuit Amps

MOCP Ð Maximum Overcurrent Protection

OFM	Ð	Outdoor (Condenser) Fan Motor
RLA	Ð	Rated Load Amps

NOTES:

1.Combustion air fan is a 115-1-60 motor on all units.

2.Condenser fan motor no. 1 is a 208/230-1-60 speed control motor on all units.

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