Bryant 581B installation instructions High-VoltageConnections Fig

High-Voltage Connections (Fig. 13)

The unit must have a separate electrical service with a ®eld- supplied, waterproof, fused disconnect switch mounted at, or within sight from the unit. Refer to the unit rating plate for maximum fuse/circuit breaker size and minimum circuit amps (ampacity) for wire sizing.

The ®eld-supplied disconnect switch box may be mounted on the unit over the high-voltage inlet hole in the control corner panel.

Proceed as follows to complete the high-voltage connections to the unit:

1.Connect ground lead to chassis ground connection when using separate ground wire.

2.Pigtails are provided for ®eld power connection. Use factory-supplied splices or UL (Underwriters'

Laboratories) approved copper connector. Install con- duit connectors in side panel power supply knockout openings indicated in Fig. 2. Route power lines through connector to unit control box.

Special Procedures for 208-V Operation

DANGER: Make sure that the power supply to the unit is switched OFF before making any wiring changes. Electrical shock can cause personal injury or death.

For operation on 208 v, disconnect the black wire from the 230-v orange wire on the transformer and connect it to the 200-v red wire from the transformer. Insulate the end of the orange wire.

Table 3A Ð Electrical Data (Units Without Electrical Convenience Outlet)

	NOMINAL	VOLTAGE						COMBUSTION			MINIMUM UNIT
UNIT				COMPRESSOR		OFM	IFM		POWER SUPPLY		DISCONNECT
	VOLTAGE	RANGE						FAN MOTOR
581B												SIZE*
	(V-Ph-Hz)
		Min	Max	RLA	LRA	FLA	FLA	FLA	MCA	MOCP²	FLA		LRA
	208/230-1-60	187	254	16.0	88.0	0.7	4.9	.57	25.6/25.6	35/35	25/25		101/101
036	208/230-3-60	187	254	10.3	77.0	0.7	4.9	.57	18.5/18.5	25/25	18/18		90/ 90
(3 Tons)	460-3-60	414	508	5.1	39.0	0.4	2.2	.30	9.0	15	9		46
	575-3-60	518	632	4.2	31.0	0.4	2.2	.30	7.3	15	7		37
	208/230-1-60	187	254	23.7	129.0	0.7	4.9	.57	35.2/35.2	45/45	34/34		142/142
048	208/230-3-60	187	254	13.5	99.0	0.7	4.9	.57	22.5/22.5	30/30	22/22		112/112
(4 Tons)	460-3-60	414	508	7.4	49.5	0.4	2.2	.30	9.7	15	12		57
	575-3-60	518	632	5.8	40.0	0.4	2.2	.30	9.3	15	9		46
	208/230-1-60	187	254	28.8	169.0	1.5	8.8	.57	46.3/46.3	60/60	45/45		216/216
060	208/230-3-60	187	254	17.3	123.0	1.5	5.8	.57	29.0/29.0	35/35	28/28		168/168
(5 Tons)	460-3-60	414	508	9.0	62.0	0.8	2.6	.30	14.7	20	14		84
	575-3-60	518	632	7.1	50.0	0.8	2.6	.30	11.6	15	11		59
072	208/230-3-60	187	254	20.5	156.0	1.4	5.8	.57	32.8/32.8	40/40	32/32		200/200
	460-3-60	414	508	9.6	70.0	0.6	2.6	.30	15.2	20	15		92
(6 Tons)
	575-3-60	518	632	7.7	56.0	0.6	2.6	.30	12.2	15	12		74

	LEGEND
FLA	Ð Full Load Amps
HACR	Ð Heating, Air Conditioning and Refrigeration
IFM	Ð Indoor (Evaporator) Fan Motor
LRA	Ð Locked Rotor Amps
MCA	Ð Minimum Circuit Amps
MOCP Ð Maximum Overcurrent Protection
NEC	Ð National Electrical Code
OFM	Ð Outdoor (Condenser) Fan Motor
RLA	Ð Rated Load Amps
UL	Ð Underwriters' Laboratories

*Used to determine minimum disconnect per NEC. ²Fuse or HACR circuit breaker.

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 ± 452 = 5 v

(BC) 464 ± 457 = 7 v

(AC) 457 ± 455 = 2 v Maximum deviation is 7 v.

Determine percentage of voltage imbalance:

% Voltage Imbalance = 100 x

7

NOTES:

1.In compliance with NEC requirements for multimotor and combina- tion load equipment (refer to NEC Articles 430 and 440), the over- current protective device for the unit shall be fuse or HACR breaker. The CUL 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 determine the percent- age of voltage imbalance.

max voltage deviation

%Voltage Imbalance = 100 x from average voltage average voltage

457

= 1.53%

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.

3. 575-v units are UL, Canada approved only.

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