Emerson Figure i manual Electrical Connections, Low-Voltage Control Wire Connections

Installation

2.6Electrical Connections

Each unit is shipped from the factory with all internal wiring completed. All power, control wiring and ground connections must be made in accordance with the National Electrical Code and local codes. Refer to equipment nameplate regarding wire size and circuit protection requirements. Refer to Figures 5, 7 and 8 and electrical schematic (reference Figures 9 through 11) when making connec- tions. A manual electrical disconnect switch should be installed within 5 feet (1.6 m) of the unit in accordance with codes.

! WARNING

Use voltmeter to be sure power is turned off before making any electrical connections.

! CAUTION

Three-phase power must be connected to the unit line voltage terminals in proper sequence so that scroll compressor rotates in the correct direction.

The three-phase scroll compressor requires proper phasing to ensure correct motor rotation. The com- ponent connections have been phase synchronized at the factory. Power phasing should be changed only at the line voltage supply to the unit. To change phasing, switch any two power leads to the unit. Observe system pressures to determine whether the unit is operating properly.

! CAUTION

Apply power to condenser 8 hours before operating system. This time is required to allow liquid refrigerant to be driven out of the compressor. This is especially important at low ambient temperatures. The compressor crankcase heater is energized as long as power is supplied to the unit.

Table 13 Design refrigerant pressures

Suction	53 - 95 PSIG
	(365 to 655 kPa)
Discharge	280 psig (1930 kPa)
(At Design Ambient)
High Pressure Cutout	400 psig (2760 kPa)

Table 14 Application limits

Input voltage		Dry Bulb Air Temperature at Condenser
Minimum	Maximum	Minimum	Maximum
-10%			115°F (46°C) Std
			Ambient & Quiet-Line
	+10%	-30°F (-34°C)
-5% 208/230V			125°F (52°C)
single-phase			High Ambient Models

2.6.1Low-Voltage Control Wire Connections

Field-supplied four-wire control connection (10-wire on 8-ton units) is required between the outdoor condensing unit and the evaporator. Refer to Figures 5, 7 and 8 and to unit electrical schematic and Figures 9 through 11.

2.6.2Low-Voltage Control Wire Sizing

Low-voltage wiring should be sized to allow a 1 volt maximum drop due to line resistance between the evaporator and condensing unit. Use NEC Class 1 or 2 wiring according to wire routing conditions chosen, local codes and application limits in Tables 14 and 15.

Table 15 Recommended minimum wire size

Max. Distance*	Min. Wire Gauge
ft. (m)	AWG (mm2)
50 (15)	20 (0.75)
100 (30)	18 (1.0)
150 (45)	16 (1.5)

*One-way control wire run between outdoor condensing unit and evaporator.

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