Carrier 50VL---A SPECIAL PROCEDURES FOR 208-VOPERATION, Control Voltage Connections, 50VL--A

50VL-- A

							SPECIAL PROCEDURES FOR 208-V OPERATION
	(SEE UNIT WIRING					SUPPLY			WARNING
	HIGH VOLTAGE						!
	POWER LEADS					POWER
	LABEL)
	3-PHASE SHOWN							ELECTRICAL SHOCK HAZARD
	1-PHASE USES							Failure to follow this warning could result in personal
	TWO POWER
			EQUIP GR					injury or death.
	LEADS
				FIELD-SUPPLIED
								Before installing or servicing system, always turn off main
				FUSED DISCONNECT
	CONTROL BOX							power to system and install lockout tag. With disconnect
								switch open, move black wire from transformer (3/16
				WHT(W1)
					W1			in.)(4.8 mm) terminal marked 230 to terminal marked 208.
				VIO (W2)
					W2			This retaps transformer to primary voltage of 208 vac.
				YEL(Y)
					Y
LOW-VOLTAGE				GRN(G)	G		CONTROL VOLTAGE CONNECTIONS
				RED(R)		THERMOSTAT NOTE: Do not use any type of power-stealing thermostat. Unit
POWER LEADS					R
(SEE UNIT				BRN(C)		(TYPICAL)	control problems may result.
WIRING LABEL)					C		Use no. 18 American Wire Gage (AWG) color-coded, insulated
				BLU (DH)
					DH		(35°C minimum) wires to make the control voltage connections
				GRA (Y2)
					3-Phase		between the thermostat and the unit. If the thermostat is located
					Only		more than 100 ft (30.5 m) from the unit (as measured along the
		SPLICE BOX					control voltage wires), use no. 16 AWG color-coded, insulated
							(35° C minimum) wires.
						A09066
							STANDARD CONNECTION
	Fig. 10 - High- and Control-Voltage Connections
							Locate the seven (eight for 3-phase) low voltage thermostat leads
	5. Connect field wire L2 to yellow wire on connection 23 of						in 24 volt splice box. A gray wire is standard on 3-phase units for
	the compressor contactor.						connection to an economizer. See Fig. 10 for connection diagram.
Three-phase units:							Run the low-voltage leads from the thermostat, through the control
							wiring inlet hole grommet (Fig. 2 and 3), and into the low-voltage
	1. Run the high-voltage (L1, L2, L3) and ground lead into the
							splice box. Provide a drip loop before running wires through panel.
	control box.
							Secure and strain relief all wires so that they do not interfere with
	2. Connect ground lead to chassis ground connection.
							operation of unit.
	3. Locate the black and yellow wires connected to the line side
							If an accessory electric heater is installed, low voltage leads from
	of the contactor.
							heater must be connected to factory supplied control leads from
	4. Connect field L1 to black wire on connection 11 of the
							Indoor Fan Board P4 connector.
	compressor contactor.						NOTE: If the unit 24V wires do not have a matching receptacle,
	5. Connect field wire L3 to yellow wire on connection 13 of
							cut the 24V wires from the electric heater plug, strip the ends, and
	the compressor contactor.						wire nut together to match the schematic connections. If the electric
	6. Connect field wire L2 to blue wire from compressor.						heater 24V wires do not have a matching plug, cut the 24V wires
							from the unit receptacle, strip the ends, and wire nut together to
							match the schematic connections.

Factory wires are provided for electric heat staging W1 and W2 (W2 and W3 on IFB). If room thermostat has only one stage of supplemental heat, connect white and violet wires shown in Fig. 10 to second stage heat field wire.

Some electric heaters have four control wires (plus common wire). Consult unit wiring diagram and electric heater wiring diagram for additional details.

TRANSFORMER PROTECTION

The transformer is of the energy-limiting type, however a direct short will likely blow a secondary fuse. If an overload or short is present, correct overload condition and check for blower fuse on Indoor Fan Board. Replace fuse as required with correct size and rating.

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