Carrier 48EZ(N)-A Install Electrical Connections, High-VoltageConnections, 48EZ --A

Step 10 — Install Electrical Connections

!WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury or death.

The unit cabinet must have an uninterrupted, unbroken

HIGH VOLTAGE POWER LEADS (SEE UNIT WIRING LABEL)

EQUIP GR

CONTROL BOX

POWER

SUPPLY

FIELD-SUPPLIED FUSED DISCONNECT

electrical ground. This ground may consist of an electrical wire connected to the unit ground screw in the control compartment, or conduit approved for electrical ground when installed in accordance with NEC, NFPA 70 National Fire Protection Association (latest edition) (in Canada, Canadian Electrical Code CSA C22.1) and local electrical codes.

!CAUTION

UNIT COMPONENT DAMAGE HAZARD

LOW-VOLTAGE POWER LEADS (SEE UNIT WIRING LABEL)

SPLICE BOX

WHT(W1)	W
YEL(Y)	Y
GRN(G)	G
RED(R)	R
BRN(C)	C
ORN(O)	O
BLU (DH)	DH
GRA (Y2)	3-Phase
	Only

THERMOSTAT (TYPICAL)

48EZ -- A

Failure to follow this caution may result in damage to the unit being installed.

1.Make all electrical connections in accordance with NEC NFPA 70 (latest edition) and local electrical codes governing such wiring. In Canada, all electrical connections must be in accordance with CSA standard C22.1 Canadian Electrical Code Part 1 and applicable local codes. Refer to unit wiring diagram.

2.Use only copper conductor for connections between field-supplied electrical disconnect switch and unit. DO NOT USE ALUMINUM WIRE.

3.Be sure that high-voltage power to unit is within operating voltage range indicated on unit rating plate. On 3-phase units, ensure phases are balanced within 2 percent. Consult local power company for correction of improper voltage and/or phase imbalance.

4.Insulate low-voltage wires for highest voltage contained within conduit when low-voltage control wires are in same conduit as high-voltage wires.

5.Do not damage internal components when drilling through any panel to mount electrical hardware, conduit, etc.

High-Voltage Connections

When routing power leads into unit, use only copper wire between disconnect and unit. The high voltage leads should be in a conduit until they enter the duct panel; conduit termination at the duct panel must be watertight.

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

The field-supplied disconnect switch box may be mounted on the unit over the high-voltage inlet hole when the standard power and low-voltage entry points are used (See Fig. 2 and 3 for acceptable location).

NOTE: Field supplied disconnect switch box should be positioned so that it does not cover up any of the unit gas combustion supply air louvers.

See unit wiring label (Fig. 14 and 15) and Fig. 9 for reference when making high voltage connections. Proceed as follows to complete the high-voltage connections to the unit.

Single phase units:

1.Run the high-voltage (L1, L2) and ground lead into the control box.

2.Connect ground lead to chassis ground connection.

A09067

Fig. 9 - High and Control-Voltage Connections

3.Locate the black and yellow wires connected to the line side of the contactor.

4.Connect field L1 to black wire on connection 11 of the compressor contactor.

5.Connect field wire L2 to yellow wire on connection 23 of the compressor contactor.

Three-phase units:

1.Run the high-voltage (L1, L2, L3) and ground lead into the control box.

2.Connect ground lead to chassis ground connection.

3.Locate the black and yellow wires connected to the line side of the contactor.

4.Connect field L1 to black wire on connection 11 of the compressor contactor.

5.Connect field wire L3 to yellow wire on connection 13 of the compressor contactor.

6.Connect field wire L2 to blue wire from compressor.

Special Procedures for 208-V Operation

!WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury or death.

Make sure the power supply to the unit is switched OFF before making any wiring changes. Tag the disconnect switch with a suitable warning label. With disconnect switch open, move black wire from transformer (3/16 in.) terminal marked 230 to terminal marked 200. This retaps transformer to primary voltage of 208 vac.

!WARNING

ELECTRICAL SHOCK AND EXPLOSION HAZARD

Failure to follow this warning could result in personal injury or death.

Before making any wiring changes, make sure the gas supply is switched off first. Then switch off the power supply to the unit and install lockout tag.

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