Carrier 38YCW Compressor Crankcase Heater, Install Electrical Accessories, Start-Up, Check Charge

NOTE: Install branch-circuit disconnect of adequate size per NEC to handle unit-starting current. Locate disconnect within sight from and readily accessible from unit, per Section 440-14 of NEC.

ROUTE GROUND AND POWER WIRES

Remove access panel and control box to gain access to unit wiring. Extend wires from disconnect through power-wiring hole provided and into unit-control box.

The unit cabinet must have an uninterrupted or unbroken ground to minimize personal injury if an electrical fault should occur. The ground may consist of electrical wire or metal conduit when installed in accordance with existing electrical codes. Failure to follow this warning can result in an electric shock, fire, or death.

CONNECT GROUND AND POWER WIRES

Connect ground wire to ground connection in control box for safety. Connect power wiring to contactor as shown in Fig. 5.

DISCONNECT

PER N.E.C. AND/OR

LOCAL CODES

CONTACTOR

FIELD POWER

WIRING

3 PHASE ONLY BLUE

FIELD GROUND

WIRING

GROUND

LUG

A94025

Fig. 5—Line Power Connections

CONNECT CONTROL WIRING

Route 24v control wires through control-wiring grommet and connect leads to control wiring. Refer also to Installation Instruc- tions packaged with thermostat.

Use No. 18 AWG color-coded, insulated (35°C minimum) wire. If thermostat is located more than 100 ft from unit, as measured along the control-voltage wires, use No. 16 AWG color-coded wire to avoid excessive voltage drop.

All wiring must be NEC Class 1 and must be separated from incoming power leads.

Use furnace transformer, fan-coil transformer, or accessory trans- former for control power, 24v/40va minimum.

NOTE: Use of available 24v accessories may exceed the mini- mum 40va power requirement. Determine total transformer load- ing and increase the transformer capacity or split the load with an accessory transformer as required.

FINAL WIRING CHECK

IMPORTANT: Check factory wiring and field-wire connections to ensure terminations are secured properly. Check wire routing to ensure wires are not in contact with tubing, sheet metal, and so forth.

Step 10—Compressor Crankcase Heater

When equipped with a crankcase heater, furnish power to heater a minimum of 24 hr before starting unit. To furnish power to heater

only, set thermostat to OFF and close electrical disconnect to outdoor unit. A crankcase heater is required if refrigerant tubing is longer than 50 ft.

Step 11—Install Electrical Accessories

Refer to the individual instructions packaged with kits or acces- sories when installing.

Step 12—Start-Up

To prevent compressor damage or personal injury, observe the following:

•Do not overcharge system with refrigerant.

•Do not operate unit in a vacuum or at negative pressure. •Do not disable low-pressure switch.

In scroll compressor applications: •Dome temperatures may be hot.

To prevent personal injury wear safety glasses, protective clothing, and gloves when handling refrigerant and observe the following:

•Back-seating service valves are not equipped with Schrader valves. Fully back seat (counterclockwise) valve stem before removing gage-port cap.

•Front-seating service valves are equipped with Schrader valves.

Do not vent refrigerant to atmosphere. Recover during system repair or final unit disposal.

If refrigerant tubes or indoor coil are exposed to atmosphere, they must be evacuated to 500 microns to eliminate contamination and moisture in the system.

Follow these steps to properly start up the system:

1.Fully back seat (open) liquid- and vapor-tube service valves.

2.Unit is shipped with valve stem(s) front seated (closed) and caps installed. Replace stem caps after system is opened to refrigerant flow. Replace caps finger-tight and tighten with wrench an additional 1/12 turn.

3.Close electrical disconnects to energize system.

4.Set room thermostat to desired temperature. Be sure set point is below indoor ambient temperature.

5.Set room thermostat to HEAT or COOL and fan control to ON or AUTO, as desired. Operate unit for a minimum of 15 minutes. Check system refrigerant charge.

•3-phase scroll compressors are rotation sensitive.

•A flashing LED on phase monitor indicates reverse rotation. (See Fig. 7 and Table 2.)

This will not allow contactor to be energized.

•Disconnect power to unit and interchange 2 field-wiring leads on unit contactor.

Step 13—Check Charge

Factory charge is shown on unit-rating plate. To check charge in cooling mode, refer to Cooling-Only Procedure on unit wiring and charging label.

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