Carrier 38CKC(Q) instruction manual ÐCompressor Crankcase Heater, ÐInstall Electrical Accessories

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

Step 9ÐCompressor 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.

NOTE: The Seasonal Energy Efficiency Ratio (SEER) is ob- tained with crankcase heater de-energized. To de-energize crank- case heater, disconnect black crankcase heater wires at contactor. After disconnecting, make sure wires are isolated from all other electrical connections and components to prevent electrical short- ing.

Step 10ÐInstall Electrical Accessories

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

Step 11ÐStart-Up and Check Charge

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.

·In 3 phase application, incorrect phasing will cause reverse rotation, resulting in elevated noise levels, equalized pres- sures, and reduced current draw. Correct by reversing power connection L1 and L2 on contactor.

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 (counter clockwise) 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.

Follow these steps to properly pumpdown a system and avoid negative suction pressure.

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 1/6-turn for front seating valves (female hex stem) or 1/12 turn for back seating valves (male square stem).

3.Close electrical disconnects to energize system.

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

5.Set room thermostat to COOL and fan to FAN or AUTO mode, as desired. Operate unit for 15 minutes. Check system refrigerant charge.

6.Factory charge is shown on unit rating plate. Adjust charge by following procedure shown on charging tables located on unit.

SEQUENCE OF OPERATION

Turn on power to indoor and outdoor units. Transformer is energized.

On a call for cooling, thermostat makes circuits R-Y and R-G. Circuit R-Y energizes contactor, starting outdoor fan motor and compressor circuit. R-G energizes indoor unit blower relay, starting indoor blower motor on high speed.

When thermostat is satisfied, its contacts open, de-energizing contactor and blower relay. Compressor and motors stop.

If indoor unit is equipped with a time-delay relay circuit, the indoor blower will run an additional 90 sec to increase system efficiency.

CARE AND MAINTENANCE

For continued high performance and to minimize possible equip- ment failure, periodic maintenance must be performed on this equipment.

Leave User's Manual with homeowner. Explain system operation and periodic maintenance requirements outlined in manual. Fre- quency of maintenance may vary depending on geographic areas, such as coastal applications which require more frequent mainte- nance.

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