Table 2—Accessory Usage
| REQUIRED FOR | REQUIRED FOR | REQUIRED FOR | |
ACCESSORY | BURIED LINE | |||
APPLICATIONS | APPLICATIONS* | APPLICATIONS† | ||
| ||||
| (BELOW 55°F) | (OVER 50 FT) | (OVER 3 FT) | |
Crankcase Heater | Yes | Yes | Yes | |
Evaporator Freeze Thermostat | Yes | No | No | |
Accumulator | No | No | Yes | |
Compressor | Yes | Yes | Yes | |
Capacitor and Relay | ||||
|
|
| ||
MotorMaster® Control, |
|
|
| |
or | Yes | No | No | |
|
|
| ||
Wind Baffle | See | No | No | |
Instructions | ||||
|
|
| ||
Unit Risers | Recommended | No | No | |
| See |
| ||
or | No | Application | Yes | |
| Guideline |
| ||
Yes‡ | No | No | ||
|
|
|
|
*For tubing line sets between 50 and 175 ft, refer to Application Guideline and Service Manual — Air Conditioners and Heat Pumps.
† For buried line applications, refer to Application Guideline and Service Manual — Air Conditioners and Heat Pumps.
‡ Required for
DISCONNECT
PER N. E. C. AND/OR LOCAL CODES
FIELD POWER
WIRING
FIELD GROUND
WIRING
CONTACTOR
GROUND
LUG
A91056
Step 13—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
In scroll compressor applications: •Dome temperatures may be hot.
Fig. 8—Line Power Connections
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.
IMPORTANT: Check factory wiring and 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 11—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 12—Install Electrical Accessories
Refer to the individual instructions packaged with kits or acces- sories when installing.
To prevent personal injury wear safety glasses, protective clothing, and gloves when handling refrigerant and observe the following:
Federal Regulations require that you 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
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
3.Close electrical disconnects to energize system.
5