5
Accessory usage guideline
* For tubing line sets between 50 and 175 ft and/or 20 ft elevation difference between indoor and outdoor units, refer to the Application Guideline and Service Man-
ual—Air Conditioners and Heat Pumps Using Puron® Refrigerant.
† Required for all applications.
Accessory description and usage (Listed alphabetically)
1. Coastal Filter
A mesh screen inserted under the top cover and inside the base pan to protect the condenser coil from salt damage without restricting airflow.
SUGGESTED USE: In geographic areas where salt damage could occur.
2. Compressor Start Assist — Capacitor and Relay
Start capacitor and start relay gives hard boost to compressor motor at each start-up.
SUGGESTED USE: Installations where interconnecting tube length exceeds 50 ft.
Installations where outdoor design temperature exceeds 105°F (40.6°C).
Units installed with Low-Ambient Pressure Switch.
3. Compressor Start Assist — PTC Type
Solid state electrical device which gives a soft boost to the reciprocating compressor at each start-up.
SUGGESTED USE: Installations with marginal power supply.
4. Crankcase Heater
An electric resistance heater which mounts to the base of the compressor to keep the lubricant warm during off cycles. Improves compressor lubrication on restart and minimizes chance
of refrigerant slugging. May or may not include a thermostat control.
SUGGESTED USE: When interconnecting tube length exceeds 50 ft.
When unit will be operated below 55°F (12.8°C) outdoor air temperature. (Use with Low-Ambient Pressure Switch.)
All commercial installations.
5. Evaporator Freeze Thermostat
An SPST temperature actuated switch which stops unit operation when evaporator reaches freeze-up conditions.
SUGGESTED USE: All units to which Low-Ambient Pressure Switch has been added.
6. Filter Drier— Suction Line
A device for removing contaminants from refrigerant circulating in a heat pump system; 2-direction flow for heat pumps.
SUGGESTED USE: Split-system heat pumps.
7. Isolation Relay
An SPDT relay which switches the Low-Ambient Controller out of the outdoor fan motor circuit when the heat pump switches to heating mode.
SUGGESTED USE: All heat pumps where Low-Ambient Pressure Switch has been added.
8. Liquid-Line Solenoid Valve (LSV)
An electrically operated shutoff valve to be installed at the outdoor unit and which stops and starts refrigerant liquid flow in response to compressor operation. Maintains a column of
refrigerant liquid ready for action at next compressor operation cycle.
SUGGESTED USE: In long-line applications. (Refer to the Residential Split-System Long-Line Application Guideline and Service Manual.)
9. Low-Ambient Pressure Switch
A long life pressure switch which is mounted to outdoor unit service valve. It is designed to cycle the outdoor fan motor in order to maintain head pressure within normal operating
limits (approximately 200 psig to 365 psig). The control will maintain working head pressure at low-ambient temperatures down to 0°F (–17.8°C) when properly installed.
SUGGESTED USE: Cooling operation at outdoor temperatures below 55°F (12.8°C).
10. Outdoor Air Temperature Sensor
A device that allows the temperature at a remote location (outdoors) to be displayed at the thermostat.
SUGGESTED USE: All Carrier programmable thermostats.
11. Outdoor Thermostat
An SPDT temperature actuated switch which turns on supplemental electric heaters when outdoor air temperature drops below set point.
SUGGESTED USE: Heat pump installations with multiple-stage supplemental heaters.
12. Pressure Guard™ Kit
A pressure-switch kit that cycles the outdoor fan to limit the heating head pressure below a pre-determined pressure setting.
SUGGESTED USE: Some local codes may require limiting the heating head pressure in the vapor line in some applications.
13. Secondary Outdoor Thermostat
An SPDT temperature actuated switch which turns on third stage of supplemental electric heaters when outdoor air temperature drops below the second-stage set point.
SUGGESTED USE: Some local codes may require limiting the heating head pressure in the vapor line in some applications.
14. Snow Stand
Coated wire rack which supports unit 18 in. above mounting pad to allow for drainage from unit base.
SUGGESTED USE: Heat pump installations in heavy snowfall areas.
Heat pump installations in snowdrift locations.
Heat pump installations in areas of prolonged subfreezing temperatures.
All commercial installations.
ACCESSORY
REQUIRED FOR LOW-AMBIENT
APPLICATIONS
(BELOW 55°F)
REQUIRED FOR LONG-LINE
APPLICATIONS*
(OVER 50 FT)
Crankcase Heater
Yes
Yes
Evaporator Freeze Thermostat
Yes
No
Compressor Start Assist — Capacitor and Relay
Yes
Yes
Puron Low Ambient Pressure Switch
Yes
No
Wind Baffle
See Low-Ambient
Pressure Switch Instructions
No
Support Feet
Recommended
No
Puron Hard Shutoff TXV
Yes†
Yes†
Puron Liquid-Line Solenoid Valve for Heating
No
See Long-Line
Application Guideline
