Specs

6
Accessory Description and Usage (Listed Alphabetically)
1. Ball-- Bearing Fan Motor
A fan motor with ball bearings which permits speed reduction
while maintaining bearing lubrication.
Usage Guideline:
Required on all units when using MotorMasterr
2. Compr essor Start Assist -- Capacitor and Relay
Start capacitor and relay gives a hard boost to compressor motor at
each start up.
Usage Guideline:
Required for reciprocating compressors in the following
applications:
Long line
Low ambient cooling
Hard shut off expansion valve on indoor coil
Liquid line solenoid on indoor coil
Required for single--phase scroll compressors in the
following applications:
Long line
Low ambient cooling
Suggested for all compressors in areas with a history of
low voltage problems.
3. Compressor Start Assist — PTC Type
Solid state electrical device which gives a soft boost to the
compressor at each start--up.
Usage Guideline:
Suggested for single phase unit 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 the chance of
liquid slugging.
Usage Guideline:
Required in low ambient cooling applications.
Required in long line applications.
Suggested in all commercial applications.
5. Evaporator Freeze Thermostat
An SPST temperature-- actuated switch that stops unit operation
when evaporator reaches freeze--up conditions.
Usage Guideline:
Required when low ambient kit has been added.
6. 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.
Usage Guideline:
Required in all heat pumps where low ambient kit has
been added.
7. Liquid --Line Solenoid Valve (LLS)
An electrically operated shutoff valve which stops and starts
refrigerant liquid flow in response to compressor operation. It is to
be installed at the outdoor unit to control refrigerant off cycle
migration in the heating mode.
Usage Guideline:
An LLS is required in all long line heat pump
applications to control refrigerant off cycle migration in
the heating mode. See Long Line Guideline.
8. Low --Ambient Pressure Switch Kit
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. The
control will maintain working head pressure at low--ambient
temperatures down to 0_F(--18_C) when properly installed.
Usage Guideline:
A Low --Ambient Pressure Switch or MotorMasterr
Low--Ambient Controller must be used when cooling
operation is used at outdoor temperatures below 55_F
(12.8_C).
9. MotorMasterr Low--Ambient Controller
A fan--speed control device activated by a temperature sensor,
designed to control condenser fan motor speed in response to the
saturated, condensing temperature during operation in cooling
mode only. For outdoor temperatures down to -- 20_F (--28.9_C), it
maintains condensing temperature at 100_F 10_F (37.8_C 
6.5_C).
Usage Guideline:
A MotorMasterr Low Ambient Controller or
Low--Ambient Pressure Switch must be used when
cooling operation is used at outdoor temperatures
below 55_F (12.8_C).
Suggested for all commercial applications.
10. Outdoor Air Temperature Sensor
Designed for use with Payne Thermostats listed in this publication.
This device enables the thermostat to display the outdoor
temperature. This device also is required to enable special
thermostat features such as auxiliary heat lock out.
Usage Guideline:
Suggested for all Payne thermostats listed in this
publication.
11. Outdoor Thermostat
An SPDT temperature--actuated switch which turns on
supplemental electric heaters when outdoor air temperature drops
below a user--selected set point.
Usage Guideline:
Electric supplemental heat applications in non--variable
speed indoor units when electric heat staging is desired.
12. 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.
Usage Guideline:
Outdoor thermostat applications where electric heater is
capable of 3--stage operation.
13. Snow Stand Rack
Coated wire rack which supports unit 18 in. (457.2 mm) above
mounting pad to allow for drainage from unit base.
Usage Guideline:
Suggested in the following applications:
Heat pump installations in heavy snowfall areas.
Heat pump installations in snow drift locations.
Heat pump installations in areas of prolonged
subfreezing temperatures.
All commercial installations.
with MRCOOL Thermostats listed in this publication.
MRCOOL thermostats listed in this