Carrier Comfort 25HCR3C, Product Data

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5
ACCESSORY USAGE GUIDELINE
Accessory
REQUIRED FOR
LOW---AMBIENT APPLICATIONS
(Below 55
°
F / 12.78
°
C)
REQUIRED FOR LONG
LINE APPLICATIONS*
(Over 80 Ft. / 24.38 m)
REQUIRED FOR SEA
COAST APPLICATIONS
(Within 2 miles / 3.22 km)
Ball Bearing Fan Motor Yes
{
No No
Compressor Start Assist
Capacitor and Relay
Yes
{
Yes No
Crankcase Heater Yes
{
Yes No
Evaporator Freeze Thermostat Yes
{
No No
Isolation Relay Yes
{
No No
Liquid Line Solenoid Valve No
See Long Line Application
Guideline
No
Motor Master
®
Control
or Low---ambient Pressure Switch
Yes
{
No No
Support Feet
Recommended No Recommended
* For tubing line sets between 80 and 200 ft. (24.38 and 60.96 m) and/or 20 ft. vertical (6.09 m) differential, refer to Residential Split System Long Line
Application Guideline.
{
Required for Low---Ambient Controller MotorMaster
r
Control only.
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 MotorMaster
r
is used.
2. Compressor 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 in 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. Cycle Protector
The cycle protector is designed to prevent compressor short
cycling. This control provides an approximate 5--minute delay after
power to the compressor has been interrupted for any reason,
including power outage, protector control trip, thermostat jiggling,
or normal cycling.
6. 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.
7. High Pressure Switch
A high pressure switch that protects unit against excessive pressure.
Usage Guideline:
Required in all heat pumps operated in dual fuel
applications.
8. 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.
9. 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.
10. 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
(approximately 100 psig to 225 psig). The control will maintain
working head pressure at low--ambient temperatures down to
0
_
F/--17.78
_
C when properly installed.
Usage Guideline:
A Low--Ambient Pressure Switch or MotorMaster
r
Low--Ambient Controller must be used when cooling
operation is used at outdoor temperatures below 55
_
F
(12.8
_
C).
25H
C
R
3C