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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 low-ambient controller (full modulation feature) or MotorMaster®—Low-Ambient Controller is installed.
2.
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.
3.
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
Hard shut off expansion valve on indoor coil
Liquid line solenoid on indoor coil
Required for scroll compressors in the following applications:
Long line
Low ambient
Suggested for all compressors in areas with a history of low voltage problems.
4.
Compressor Start Assist — PTC Type
Solid state electrical device which gives a "soft" boost to the reciprocating compressor at each start-up.
Usage Guideline:
Suggested in installations with marginal power supply.
5.
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 applications.
Required in long line applications.
Suggested in all commercial applications.
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.
Liquid-Line Solenoid Valve (LLS)
This device serves two purposes. It is an electrically operated shutoff valve which stops and starts refrigerant liquid flow in response to compressor operation.
It maintains a column of refrigerant liquid ready for action at next compressor operation cycle. It also provides system protection against off-cycle refrigerant
migration.
Note:
When LLS is used with reciprocating compressors, Compressor Start Assist — Capacitor and Relay is required.
Usage Guideline:
Required in air conditioner long line applications with a piston indoor metering device to prevent off cycle refrigerant migration. A hard shut
off TXV can be used instead of an LLS in single flow air conditioner applications. See Long Line Application Guideline.
8.
MotorMaster®—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 temper-
ature 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
± –12°C).
Usage Guideline:
A MotorMaster®—Low Ambient Controller or Low-Ambient Pressure Switch must be used when cooling operation is used at outdoor tem-
peratures below 55°F (12.8°C).
Suggested for all commercial applications.
9.
Outdoor Air Temperature Sensor
Designed for use with Carrier 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 Carrier thermostats listed in this publication.
10.
Sound Hood
Wraparound sound reducing cover for the compressor. Reduces the sound level by about 2 dBA.
Usage Guideline:
Suggested when unit is installed closer than 15 ft to quiet areas—bedrooms, etc.
Suggested when unit is installed between two houses less than 10 ft apart.
11.
Support Feet
Four stick-on plastic feet that raise the unit 4 in. above the mounting pad. This allows sand, dirt, and other debris to be flushed from the unit base, minimizing
corrosion.
Usage Guideline:
Suggested in the following applications:
Coastal installations.
Windy areas or where debris is normally circulating.
Rooftop installations.
For improved sound ratings.
12.
Thermostatic Expansion Valve (TXV)
A modulating flow-control valve which meters refrigerant liquid flow rate into the evaporator in response to the superheat of the refrigerant gas leaving the
evaporator. Kit includes valve, adapter tubes, and external equalizer tube. Hard shut off types are available.
Note:
When using a hard shut off TXV with single phase reciprocating compressors, a Compressor Start Assist — Capacitor and Relay is required.
Usage Guideline:
Required to achieve ARI ratings in certain equipment combinations. Refer to combination ratings.
Hard shut off TXV or LLS required in air conditioner long line applications.
Required for use on all zoning systems.
13.
Time-Delay Relay
An SPST delay relay which briefly continues operation of indoor blower motor to provide additional cooling after the compressor cycles off.
Note:
Most indoor unit controls include this feature. For those that do not, use the guideline below.
Usage Guideline:
For improved efficiency ratings for certain combinations of indoor and outdoor units. Refer to ARI Unitary Directory.