6
ACCESSORY USAGE GUIDELINE
ACCESSORY
REQUIRED FOR
LOW---AMBIENT COOLING APPLICA-
TIONS
(Below 55
°
F/12.8
_
C)
REQUIRED FOR LONG LINE AP-
PLICATIONS*
(Over 80 ft/24.38 m)
REQUIRED FOR SEA COAST
APPLICATIONS (Within 2
miles/3.22 km)
Crankcase Heater
Standard
Standard
Standard
Evaporator Freeze Protection
Standard with Infinity
t
Control
No
No
Liquid---Line Solenoid Valve
No
Yes
No
Low---Ambient Control
Standard with Infinity Control
No
No
Puron Refrigerant Balance Port Hard---
ShutOff TXV
Yes
{
Yes
{
Yes
{
Support Feet
Recommended
No
Recommended
Winter Start Control
Standard with Infinity Control
No
No
* For tubing set lengths between 80 and 200 ft. (24.38 and 60.96 m) horizontal or 20 ft. (6.10 m) vertical differential (total equivalent length), refer to the Long
Line Guideline—Air Conditioners and Heat Pumps using Puron
®
Refrigerant
.
{
Required on all indoor units. Standard on all new Greenspeed™ compatible fan coils and furnace coils.
Accessory Description and Usage (Listed Alphabetically)
1. Compressor Start Assist
The inverter drive gently starts the variable speed compressor at all
times. No other start device is compatible with this unit.
2. Crankcase Heater
Compressor motor winding resistance heater which is internal to
compressor to keep the lubricant warm during off cycles. Improves
compressor lubrication on restart and minimizes the chance of
liquid slugging.
Usage:
Used in low ambient cooling applications.
Used in long line applications.
3. 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.
Suggested for all commercial applications.
4. Snow Stand
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.
5. Thermostatic Expansion Valve (TXV) Bi--Flow
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.
Usage Guideline:
Accessory required to meet AHRI rating and system
reliability, where indoor not equipped.
Required in all heat pump applications designed with
Puron refrigerant.
6. Electro--Magnetic Interference Kit
Usage Guideline:
May be required to address radio frequency interference
for equipment, such as HAM radios, operating between 6
and 30 mHz.
25V
N
A
Summary of Contents for 25VNA
Page 8: ...8 DIMENSIONS ENGLISH 25VNA ...
Page 9: ...9 DIMENSIONS SI 25VNA ...
