Carrier Weathermaster 48HJD Series Product Data page 73

F. Heating Section:
1. Induced draft combustion type with energy sav-
ing direct spark ignition system, redundant
main gas valve, and 2-stage heat.
2. The heat exchanger shall be of the tubular sec-
tion type constructed of a minimum of 20 gage
steel coated with a nominal 1.2 mil aluminum-
silicone alloy for corrosion resistance, and shall
have a 10-year warranty.
3. Burners shall be of the in-shot type constructed
of aluminum coated steel.
4. The Integrated Gas Control (IGC) board shall
provide timed control of evaporator fan func-
tioning and burner ignition. An LED (light-
emitting diode) shall provide diagnostic infor-
mation. The LED shall be visible without
removing the control box access panel.
5. IGC board contains anti-cycle protection for gas
heat operation (after 4 continuous cycles on
high temperature limit switch and one cycle on
the flame rollout switch).
G. Refrigerant Components:
Refrigerant circuit components shall include:
1. Acutrol™ feed system.
2. Refrigerant strainer, or filter drier.
3. Service gage connections on suction, discharge,
and liquid lines.
4. Ability to route gage hoses through unit top
cover, or outdoor panel.
H. Filter Section:
1. Standard filter section shall consist of factory-
installed low-velocity, throwaway 2-in. thick
fiberglass filters of commercially available sizes.
2. Filter face velocity shall not exceed 300 fpm at
nominal airflows.
3. Filter section shall use only one size filter.
4. Filters shall be accessible through an access
panel with "tool-less" removal.
I. Controls and Safeties:
1. Unit Controls:
Unit shall be complete with self-contained low-
voltage control circuit protected by a fuse on
the 24-v transformer side.
2. Safeties:
a. Unit shall incorporate a solid-state compres-
sor protector which provides anti-cycle reset
capability at the space thermostat, should
any of the following standard safety devices
trip and shut off compressor.
1) Compressor overtemperature, overcurrent.
2) Loss-of-charge/low-pressure switch.
3) Freeze-protection thermostat, evapora-
tor coil.
4) High-pressure switch.
The lockout protection shall be easily discon-
nected at the control board, if necessary.
b. Heating section shall be provided with the
following minimum protections:
1) High-temperature limit switches.
2) Induced draft motor speed sensor.
3) Flame rollout switch.
4) Flame proving controls.
J. Operating Characteristics:
1. Unit shall be capable of starting and running at
125 F ambient outdoor temperature, meeting
maximum load criteria of ARI Standard 210/
240 or 360 at ±10% voltage.
2. Compressor with standard controls shall be
capable of operation down to 25 F ambient
outdoor temperature.
K. Electrical Requirements:
All unit power wiring shall enter unit cabinet at a sin-
gle factory-predrilled location.
L. Motors:
1. Compressor motors shall be cooled by refriger-
ant passing through motor windings and shall
have line break thermal and current overload
protection.
2. Indoor blower (evaporator-fan) motor shall have
permanently lubricated bearings and inherent
automatic-reset thermal overload protection.
3. Totally enclosed condenser-fan motor shall have
permanently lubricated bearings and inherent
automatic-reset thermal overload protection.
4. Induced draft motor shall have permanently
lubricated, sealed bearings and inherent auto-
matic reset thermal overload protection.
M. Special Features:
Certain features are not applicable when the fea-
tures designated by * are specified. For assistance in
amending the specifications, contact your local
Carrier Sales Office.
* 1. Direct Digital Controls:
a. Shall be available as a factory-installed
option.
b. Shall actively monitor all modes of opera-
tion, as well as evaporator-fan status, filter
status, indoor-air quality, supply-air tempera-
ture, and outdoor-air temperature.
c. Shall work with Carrier TEMP and VVT
systems.
d. Shall have built-in diagnostics for thermostat
commands for both staged heating and cool-
ing, evaporator-fan operation, and econo-
mizer operation.
e. Shall be equipped with a 5-minute time
delay between modes of operation.
2. Roof Curbs:
a. Formed galvanized steel with wood nailer
strip and capable of supporting entire unit
weight.
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