York D2CE, Technical Manual

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036-21359-001-B-0302
16 Unitary Products Group
B. Evaporator and Condenser coils shall be of the
direct expansion, draw-thru, design.
C. Condenser coils shall be protected with factory
installed coil guards
3. Refrigerant Circuit and Refrigerant Safety Compo-
nents shall include:
A. Balance-port thermostatic expansion valve with
independent circuit feed system.
B. Filter drier/strainer to eliminate any moisture or for-
eign matter.
C. Accessible service gage connections on both suc-
tion and discharge lines to charge, evacuate, and
measure refrigerant pressure during any necessary
servicing or troubleshooting, without losing charge.
D. The refrigeration system shall provide at least 15 °F
of sub-cooling at design conditions.
E. All Models shall have two independent circuits..
4. Unit Controls:
A. Unit shall be complete with self contained low-volt-
age control circuit protected by a resetable circuit
breaker on the 24 volt transformer side.
B. Unit shall incorporate a lock-out circuit which pro-
vides reset capability at the space thermostat or
base unit, should any of the following standard
safety devices trip and shut off compressor:
1. Loss-of-charge/Low-pressure switch.
2. High-pressure switch.
3. Freeze-protection thermostat, evaporator coil.
If any of the above safety devices trip, an LED (light-
emitting diode) indicator shall illuminate.
C. Unit shall incorporate “AUTO RESET” compressor
over temperature, over current protection.
D. Unit shall operate with conventional thermostat
designs and have a low voltage terminal strip for
easy hook-up.
GAS HEATING SECTION (DCG MODELS)
1. Shall be designed with induced draft combustion
with post purge logic and energy saving direct
spark ignition, redundant main gas valve. Ventor
wheel shall be constructed of stainless steel for
corrosion resistance.
2. The heat exchanger shall be of the tubular type,
constructed of T1-40 aluminized steel for corrosion
resistance and allowing minimum mixed air enter-
ing temperature of 25 °F.
3. Burners shall be of the in-shot type, constructed of
aluminum coated steel and contain air mixture
adjustments.
4. All gas piping shall enter the unit cabinet at a single
location through either the side or curb, without any
field modifications.
5. An integrated control board shall provide timed
control of evaporator fan functioning and burner
ignition.
6. Heating section shall be provided with the following
minimum protection:
A. Primary and auxiliary high-temperature limit
switches.
B. Induced draft motor speed sensor.
C. Flame roll out switch (manual reset).
D. Flame proving controls.
7 Unit shall have two independent stages of capacity.
ELECTRIC HEATING (DCE MODELS)
1. Nickel chromium electric heating elements shall be
provided as required by the application with 1 or 2
stage control, as required, from 13.5 KW to 72 KW
capacity.
2. The heating section shall have a primary limit con-
trol(s) and automatic reset to prevent the heating
element system from operating at an excessive
temperature.
3. Units with Electric Heating shall be wired for a sin-
gle point power supply with branch circuit fusing
(where required).
UNIT OPERATING CHARACTERISTICS
1. Unit shall be capable of starting and running at 125
°F outdoor temperature, exceeding maximum load
criteria of ARI Standard 210/240.
2. The compressor, with standard controls, shall be
capable of operation down to 25 °F outdoor tem-
perature. Accessory low ambient kit shall be avail-
able for operation to 0 °F.
3. Unit shall be provided with fan time delay to pre-
vent cold air delivery before heat exchanger warms
up. (Gas heat only)