York 251934-YTG-J-0910 User Manual
Page 11
251934-YTG-J-0910
Johnson Controls Unitary Products
11
Electric Heating (ZJ/ZR/ZF***C/E Models)
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 capacities. The heating
section shall have a primary limit control(s) and automatic reset
to prevent the heating element system from operating at an
excessive temperature. Units with Electric Heating shall be
wired for a single point power supply with branch circuit fusing
(where required).
Unit Operating Characteristics
Unit shall be capable of starting and running at 125° F outdoor
temperature, exceeding maximum load criteria of ARI Standard
340/360. The compressor, with standard controls, shall be
capable of operation down to 25° F outdoor temperature.
Accessory low ambient kit shall be available for operation to 0°
F. Unit shall be provided with fan time delay to prevent cold air
delivery before heat exchanger warms up (Gas heat only).
Electrical Requirements
All unit power wiring shall enter unit cabinet at a single factory
provided location and be capable of side or bottom entry, to
minimize roof penetrations and avoid unit field modifications.
Separate side and bottom openings shall be provided for the
control wiring.
Standard Limited Warranties
• Compressor 5 Years
• Heat Exchanger 10 Years
• Electric Heat Element 5 Years
• Other Parts 1 Year
Optional Outdoor Air (Shall be made available by either/or):
• Electronic Enthalpy Automatic Economizer - Outdoor
and return air dampers that are interlocked and positioned
by a fully-modulating, spring-return damper actuator. The
maximum leakage rate for the outdoor air intake dampers
shall not exceed 2% when dampers are fully closed and
operating against a pressure differential of 0.5 IWG. A
unit-mounted potentiometer shall be provided to adjust
the outdoor and return air damper assembly to take in
CFM of outdoor air to meet the minimum ventilation
requirement of the conditioned space during normal
operation. During economizer operation, a mixed-air
temperature control shall modulate the outdoor and return
air damper assembly to prevent the supply air
temperature from dropping below 55°F. Changeover from
compressor to economizer operation shall be provided by
an integral electronic enthalpy control that feeds input into
the basic module. The outdoor intake opening shall be
covered with a rain hood that matches the exterior of the
unit. Water eliminator/filters shall be provided.
Simultaneous economizer/compressor operation is also
possible. Dampers shall fully close on power loss.
• Motorized Outdoor Air Dampers - Outdoor and return
air dampers that are interlocked and positioned by a 2-
position, spring-return damper actuator. The maximum
leakage rate for the outdoor air intake dampers shall not
exceed 2% when dampers are fully closed and operating
against a pressure differential of 0.5 IWG. A unit-mounted
potentiometer shall be provided to adjust the outdoor and
return air damper assembly to take in the design CFM of
outdoor air to meet the ventilation requirements of the
conditioned space during normal operation. Whenever the
indoor fan motor is energized, the dampers open up to
one of two pre-selected positions - regardless of the
outdoor air enthalpy. Dampers return to the fully closed
position when the indoor fan motor is de-energized.
Dampers shall fully close on power loss.
Other Pre-engineered Accessories Available
• Roof Curb - 14" high, full perimeter curb with wood nailer
(shipped knocked-down).
• 100% Barometric Relief Damper - Contains a rain hood,
air inlet screen, exhaust damper and mounting hardware.
Used to relieve internal air pressure through the unit.
• Propane Conversion Kit - Contains new orifices and gas
valve parts to convert from natural to L.P. gas. One per
unit required.
• High Altitude - Natural Gas - Contains orifices required
for applications between 2000 and 6000 feet altitude.
• High Altitude - Propane Gas - Contains orifices required
for applications between 2000 and 6000 feet altitude.
Must be used with propane conversion kit.
• Burglar Bars - Designed to work with above roof curbs,
depending on unit model. Fits duct openings of curb
supply and return air openings.
• Side Duct Flange - Supply and return air duct flanges for
side duct applications. Do not use on units with power
exhaust.
• High Static Drive - May include a belt, blower pulley,
motor pulley or a motor change to enhance blower
performance.
• Wood Skid - Allows unit to be handled with 90" forks.
• Economizer/motorized Damper Rain Hood
(ZJ/ZR/ZFN/E/C300 only) - Contains all hood panels and
the hardware for assembling.
• Anti-Recycle Timer - Assures 5-minute off time between
compressor cycles.
• Low Ambient Kit - Provides unit cooling operation down
to 0 °F.
• Coil Guard Kit - Guard for cooling coil.
OTHER FACTORY INSTALLED OPTIONS
• Power Exhaust Option - To work in conjunction with
economizers.
• Stainless Steel Heat Exchanger
• Stainless Steel Drain Pan
• Technicoat Phenolic Coated Condenser And
Evaporator Coil
• Electronic Single Enthalpy Economizer