McQuay WHR 017EW

Product Manual WHR-2 7
Part Load Efficiencies
Part load efficiencies and Integrated Part Load Values (IPLV) for EW units are calculated according to
the requirements of the latest ARI Standard 550/590-98 and meet or exceed ASHRAE Efficiency
Standard 90.1. Since most air conditioning systems operate at less than design full load a majority of
the time, IPLV is an excellent method for comparing chillers' efficiencies.
Noise
All McQuay WHR chillers are equipped with hot gas discharge line mufflers in each refrigerant circuit
to reduce the overall sound levels. An optional insulated acoustical compressor enclosure to further
reduce sound levels is also available for most units. Sound level ratings are contained in the Sound
Rating section of this manual.
Unit Base
Designed for easy handling, the units are mounted on a compact, rugged formed steel base. Isolator
mounting holes are provided.
Electrical Control Center
Shipped with all operating and safety controls and motor starting equipment factory wired,
operationally tested, and ready for operation. All controls are centrally located in a hinged control
center with keylocked doors.
Part-winding starters are standard on 208/230 volt applications and available as a special on 460/575
volts. Across-the-line starters are standard on 380/460/575 volts.
A five-minute, solid-state lockout timer is provided to delay compressor restart after safety cutout or
power interruption, or under irregular cooling load demands. A lead lag switch is standard on all units
(WHR 040 – WHR 210) not incorporating the single circuit hot gas bypass option.
Evaporator
The evaporator is a direct expansion, shell-and-tube type with water flowing in the baffled shell side
and refrigerant flowing through the tubes.
The evaporator is constructed with a carbon steel shell and seamless high efficiency copper tubes,
roller expanded into heavy carbon steel tube sheets. Water baffles are polypropylene to resist
corrosion.
Refrigerant heads are carbon steel with multi-pass baffles to ensure oil return and are removable to
permit access to the tubes from either end. For water removal, 3/8" (10mm) vent and drain plugs are
provided on the top and bottom of the shell. Two 1/2” (12.7mm) couplings on each water nozzle allow
for easy field installation of sensor equipment.
The evaporator is wrapped with 3/4” (19.1mm) thick vinyl nitrate polymer sheet insulation. The
insulation has a K factor of 0.28 at 75°F (24°C). The insulation is fitted and cemented in place, then
painted with a resilient vinyl base paint to resist cracking.
The tube side maximum working pressure is 225 psig (1552kPa). The waterside working pressure is 175
psig (1206kPa). All evaporators are designed, constructed, inspected and stamped according to the
requirements of the ASME Boiler and Pressure Vessel Code.