
13
920-075-08
III. Chassis Operation
9) Remote Thermostat Control
Thechassisrequiresasimplesinglestageheat-coolwallthermostat.
Each chassis comes with a terminal strip located in the electrical
controlbox.Allinternalchassiswiring(low&highvoltage)isfactory
ready for 230 Volt operation. For 208 Volt operation a single wire
MUSTBECHANGEDONTHETRANSFORMER. RefertoFigure
7 on page 9.
10) Low Ambient Protection
Each chassis is equipped with Low Ambient Protection in the form of
a suction line thermostat. This thermostat will prevent compressor
operation at low suction line temperatures. Each chassis is also
equipped with a factory installed bellows that will drain water from
the base pan to prevent the fan slinger from freezing during winter
weather.
11) Heating Defrost (Heat Pump Models Only)
All Heat Pumps have a passive heating defrost system. Defrost
occurs as needed and automatically switches to electric heat during
defrost.Whentheoutdoorambienttemperaturedropsbelowa45°F
factory setting, the chassis automatically switches to electric heat.
As outdoor ambient temperatures rise above 45°F, the chassis
returnstotheheatpumpmode.Thechangeovertemperatureisuser
adjustable from approximately 32°F - 55°F. The defrost thermostat
may also be used to lock out the compressor in an emergency
heat situation.
12) Fresh Air Door
The Fresh Air Door is an "intake" system. The fresh air door is
opened via a slide on the front of the chassis located just above
the indoor coil. Move the slide left to open and right to close the
fresh air door. The system is capable of up to 60 CFM of fresh air
@ ~.3" H20 internal static pressure.
13) Condensate Disposal System
Theinternal drain connections are 3/4"FPTfittingsontheright,left
andoutdoorsideoftheunit.SeeFigure10onpage12.Thechassis
is designed with a condensate drain system that has 3 parts. The
three parts work as follows:
Part 1: The system’s first stage increases energy efficiency
utilizing a factory installed fan that slings the cold
condensate onto the hot outdoor coil.
Part 2: When high outdoor humidity prevents the slinger from
disposing of all the condensate, the excess condensate
overflows into the internal drain connection.
Part 3: If Parts 1 & 2 fail for any reason, excess condensate
overflows from a spillway directly into the wall plenum
to the outside of the building. IF THIS OCCURS, THIS
IS YOUR WARNING THAT THE CHASSIS OR DRAIN
NEEDS SERVICING.
Follow all codes when working with the condensate drain
system. A secondary drain pan may be placed beneath the
chassis to prevent condensated spillage due to improper
installation or unit malfunction.
IV. Service & Warranty
14) Servicing / Chassis Quick Changeouts
The chassis is designed for quick disconnect and change out. For
minor electrical service, the control box cover lifts straight up after
the screws & disconnect head are removed. For major electrical,
refrigeration and fan service the chassis must be removed from
utility closet.
To Remove the Chassis from the Closet:
A Switch the wall thermostat off.
B Pull the power disconnect located in the front of the chassis.
C Turn off all power to the unit at the main breaker or
disconnect.
D Disconnect the thermostat wiring.
E Disconnect the electrical connection.
F Disconnect the ductwork.
G Disconnect the drain connection.
H Slide the chassis out of the wall plenum.
I Lift the chassis out of the utility closet.
15) Warranty
All service work must be done by a qualified servicer. See
Warranty on the next page, and consult your dealer or contractor
for details.
Electrical shockand movingparts hazard cancauseinjury
or death. Pull out the disconnect head found on the front
of the chassis before servicing.