Trane INTELLIPAK ™ ™ ™ ™ ™ Commercial Single-Zone Rooftop Air Conditioners with CV or VAV Control - Manual (Page 110)

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Service & Maintenance (Continued)
[ ] Check the condition of the gasket around the control
panel doors. These gaskets must fit correctly and be in
good condition to prevent water leakage.
[ ] Verify that all wire terminal connections are tight.
[ ] Remove any corrosion present on the exterior surfaces
of the unit and repaint these areas.
[ ] Generally inspect the unit for unusual conditions (e.g.,
loose access panels, leaking piping connections, etc.)
[ ] Make sure that all retaining screws are reinstalled in the
unit access panels once these checks are complete.
[ ] With the unit running, check and record the:
ambient temperature;
compressor oil level (each circuit);
compressor suction and discharge pressures (each
circuit);
superheat and subcooling (each circuit);
Record this data on an “operator’s maintenance log” like
the one shown in Table 5-8. If the operating pressures in-
dicate a refrigerant shortage, measure the system super-
heat and system subcooling. For guidelines, refer to
"Charging by Subcooling".
Note: Do Not release refrigerant to the
atmosphere! If adding or removing refrigerant is
required, the service technician must comply with
all federal, state and local laws. Refer to general
service bulletin MSCU-SB-1 (latest edition).
Heating Season
Before completing the following checks, turn the unit OFF
and lock the main power disconnect switch open.
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote discon-
nects before servicing. Follow proper lockout/tagout
procedures to ensure the power can not be inadvert-
ently energized. Failure to disconnect power before ser-
vicing could result in death or serious injury.
[ ] Inspect the unit’s air filters. If necessary, clean or replace
them.
[ ] Check supply fan motor bearings; repair or replace the
motor as necessary.
[ ] Lubricate the supply fan bearings with a lithium based
grease. Refer to Table 5-6 for recommended greases.
Note: The bearings are manufactured using a
special synthetic lithium based grease designed for
long life and minimum lube intervals. Too much
lubrication in a bearing can be just as harmful as
not enough.
Use a hand grease gun to lubricate the bearings; add
grease until a light bead appears all around the seal. Do not
over lubricate!
After greasing the bearings, check the setscrews to ensure
that the shaft is held securely. Make sure that all bearing
braces are tight.
[ ] Inspect both the main unit control panel and heat section
control box for loose electrical components and terminal
connections, as well as damaged wire insulation. Make
any necessary repairs.
[ ] Gas Heat Units only - Check the heat exchanger for any
corrosion, cracks, or holes.
[ ] Check the combustion air blower for dirt. Clean as neces-
sary.
Note: Typically, it is not necessary to clean the gas
furnace. However, if cleaning does become
necessary, remove the burner inspection plate from
the rear of the heat exchanger to access the drum.
Be sure to replace the existing gaskets with new
ones before reinstalling the inspection plate.
[ ] Open the main gas valve and apply power to the unit
heating section; then initiate a "Heat" test using the start-
up procedure described in "Gas Furnace Start-Up".
WARNING
Hazardous Gases and Flammable Vapors!
Exposure to hazardous gases from fuel substances
have been shown to cause cancer, birth defects or
other reproductive harm. Improper installation, adjust-
ment, alteration, service or use of this product could
cause flammable mixtures. To avoid hazardous gases
and flammable vapors follow proper installation and set
up of this product and all warnings as provided in this
manual. Failure to follow all instructions could result in
death or serious injury.
When using dry nitrogen cylinders for pressurizing
units for leak testing, always provide a pressure regula-
tor on the cylinder to prevent excessively high unit
pressures. Never pressurize unit above the maximum
recommended unit test pressure as specified in appli-
cable unit literature. Failure to properly regulate pres-
sure could result in a violent explosion, which could re-
sult in death or serious injury or equipment or prop-
erty-only-damage.
[ ] Verify that the ignition system operates properly.
Coil Cleaning
Regular coil maintenance, including annual cleaning—en-
hances the unit’s operating efficiency by minimizing:
compressor head pressure and amperage draw;
water carryover;
fan brake horsepower; and,
static pressure losses.
At least once each year—or more often if the unit is located
in a “dirty” environment—clean the evaporator and con-
denser coils using the instructions outlined below. Be sure
to follow these instructions as closely as possible to avoid
damaging the coils.