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RT-SVX24Q-EN
shaft is held securely to the bearings and fan
wheels. Make sure that all bearing braces are tight.
☐ Check the supply fan belt(s). If the belts are frayed
or worn, replace them. Refer to the “Fan Belt
Adjustment,” p. 195 for belt replacement and
adjustments.
☐ 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
following:
– 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 81, p. 209. If the operating
pressures indicate a refrigerant shortage, measure the
system superheat and system subcooling. For
guidelines, refer to “Charging by Subcooling ,” p. 178.
IImmppoorrttaanntt:: 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
WWAARRNNIINNGG
HHaazzaarrddoouuss VVoollttaaggee!!
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rreessuulltt iinn ddeeaatthh oorr sseerriioouuss iinnjjuurryy..
DDiissccoonnnneecctt aallll eelleeccttrriicc ppoowweerr,, iinncclluuddiinngg rreemmoottee
ddiissccoonnnneeccttss bbeeffoorree sseerrvviicciinngg.. FFoollllooww pprrooppeerr
lloocckkoouutt//ttaaggoouutt pprroocceedduurreess ttoo eennssuurree tthhee ppoowweerr
ccaann nnoott bbee iinnaaddvveerrtteennttllyy eenneerrggiizzeedd.. VVeerriiffyy tthhaatt nnoo
ppoowweerr iiss pprreesseenntt wwiitthh aa vvoollttmmeetteerr..
Before completing the following checks, turn the unit
OOFFFF and lock the main power disconnect switch open.
☐ Inspect the unit air filters. If necessary, clean or
replace them.
☐ Check supply fan motor bearings; repair or replace
the motor as necessary.
☐ Check the fan shaft bearings for wear. Replace the
bearings as necessary.
NNoottee:: These bearing are considered permanently
lubricated for normal operation. For severe
dirty applications, if relubrication becomes
necessary, use a lithium based grease. See
Table 72, p. 194 for recommended greases.
IImmppoorrttaanntt:: The bearings are manufactured using a
special synthetic lithium-based grease
designed for long life and minimum
relube intervals. Over lubrication can be
just as harmful as not enough.
☐ Use a hand grease gun to lubricate these 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 units only - Check the heat exchanger(s) for any
corrosion, cracks, or holes.
☐ Check the combustion air blower for dirt or
blockage from animals or insects. Clean as
necessary.
NNoottee:: Typically, it is not necessary to clean the gas
furnace. However, if cleaning does become
necessary, remove the burner inspection
plate from the back 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 startup procedure described in “(Constant
Volume and Variable Air Volume Systems),” p. 179.
SSeerrvviiccee aanndd MMaaiinntteennaannccee
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