American Standard RT-SVX39B-EN User Manual
Maintenance
Monthly Maintenance
Before completing the following chec ks, turn the unit OFF
and lock the main power disconnect switch open.
WARNING
Rotating Components!
Disconnect all electric power, including remote
disconnects before servicing . Follow proper lockout/
tagout procedures to ensure the power can not be
inadvertently energized. Failure to disconnect power
before servicing could result in death or serious injury.
Failure to disconnect power before servicing can cause
severe personal injury or death.
Filters
• Inspect the return air filters. Clean or replace them if
necessary. Refer to the unit Service Facts for filter
information.
Cooling Season
• Check the unit’s drain pans and condensate piping to
ensure that there are no blockages.
• Inspect the evaporator and condenser coils for dirt,
bent fins, etc. If the coils appear dirty, clean them
according to the instructions described in “Coil
Cleaning” later in this section.
• Manually rotate the condenser fan(s) to ensure free
movement and check motor bearings for wear. Verify
that all of the fan mounting hardware is tight.
• Inspect the F/A-R/A damper hinges and pins to ensure
that all moving parts are securely mounted. Keep the
blades clean as necessary.
• Verify that all damper linkages move freely; lubricate
with white grease, if necessary.
• Check supply fan motor bearings; repair or replace the
motor as necessary.
• Check the fan shaft bearings for wear. Replace the
bearings as necessary.
• Check the supply fan belt. If the belt is frayed or worn,
replace it. Refer to the “Fan Belt Adjustment” section
for belt replacement and adjustments.
• 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 condition s (e.g.,
loose access panels, leaking piping connections, etc.).
• Make sure that all retaining screws are reinstalled in
the unit access panels once these chec ks are complete.
• With the unit running, c h eck and record the: ambient
temperature; compressor suction and discharge
pressures (each circuit); superheat (each circuit);
Record this data on an “operator’s maintenance log” like
the one shown in T able 8, p. 36. If the operating pressures
indicate a refrigerant shortage, measure the system
superheat. For guidelines, refer to the “Compressor Star tUp” section.
Important: 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.
Heating Season
• Inspect the unit’s air filters. If necessary, clean or
replace them.
• Check supply fan motor bearin gs; repair or replace the
motor as necessary.
• 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.
• Verify that the electric heat system operates properly.
Coil Cleaning
Regular coil maintenance, including annual cleaning,
enhances the unit’s operating efficiency by minimizing:
compressor head pressure and amperage draw;
evaporator water carryover; fan brake horsepower, due to
increase static pressure losses; airflow reduction.
At least once each year , or more often if the unit is located
in a “dirty” environment, clean the evaporator and
condenser coils using the instructions outlined below. Be
sure to follow these instructions as closely as possible to
avoid damaging the coils.
Note: For units equipped with hail guards follow removal
procedure listed below.
Hail Guard Removal
Figure 29. Slide-style
34 RT-SVX39B-EN
Maintenance
• Unlatch hail guards.
• Pull the top of the hail guard outward until the fastener
studs are free of the retaining nuts.
• Lift the hail guard from the lower retaining brac ket and
set aside.
To clean refrigerant coils, use a soft brush and a sprayer
(either a garden pump-up type or a high-pressure sprayer).
A high-quality detergent is also required; suggested
brands include “SPREX A.C.”, “O AKITE 161”, “O AKITE 166”
and “COILO X”. If the detergent selected is strongly alkaline
(ph value exceeds 8.5), add an inhibitor.
WARNING
Hazardous Chemicals!
Coil cleaning agents can be either acidic or highly
alkaline. Handle chemical carefully. Proper handling
should include goggles or face shield, chemical
resistant gloves, boots, apron or suit as required. For
personal safety refer to the cleaning agent
manufact u rer’s Materials Safety Data Sheet and follow
all recommended safe handling practices. Failure to
follow all safety instructions could result in death or
serious injury.
1 . Remove enough panels from the un it to gain access to
the coil.
2. Protect all electrical devices such as motors and
controllers from any over spray.
3. Straighten any bent coil fins with a fin comb.
4. Mix the detergent with water according to the
manufacturer’s instructions. If desired, heat the
solution to 150°F maximum to improve its cleansing
capability.
6. Spray the leaving-airflow side of the coil first; then
spray the opposite side of the coil. Allow the cleaning
solution to stand on the coil for five minutes.
7. Rinse both sides of the coil with cool, clean water.
8. Inspect both sides of the coil; if it still appears to be
dirty, repeat Step 6 and Step 7.
9. Reinstall all of the compo nents and panels removed in
Step 1 and any protective covers installed in Step 2.
Note: For units equipped with hail guards follow
reinstallation procedure listed below.
Hail Guard Reinstallation
To reinstall the hail guard, locate the bottom of the hail
guard in the lower bracket and secure it to the upper unit
bracket with the attached fastener s.
Note: Secure hail guard latches.
WARNING
Hazardous Pressures!
Coils contain refriger ant under pressur e. When cleaning
coils, maintain coil cleaning solution temperatu re under
150°F to avoid excessive pressure in the coil. Failure to
follow these safety precautions could result in coil
bursting, which could result in death or serious injury.
Do not heat the detergent-and-water solution above 150°F.
Hot liquids sprayed on the exterior of the coil will raise the
coil’ s internal pressure and may cause it to burst. Failure to
follow proper procedures can result in personal illness or
injury or severe equipment damage.
5. Pour the cleaning solution into the sprayer. If a highpressure sprayer is used:
a. do not allow sprayer pressure to exceed 600 psi.
b. the minimum nozzle spray angle is 15 degrees.
c. maintain a minimum clearance of 6" between the
sprayer nozzle and the coil.
d. spray the solution perpendicular (at 90 degrees) to
the coil face.
RT-SVX39B-EN 35
Maintenance
Final Process
For future reference, you may find it helpful to record the
unit data requested in the blanks provided.
Complete Model Number
Unit Serial Number
Table 8. Sample maintenance log
Refrigerant Circuit #1 Refrigerant Circuit #2
Date
Current
Ambient
Temp. F/C
Compr.
Oil Level
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
Suct.
Press.
Psig/
kPa
Disch.
Press.
Psig/
kPa
Liquid
Press.
Psig/
kPa
Super
-heat
F/C
Wiring Diagram Numbers (from unit control panel)
Schematics
Connections
Subcool.
F/C
Compr.
Oil
Level
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
- ok
- low
Suct.
Press.
Psig/kPa
Disch.
Press.
Psig/
kPa
Liquid
Press.
Psig/
kPa
Superheat
F/C
Subcool.
F/C
36 RT-SVX39B-EN
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