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3
Fig. 2 — Typical Access Panel Location (Back)
Routine Maintenance
These items should be part of a routine maintenance program, to
be checked every month or two, until a specific schedule for each
can be identified for this installation:
QUARTERLY INSPECTION (AND 30 DAYS AFTER INI
-
TIAL START)
• Return air filter replacement
• Outdoor hood inlet filters cleaned
• Belt tension checked
• Belt condition checked
• Pulley alignment checked
• Fan shaft bearing locking collar tightness checked
• Condenser coil cleanliness checked
• Condensate drain checked
Seasonal Maintenance
These items should be checked at the beginning of each season (or
more often if local conditions and usage patterns dictate):
AIR CONDITIONING
• Condenser fan motor mounting bolts tightness
• Compressor mounting bolts
• Condenser fan blade positioning
• Control box cleanliness and wiring condition
• Wire terminal tightness
• Refrigerant charge level
• Evaporator coil cleaning
• Evaporator blower motor amperage
HEATING
• Heat exchanger flue passageways cleanliness
• Gas burner condition
• Gas manifold pressure
• Heating temperature rise
ECONOMIZER OR OUTSIDE AIR DAMPER
• Inlet filters condition
• Check damper travel (economizer)
• Check gear and dampers for debris and dirt
AIR FILTERS AND SCREENS
Each unit is equipped with return air filters. If the unit has an econ
-
omizer, it will also have an outside air screen. If a manual outside
air damper is added, an inlet air screen will also be present. Each
of these filters and screens will need to be periodically replaced or
cleaned.
RETURN AIR FILTERS
Return air filters are disposable fiberglass media type. Access to
the filters is through the vertical panel to the right of the control
box. Filters are situated on slide out racks for easy inspection and
repair. (See Fig. 1.)
To remove the filters:
1. Remove vertical filter access door.
2. Reach inside and extract the filters from the filter rack.
3. Replace these filters as required with similar replacement fil
-
ters of same size.
4. Re-install filter access panel.
OUTSIDE AIR HOOD
Outside air hood inlet screens are permanent aluminum-mesh type
filters. Check these for cleanliness. Remove the screens when
cleaning is required. Clean by washing with hot low-pressure wa
-
ter and soft detergent and replace all screens before restarting the
unit. Observe the flow direction arrows on the side of each filter
frame.
Economizer Inlet Air Screen
This air screen is retained by spring clips under the top edge of the
hood. (See Fig. 3.)
To remove the filter, remove screws in horizontal filter retainers
on leading edge of hood. Move filters into pocket at the end of
hood and slide filters out.
To re-install filters, insert clean or new filters into pocket created at
the end of the hood, then slide filters into place. Once positioned,
re-install horizontal filter retainer.
Fig. 3 — Filter Installation
SUPPLY FAN (BLOWER) SECTION
Supply Fan (Belt-Drive)
The supply fan system consists of a forward-curved centrifugal
blower wheel on a solid shaft with two concentric type bearings,
one on each side of the blower housing. A fixed-pitch driven pul
-
ley is attached to the fan shaft and an adjustable-pitch driver pulley
CONDENSER COIL
CIRCUIT A
CONDENSER COIL
CIRCUIT B
COMPRESSOR
CIRCUIT B
IMPORTANT: DO NOT OPERATE THE UNIT WITHOUT
THESE FILTERS!
CAUTION
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could cause personal injury or
death.
Before performing service or maintenance operations on the
fan system, shut off all unit power and lockout/tag-out the unit
disconnect switch. DO NOT reach into the fan section with
power still applied to unit.