Unit Arrangement And Access; General; Routine Maintenance; Filters - Carrier 50FC M20 Series Service And Maintenance Instructions

UNIT ARRANGEMENT AND ACCESS

General

Figures 1 and 2 show general unit arrangement and access
locations.
Control Box
Access Panel
Indoor Blower
Access Panel
Electric Heat
Access Panel
Fig. 1 — Typical Access Panel Locations (Front)
Condenser Coil
Circuit A
Condenser Coil
Circuit B
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 INITIAL START)
• Return air filter replacement
• Outdoor hood inlet filters cleaned
• Condenser coil cleanliness checked
• Condensate drain checked
Filter and Indoor Coil Access Panel
Unit Center Post
Compressor
Access Panel
Indoor Blower
Access Panel
Compressor
Circuit B
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
• Ensure outdoor fan motor mounting bolts are tight
• Ensure compressor mounting bolts are tight
• Inspect outdoor fan blade positioning
• Ensure control box is clean
• Check control box wiring condition
• Ensure wire terminals are tight
• Check refrigerant charge level
• Ensure indoor coils are clean
• Check supply blower motor amperage
Electric Heating
• Inspect power wire connections
• Ensure fuses are operational
• Ensure manual reset limit switch is closed
Economizer or Outside Air Damper
• Check 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 re-
placed or cleaned.

Filters

RETURN AIR FILTERS
EQUIPMENT DAMAGE HAZARD
Failure to follow this CAUTION can result in premature wear
and damage to equipment.
DO NOT OPERATE THE UNIT WITHOUT THE RETURN
AIR FILTERS IN PLACE.
Dirt and debris can collect on heat exchangers and coils
possibly resulting in a small fire. Dirt buildup on components
can cause excessive current used resulting in motor failure.
Return air filters are disposable fiberglass media type. Access to
the filters is through the small lift-out panel located on the rear
side of the unit, above the evaporator/return air access panel.
(See Fig. 3.)
To remove the filters:
1. Grasp the bottom flange of the upper panel.
2. Lift up and swing the bottom out until the panel disen-
gages and pulls out.
3. Reach inside and extract the filters from the filter rack.
4. Replace these filters as required with similar replacement
filters of same size.
To re-install the access panel:
1. Slide the top of the panel up under the unit top panel.
2. Slide the bottom into the side channels.
3. Push the bottom flange down until it contacts the top of
the lower panel (or economizer top).
3
CAUTION