Carrier 50GJ006, Инструкция по установке, запуску и обслуживанию, Страница: 27 / 36

When the second stage of cooling is satisfied, the com-
pressor and outdoor (condenser) fan motor will be de-
energized. The damper position will be determined by the
supply-air temperature.
When the first stage of cooling is satisfied, the damper
will move to fully closed position.
COOLING, 50GJ006 UNITS WITH PARABLADE ECONO-
MIZER — When the outdoor-air is above the enthalpy con-
trol setting, and the room thermostat calls for cooling, the
compressor contactor is energized to start the compressor and
the outdoor (condenser) fan motor. The indoor (evaporator)
fan motor is energized and the economizer damper moves to
the minimum position. After the room thermostat is satisfied
the damper will spring return to the fully closed position.
When the outdoor-air is below the enthalpy control set-
ting and the thermostat calls for cooling, the economizer out-
door air damper is opened proportionally to maintain between
50 and 56 F at the mixed air sensor. If outside air alone can-
not satisfy the cooling requirements, economizer cooling is
integrated with mechanical cooling. When the room thermo-
stat is satisfied, the damper will spring return to the fully
closed position.
COOLING, 50GJ008,012 UNITS WITH PARABLADE
ECONOMIZER — When the outdoor air is above the en-
thalpy control setting, and the room thermostat calls for cool-
ing, the compressor contactor no. 1 is energized to start
compressor no. 1 and the outdoor (condenser) fan motor. The
indoor (evaporator) fan motor is energized and the econo-
mizer damper moves to the minimum position. Upon further
call for cooling, compressor contactor no. 2 is energized, start-
ing compressor no. 2. After the room thermostat is satisfied
the damper will spring return to the fully closed position.
When the outdoor air is below the enthalpy control setting
and the thermostat calls for cooling, the economizer outdoor
air damper is opened proportionally to maintain between
50 and 56 F at the mixed air sensor. If outside air alone can-
not satisfy the cooling requirements, economizer cooling is
integrated with mechanical cooling and the second compres-
sor is locked out. When the room thermostat is satisfied, the
damper will spring return to the fully closed position.
HEATING, 50GJ006 UNITS WITH ECONOMIZER (If Ac-
cessory Heater is Installed) — Upon a call for heat through
W1, the IFC energizes to start the evaporator fan and the
economizer damper blade opens to the minimum position. If
the accessory two-position damper is used, the outdoor-air
damper opens to the minimum position whenever the evapo-
rator fan runs. If unit is equipped with 2 stages of heat, when
additional heat is needed a call is made through W2.
As space temperature approaches the heating temperature
set point, heating stages cycle off. Economizer or two-
position damper returns to fully closed position.
HEATING, 50GJ008,012 UNITS WITH ECONOMIZER (If
Accessory Heater is Installed) — When the room thermostat
calls for heat through terminal W1, the evaporator-fan con-
tactor and heater contactor no. 1 are energized. On units
equipped for 2 stages of heat, when additional heat is needed,
heater contactor no. 2 is energized through W2. The evaporator-
fan motor is energized, and the economizer damper moves
to the minimum position. If the two-position damper is used,
the outdoor-air damper opens to the minimum position when-
ever the evaporator fan opens. When the thermostat is sat-
isfied, the damper moves to the fully closed position.
SERVICE
When servicing unit, shut off all electrical power to unit
to avoid shock hazard or injury from rotating parts.
Cleaning —
Inspect unit interior at the beginning of each
heating and cooling season or as operating conditions
require.
EVAPORATOR COIL
1. Turn unit power off. Remove evaporator coil access panel.
2. If economizer or accessory two-position damper is in-
stalled, remove economizer/two-position damper by dis-
connecting economizer plug and removing mounting screws
(see Fig. 14 or 15). Refer to Accessory Economizer or
Two-Position Damper Installation Instructions for more
details.
3. Slide filters out of unit.
4. Clean coil using a commercial coil cleaner or dishwasher
detergent in a pressurized spray canister. Wash both sides
of coil and flush with clean water. For best results, back-
flush toward return-air section to remove foreign mate-
rial.
5. Flush condensate pan after completion.
6. Reinstall economizer and filters.
7. Reconnect wiring.
8. Replace access panels.
CONDENSER COILS — Inspect coils monthly. Clean con-
denser coils annually, and as required by location and outdoor-
air conditions.
Clean 2-row coils as follows:
1. Turn off unit power.
2. Remove top panel screws on condenser end of unit.
3. Remove condenser coil corner post. See Fig. 30 and 31.
To hold top panel open, place coil corner post between
top panel and center post. See Fig. 32 and 33.
4. Remove device holding coil sections together at return
end of condenser coil. Carefully separate the outer coil
section 3 to 4 in. from the inner coil section. See Fig. 34
and 35.
5. Use a water hose or other suitable equipment to flush down
between the 2 coil sections to remove dirt and debris. Clean
the outer surfaces with a stiff brush in the normal manner.
6. Secure the sections together. Reposition the coil sections,
and remove the coil corner post from between the top
panel and center post. Install the coil corner post and coil
center post, and replace all screws.
CONDENSATE DRAIN — Check and clean each year at
start of cooling season. In winter, keep drain dry or protect
against freeze-up.
FILTERS — Clean or replace at start of each heating and
cooling season, or more often if operating conditions require
it. Replacement filters must be same dimensions as original
filters.
OUTDOOR-AIR INLET SCREEN(S) — Clean screen(s) with
steam or hot water and a mild detergent. Do not use dis-
posable filters in place of screens.
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