36
Charging
5.8 Completing Installation
• Disconnect the hoses from the pressure ports. Replace the pressure port caps and tighten adequately to seal
caps.
Do not overtighten.
• Replace the service valve top caps finger-tight and then tighten with a wrench to adequately seal caps.
Do not
overtighten.
• Replace control box cover and service panel and install screws to secure panels.
• Restore power to unit at disconnect if required.
• Configure thermostat per the thermostat installation instructions and set to desired mode and temperature.
5.0 SYSTEM START-UP & REFRIGERANT CHARGING
6.0 SEQUENCE OF OPERATION
6.1
Sequence Of Operation
(-)ACL2120 (Two-Stage
Compressor)
1. When the room thermostat is set on “Cool”,
“Fan Auto”, and the temperature is higher than
the thermostat setting, the thermostat “Y1”
circuit closes and energizes the first speed of
the compressor contactor (CC1). Power to the
crankcase heater (CCH) will be de-energized by
the auxiliary contacts (AUX).
2. Simultaneously, the “G” circuit provides power to
the indoor blower motor circuit and starts indoor
air circulation through the evaporator coil.
3. When the discharge pressure increases to 450
psig, the contacts on the low ambient control
(LAC) (if installed) will allow supply power to start
the outdoor fan motors (ODF) which begins to
pull air through the condenser coils. The system
is now in the first stage cooling, operating at near
60 percent of full load capacity.
4. If the temperature at the thermostat continues to
increase, the thermostat “Y2” circuit closes and
energizes both speeds of the compressor which
is now full load capacity.
5. The system will continue cooling at maximum
capacity, as long as the room thermostat is
demanding full load and all safety device
contacts are closed. The low ambient control
(LAC) (if installed) will open and close, allowing
the outdoor fans to maintain discharge pressure
between 250 and 450 psig.
6. As the temperature at the thermostat drops
enough to satisfy “Y2”, the circuit will open and
de-energize the second compressor speed and
continues operating on the first speed of the
compressor.
7. When continued cooling satisfies the “Y1” circuit,
it will open and de-energize the compressor
contactor (CC1), stopping compressor operation
and closing the auxiliary contacts (AUX), which
energizes the crankcase heater (CH).
8. The thermostat “G” circuit will stop blower
operation.
6.2
Sequence Of Operation
(-)ACL2150, (-)ACL2180,
(-)ACL2240, (Tandem
Compressor)
1. When the room thermostat is set on “Cool”,
“Fan Auto”, and the temperature is higher
than the thermostat setting, the thermostat
“Y1” circuit closes and energizes the number
one compressor contactor (CC1) through the
closed cooling relay (R) contacts. Power to the
crankcase heater (CCH1) will be de-energized
by the auxiliary contacts (AUX-1).
2. Simultaneously, the “G” circuit provides power to
the indoor blower motor circuit and starts indoor
air circulation through the evaporator coil.
3. When the discharge pressure increases to 450
psig, the contacts on the low ambient control
(LAC) (if installed) will allow supply power to start
the outdoor fan motors (ODF) which begin to pull
air through the condenser coils. The system is
now in first stage cooling, operating at near fifty
percent of full load capacity.
4. If the temperature at the thermostat continues
to increase, the thermostat “Y2” circuit closes
and after a full 30 second delay, power passes
through the time delay control (TDC) and
energizes the number two compressor contactor
(CC2) through the second set of closed cooling
relay (R) contacts. Power to the crankcase
heater (CCH2) will be de-energized by the
auxiliary contacts (AUX-2).
5. The system will continue cooling at maximum
capacity, as long as the room thermostat is
demanding full load and all safety device
contacts are closed. The low ambient control
(LAC) (if installed) will open and close, allowing
the outdoor fans to maintain discharge pressure
between 250 and 450 psig.
6. As the temperature at the thermostat drops
enough to satisfy “Y2”, the circuit will open and
de-energize the compressor contactor (CC2),
stopping compressor operation and closing the
auxiliary contacts (AUX-2), which energizes the
Summary of Contents for ACL2120CAZ
Page 51: ...51...
Page 52: ...52 97B0135N01 CM 0218...
