Fig.4-5
5.ELECTRICAL CONTROL DEVICES
10
REFRIGERANT CIRCUIT (Fig. 4-5)
All 13SEER units outdoor coils are multi-circuit. Refrigerent gas or liquid is uniformly distributed to from
4 to 10 circuits to improve heat transfer and reduce capacity losses due to pressure drops.
PROTECTION DEVICES
Protection for the unit begins with the installation of appropriate fuses or circuit breakers by the installing
OVERLOADS AND LIMITS
include the automatic reset internal overload in the fan motor and the compressor automatic reset
internal overload. Such controls are not serviceable but their operation may influence service
troubleshooting .For example, the compressor internal overload may stay open for several hours .A
THERMOSTATS
In the cooling mode, the thermostat calls for cooling by energizing the compressor contactor and the
indoor blower control. The indoor blower can operate continuously by setting the thermostat subbase fan
switch to the “ON” position.
subbase selection information found in the wiring diagram booklet.
various manual changeover, auto changeover and set-back thermostats or see the thermostat and
accessible by the consumer. Contact your local distributor for information on part numbers of
Thermostats are the most obvious control in the air conditioning system because these controls are
contractor. Breaker or fuse size is governed by the National Electrical Code and local code. AMP draw
Overloads protect against over-current or over-temperature conditions. Those located in the outdoor unit
requirements for each unit are found in the Specifications.
technician may incorrectly diagnose this as an open compressor winding.
RELAYS
COMPREESSOR CONTACTOR
contacts ,while others use 2-pole or 3-pole contacts.
compressor and outdoor fan.
OPTIONAL DELAYS AND KITS
before re-starting the compressor.
.
The coil uses 24 volts but the contacts carry line voltage .The heater contactor is a large relay,
which controls the compressor and the outdoor fan operation. Some contactor use single pole
Generally relays used in air conditioning use 24VAC coils. Contact voltage may be either low or line voltage.
Relays provide a method for control switching. Relays may switch either low(24VAC) or line voltage.
Single-pole contactors break only one side of the power feed to the compressor and outdoor fan. The other side
remains connected to the power source. The 2-pole or 3-pole contactor breaks power to all sides of the
CAUTION: WHEN THERE IS A SINGLE POLE CONTACTOR, ONE SIDE OF A 240 V.A.C.CIRCUIT
REMAINS HOT. THIS MEANS THAT THE WIRING IN THE HIGH VOLTAGE CIRCUIT MAY HAVE A
POTENTIAL OF 120V.A.C.TO GROUD. BEFORE SERVICING THE UNIT, ALWAYS TURN OFF
POWDER AT THE UNIT DISCONNECT SWITCH.
A Time-Delay in the compressor contactor lowcontrol circuit allows time for system pressure to equalize
This delay uses solid state circuitry to measure the time since the power was interrupted and is set for
approximately 3 minutes. It is not field adjustable. This is a delay on break timer.
Central Air Conditioner Model: Cooling Only, 13SEER units
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