Table of Contents
SERVICING
L1
L2
L3
L1
L2
L3
By the voltage readings we see that the imbalance rotated
or traveled with the switching of the incoming legs.
Therefore the imbalance lies within the incoming power
supply.
If the imbalance had not changed then the problem would
lie within the equipment. Check for current leakage,
shorted motors, etc.
S-2 Checking Wiring
HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing this unit. Multiple power
sources may be present. Failure to do so
may cause property damage, personal injury
or death.
1. Check wiring visually for signs of overheating,
damaged insulation and loose connections.
2. Use an ohmmeter to check continuity of any
suspected open wires.
3. If any wires must be replaced, replace with
comparable gauge and insulation thickness.
L1 - L2 = 240V
L1 - L3 = 227V
L2 - L3 = 238V
Rotate all 3 incoming
legs as shown.
L1 - L2 = 227V
L1 - L3 = 238V
L2 - L3 = 240V
S-3 Checking Thermostat, Wiring, And Anticipator
THERMOSTAT WIRE SIZING CHART
LENGTH OF RUN
25 feet
50 feet
75 feet
100 feet
125 feet
150 feet
S-3A Thermostat and Wiring
WARNING
Line Voltage now present.
With power ON, thermostat calling for cooling
1. Use a voltmeter to check for 24 volts at thermostat
wires C and Y in the unit control panel.
2. No voltage indicates trouble in the thermostat or
wiring.
3. Check the continuity of the thermostat and wiring.
Repair or replace as necessary.
Indoor Blower Motor
With power ON:
WARNING
Line Voltage now present.
1. Set fan selector switch at thermostat to "ON"
position.
2. With voltmeter, check for 24 volts at wires C and G.
3. No voltage indicates the trouble is in the thermostat
or wiring.
4. Check the continuity of the thermostat and wiring.
Repair or replace as necessary.
S-3B Cooling Anticipator
The cooling anticipator is a small heater (resistor) in the
thermostat. During the "off" cycle, it heats the bimetal
element helping the thermostat call for the next cooling
cycle. This prevents the room temperature from rising
too high before the system is restarted. A properly sized
anticipator should maintain room temperature within 1
1/2 to 2 degree range.
The anticipator is supplied in the thermostat and is not to
be replaced. If the anticipator should fail for any reason,
the thermostat must be changed.
MIN. COPPER WIRE
GAUGE (AWG)
18
16
14
14
12
12
47
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