Checking Voltage; Checking Wiring; Checking Thermostat, Wiring And Anticipator; S-3A Thermostat And Wiring - Intertek ACVC96 Service Instructions Manual

SERVICING
S-1 CHECKING VOLTAGE
HIGH VOLTAGE
D ALL
ISCONNECT POWER BEFORE SERVICING OR
CHANGING ANY ELECTRICAL WIRING.
F
SOURCES MAY BE PRESENT. AILURE TO DO SO MAY CAUSE
PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
1. Remove the burner door.
2. Remove cover from the Junction Box and gain access to
incoming power lines.
With Power ON:
WARNING
L
INE VOLTAGE NOW PRESENT
3. Using a voltmeter, measure the voltage across the hot
and neutral connections.
NOTE: To energize the furnace, the Door Interlock Switch
must be engaged at this point.
4. No reading - indicates open wiring, open fuse, no power,
or faulty Door Interlock Switch from unit to fused dis-
connect service. Repair as needed.
5. With ample voltage at line voltage connectors, energize
the furnace blower motor by jumpering terminals R to G
on the integrated ignition control.
6. With the blower motor in operation, the voltage should
be 115 volts ± 10 percent.
7. If the reading falls below the minimum voltage, check
the line wire size. Long runs of undersized wire can cause
low voltage. If wire size is adequate, notify the local power
company of the condition.
8. After completing check and/or repair, replace Junction
Box cover and reinstall the service panel doors.
9. Turn on electrical power and verify proper unit operation.
S-2 CHECKING WIRING
WARNING
D ALL
ISCONNECT POWER BEFORE SERVICING.
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 AWM, 105°C.
2/64 thick insulation of the same gauge or its equivalent.
WARNING
M
ULTIPLE POWER
CHECKING THERMOSTAT, WIRING
AND ANTICIPATOR

S-3A THERMOSTAT AND WIRING

WARNING
D ALL
ISCONNECT POWER BEFORE SERVICING.
1. Remove the blower compartment door to gain access to
the thermostat low voltage wires located at the furnace
integrated control module terminals.
2. Remove the thermostat low voltage wires at the furnace
control panel terminal board.
3. Jumper terminals R to W (or W1 and W2 for two-stage
models) on the integrated ignition control.
With Power On (and Door Interlock Switch closed):
WARNING
L
INE VOLTAGE NOW PRESENT
4. Induced Draft Motor must run and pull in pressure switch.
5. If the hot surface ignitor heats and at the end of the
ignitor warm-up period the gas valve opens and the burn-
ers ignite, the trouble is in the thermostat or wiring.
6. With power off, check the continuity of the thermostat
and wiring. Repair or replace as necessary.
If checking the furnace in the air conditioning mode, pro-
ceed as follows.
7. With power off, Jumper terminals R to Y (or Y1 or Y2 for
two-stage models) to G.
8. Turn on the power.
9. If the furnace blower motor starts and the condensing
unit runs, then the trouble is in the thermostat or wiring.
Repair or replace as necessary.
10. After completing check and/or repair of wiring and check
and/or replacement of thermostat, reinstall blower com-
partment door.
11. Turn on electrical power and verify proper unit operation.

S-3B HEATING ANTICIPATOR

On older thermostats, the heating anticipator is a wire wound
adjustable heater which is energized during the "ON" cycle
to help prevent overheating of the conditioned space.
The anticipator is a part of the thermostat and if it should fail
for any reason, the thermostat must be replaced.
The heating anticipator setting for furnaces covered in this
manual is 0.70 Amps.
Modern thermostats do not have this type of heat anticipa-
tor. Many have a selector switch to adjust the number of
cycles per hour
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