71
b. Remove thermostat from subbase or from wall.
c. Connect an amp. meter as shown in Fig. 63 across the R
and W subbase terminals or R and W wires at wall.
d. Record amp. draw across terminals when furnace is in low
heat and after blower starts.
e. Set heat anticipator on thermostat per thermostat
instructions and install on subbase or wall.
f. Turn SW1--2 switch OFF.
g. Install blower door.
2. Electronic thermostat: Set cycle rate for 3 cycles per hr.
Check Safety Controls
The flame sensor, gas valve, and pressure switch were all checked
in the Start--up procedure section as part of normal operation.
1. Check Main Limit Switch
This control shuts off combustion system and energizes air--
circulating blower motor, if furnace overheats. By using this
method to check limit control, it can be established that lim-
it is functioning properly and will operate if there is a re-
stricted return--air supply or motor failure. If limit control
does not function during this test, cause must be determined
and corrected.
a. Run furnace for at least 5 minutes.
b. Gradually block off return air with a piece of cardboard or
sheet metal until the limit trips.
c. Unblock return air to permit normal circulation.
d. Burners will re--light when furnace cools down.
2. Check Pressure Switch(es)
This control proves operation of the draft inducer blower.
a. Turn off 115--v power to furnace.
b. Disconnect inducer motor lead wires from wire harness.
c. Turn on 115--v power to furnace.
d. Set thermostat to “call for heat” and wait 1 minute. When
pressure switch is functioning properly, hot surface igniter
should
NOT
glow and control diagnostic light flashes a
status code 32. If hot surface igniter glows when inducer
motor is disconnected, shut down furnace immediately.
e. Determine reason pressure switch did not function proper-
ly and correct condition.
f. Turn off 115--v power to furnace.
g. Reconnect inducer motor wires, replace door, and turn on
115--v power.
h. Blower will run for 90 sec before beginning the call for heat
again.
i. Furnace should ignite normally.
Checklist
1. Put away tools and instruments. Clean up debris.
2. Verify that switches SW1--1 and SW1--6 are
OFF
and other
setup switches are set as desired. Verify that switches
SW1--7 and SW1--8 for the blower
OFF DELAY
are set as
desired per Table 19.
3. Verify that blower and control doors are properly installed.
4. Verify that there are no unsealed openings in the blower
shelf or casing.
5. Cycle test furnace with room thermostat.
6. Check operation of accessories per manufacturer’s instruc-
tions.
7. Review Owner’s Manual with owner.
8. Attach literature packet to furnace.
Содержание 59TP6B
Страница 41: ...41 A190044 Fig 39 Example of Variable Speed Furnace Control ...
Страница 72: ...72 A190070 Fig 64 Service Label Information ...
Страница 90: ...90 A190072 Fig 73 Wiring Diagram ...