Carrier 58PAV - Manual (Page 16)

1. Check Primary limit control.
This control shuts off the combustion control system
and energizes the circulating-air blower motor if the
furnace overheats.
The preferred method of checking the limit control is to
gradually block off the return air after the furnace has
been operating for a period of at least 5 minutes. As
soon as the limit has shutoff the burners the retum-air
opening should be unblocked. By using this method to
check the limit control, it can be established that the
limit is functioning properly and will “operate” if there
is a motor failure.
2. Check draft safeguard switch.
The purpose of this control is to permit the safe shut­
down of the furnace during certain blocked vent
conditions.
a. Disconnect power to furnace and remove vent con­
nector from furnace outlet collar. Be sure to allow
time for vent pipe to cool down before removing.
b. Set room thermostat above room temperature and
restore power to furnace.
c. After normal startup, allow furnace to operate for 2
minutes, then block (100%) flue outlet. Furnace
should cycle off within 2 minutes.
d. Remove blockage and reconnect vent pipe to fur­
nace outlet coUar.
e. Wait 5 minutes and then reset draft safeguard
switch.
3. Check flow-sensing switch.
This control proves operation of draft inducer blower.
a. Turn off 115-volt power to furnace. ".. .
b. Remove control door and disconnect inducer motor
lead wires from wire harness.
c. Turn on 115-volt power to furnace. ^ ,
d. Close thermostat switch as if making normal
furnace start. If the hot surface ignitor does not
glow, then the flow-sensing switch is functioning
properly.
e. Turn off 115-volt power to furnace.
f. Reconnect inducer motor wires, replace control
door, emd turn on 115-volt power.
F. Check List
1. Put away tools, instruments, and cleanup debris.
2. Verify manual reset switches have continuity.
3. Blower and control access doors are properly installed.
4. Cycle test furnace with room thermostat.
5. Check operation of accessories per manufacturer’s
instructions.
6. Review User’s Guide with owner.
7. Leave literature packet near furnace.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
^°°^| 1 I ^ PC 101 Catalog No. 565-913 Printed in U.S.A. Form58PA-1SI Pg 16 5-90
Tab I6al8a
Replaces: New