Carrier 580PB - Manual (Page 13)

HEATING & COOLING
58ED,PB
Horizontal Gas-Fired Furnaces
27. Remove the flue box cover and flue box cover gasket
and remount them where the draft hood was located.
See Fig. 12. Do not glue gasket to cover plate.
28. Replace the draft hood support clip and the draft
hood where the flue box cover plate was located.
NOTE; All controls, wiring, draft hood and the
AG A lighting instruction plates must be located
on the same side of the furnace as the automatic
main gas valve. Reattach all wires to gas valve and
check against wiring diagram.
29. Elect}onic ignition models only: Reattach all wires
to the gas valve and the ignition cable to the ignition
control.
Check all wiring against the wiring diagram. Fig.
6 and 7.
30. After the furnace components have been reversed,
return to Step 3, Assemble Furnace Draft Hood and
proceed with remainder of installation.
START-UP AND ADJUSTMENT
Standing Pilot Models
OPERATIONAL CHECKOUT — The automatic gas
valve controls the flow of gas to both the pilot and
main burners. The manual valve built into the automatic
valve body has 3 positions- OFF, PILOT, and ON.
SEQUENCE OF OPERATION — The furnace operates
automatically. It is controlled by a thermostat which is
set at the desired temperature. When indoor temperature
/ drops below this setting, the thermostat turns on the
system.
When the thermostat calls for heat, power from the
transformer energizes the main gas valve (the pilot must
be lit already) and gas flows through the valve to the
burners. The pilot flame lights the burners.
A heat sensing switch automatically energizes the
blower when heat buildup is sufficient. The air is moved
by the blower over the heating element, thus warming it,
and it goes through the ducts to room registers.
When the thermostat is satisfied, the circuit is broken,
de-energizing the main gas valve and stopping gas flow
to the main burners.
The blower continues to run until the heat in the heat
exchanger is removed and then the sensing switch shuts
off the blower.
All forced air furnaces are equipped with a high
temperature limit switch which prevents the furnace
from overheating. If the furnace overheats for any
reason, the high temperature limit opens, breaking the
circuit to the gas valve. The blower motor continues to
run. The main burners cycle on limit until the fault is
corrected.
A WARNING
If overheating occurs, or if the gas supply fails to
shut off, shut off the manual gas valve to the furnace
before shutting off the electrical supply.
Electronic Ignition Models
OPERATIONAL CHECKOUT — The automatic gas
valve controls the flow of gas to both the pilot and main
burners. The manual valve built into the automatic valve
body has 2 positions: OFF and ON.
SEQUENCE OF OPERATION — The furnace operates
automatically. It is controlled by a thermostat which is
set at the desired temperature. When indoor temperature
drops below this setting, the thermostat turns on the
system.
When the thermostat calls for heat, power from the
transformer simultaneously energizes the pilot gas valve
(inside the main gas valve) and the spark igniter. After
the pilot flame is established, the electrode ceases to
spark and the flame sensing probe acts to energize the
main gas valve, permitting gas flow to the burners.
A heat sensing switch automatically energizes the
blower when heat buildup is sufficient. The air is moved
by the blower over the heating element, thus warming it,
and it goes through the ducts to room registers.
When the thermostat is satisfied, the circuit is broken,
de-energizing the main gas valve and stopping gas flow
to the pilot and main burners. The blower continues to
run until the heat in the heat exchanger is removed and
then the sensing switch shuts off the blower.
JUNCTION
BOX
Fig. 11 — Junction Box
(Model 58ED Shown)
FLUE BOX
COVER
(GASKET IS
UNDERNEATH)
Fig. 12 — Flue Box Cover
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
BookH 14 PC101 Catalog No 535-834 PrintedinUSA Form 58ED,PB-1SI Pg 13 6-85 Replaces: 58PB-1 SI