Bryant Gas Air 393U - Manual (Page 10)

ELECTRICAL CONNECTIONS
START-UP AND ADJUSTMENT
All electrical connections are to be made in accord­
ance with the local codes governing such wiring.
A permanent, live, separately fused electric power
supply, complete with manual switch, should be
provided for the furnace.
The room thermostat should be located where it will
be in the natural circulating path of room air. Avoid
locations where the thermostat would be exposed to
cold air infiltration, drafts from windows, doors, or
other openings leading to the outside; or exposure
to air currents from warm or cold air registers; or to
exposure where the natural circulation of the air is
cut off such as behind doors, above or below man­
tels, shelves, etc.
The thermostat should not be exposed to heat from
nearby
radiators, fireplaces, radios, televisions,
lamps, or rays from the sun. Nor should the thermo­
stat be mounted on a wall containing pipes or warm
air ducts, or a flue or vent which could affect its
operation and prevent it from properly controlling
the room temperature. Any hole in the plaster or
panel through which the wires pass from the thermo­
stat should be adequately sealed with suitable
material to prevent drafts from affecting the thermo­
stat.
INSTALLING THE UNIT
Sizes 50, 80,100 & 125 for natural gas are complete­
ly assembled at the factory. All other units are
shipped fully assembled with the exception of the
manual main shut-off valve, pilot feed tube, and
pilot gas filter, which are shipped loose. The filter
is snpplied for manufactured gas units only.
The order to be followed in setting the unit in place
and making all the necessary connections (gas,
electric, venting, duct work, etc.) is left to the
discretion of the installer. Recommendations listed
on pages 5 to 7 of this instruction should be fol­
lowed. When making the gas piping installation as
described on page 6, assemble the pilot manual shut
off valve in the threaded boss provided at the inlet
side of the main manual gas shut-off valve. If the
installation is for manufactured gas, install the gum
filter between the two valves. Cut the pilot feed
tube to the desired length and connect the pilot
manual shut-off to the pilot.
For furnaces with D2 or D5 controls the pilot feed
tube is connected to the pilot relay.
Check to be sure that all connections have been
properly made, then proceed as follows:
Light the pilot using the procedure outlined on the
Lighting Instruction Plate attached to the furnace.
However, when lighting the pilot for the first time,
perform the following additional steps:
1. If the supply line was not purged prior to con­
necting the furnace, it will be full of air. Since it
would take a long time to vent this air through the
small pilot port, it is recommended that the pilot
supply line be disconnected at the pilot shut-off
valve and the supply line be allowed to purge until
the odor of gas is detected.
Never purge gas lines
into the combustion chamber. Immediately upon
detection of gas odor, re-connect the pilot supply
tube. Allow 5 minutes to elapse and light the pilot
in accordance with the instructions on the front of
the furnace.
2. The pilot flame should be soft blue in color.
a. For city gas controls (D4) this flame should be
of sufficient length to provide good impingment on
the mono-metal element of the Bryant pilot. Flame
should extend upward between the carry-over ports
of the two adjacent burners.
b. For LP gas controls (D2), the flame should
surround the tip of the thermocouple element of the
pilot and extend downward to include 3/8 inch to
1/2 inch of the thermocouple. The flame must never
come in contact with any other part of the thermo­
couple or its lead wire. The flame lies under the
carry-over ports of the burners and merges with the
carry-over flames. D5 controls have the same pilot.
3. If the pilot flame does not have the appearance
described above, it may be adjusted by means of the
manual pilot shut-off valve.
a. If the valve is equipped with an adjustable
screw, turn the handle to the full-open position and
remove the screw cap on the valve handle, thus
exposing the adjustable screw. Turn adjusting screw
until flame has the desir-ed appearance. Replace
screw cap.
b. If the valve is not equipped with the adjusting
screw, adjustment of the flame is effected by alter­
ing the position of the valve handle.
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