Bryant 108-451 - Manual (Page 4)

5. Figures 3 & 4 are the Wiring Diagrams for the
natural gas unit. Figures 5 8s 6 are the Wiring Dia­
grams for an LPG unit.
6. Disconnect pump electrical lead at terminal 7
in front control box before energizing unit when
ready to check field wiring.
Do not operate the
pump dry.
PILOT
The natural gas unit is equipped with two reignition
type pilots (one pilot in each generator). The pilots
will light automatically when supplied with gas and
are electrically energized. The circuit is arranged
to light the pilots sequentially. Several minutes
must be allowed for the first pilot to ignite and
make contact before second pilot will be energized.
IV. GAS CONNECTIONS
Consult local gas company before making any gas
connections. In case of conflict with this instruc­
tion, local requirements should be followed.
Before selecting the size and type of pipe that is
to be used for installing the absorption unit, be
sure to check with local gas company for the neces­
sary information. The size of the gas pipe to be
used between meter and unit will depend upon the
length of run and the allowable pressure loss estab­
lished by the utility.
The gas connections to the unit are made at the
1/2 inch combination regulator-shut offs at each of
the two generators. The gas supply pipes enter the
unit through openings located at lower left rear and
lower right rear of unit. Install 1/2 inch ground
joint unions and 1/2 x 3/4 inch ells adjacent to
each combination regulator-shut off using two 1/2
inch X close nipples. The gas supply pipe from the
meter should terminate at the rear of the unit with a
tee. Install 3/4 inch pipe from this tee through the
openings in the rear casing to the 1/2 x 3/4 inch
ells adjacent to the regulator-shut offs at each
generator.
A. wrench-type shut-off valve should be installed in
the gas supply line within sight of, and convenient
to, the 451. It is recommended that ground joint
unions be installed in the gas supply piping just
outside the unit.
Joint compound (pipe dope) which is resistant to
the action of liquefied petroleum gases should be
applied sparingly and only to the male threads of
the joints.
After gas pipe connections have been made, purge
the lines and check for leakage. Use a soap and
water solution or other such material. Turn off
power supply to unit when purging the lines to
prevent glow coils in reignition pilots from being
energized. Never use matches, candles, flame or
other source of ignition to check leakage.
To manually light the pilots use the procedure out­
lined on the Lighting Instruction Plate attached to
generators. The pilot flame should be soft blue in
color. The flame should be of sufficient length to
provide good impingement on the unimetal element
of the Bryant pilot. Flame should extend upward
between the carry-over ports of the two adjacent
burners.
If the pilot flame does not have the appearance
described above, it may be adjusted by means of
the manual pilot shut-off valve which 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 desired
appearance. Replace screw cap.
V. CHARGING THE SYSTEM WITH WATER
Caution: Do not run the pump dry. Freezing con­
ditions will not damage the pump; however, do not
attempt to operate the pump when chiller or chilled
water lines are frozen.
1. Turn off main manual gas shut-off valve.
2. Remove the filler caps located on top of both
chiller tanks.
3. Disconnect water line at chiller inlet. (When
installing the chilled water lines, it is advisable to
leave this connection open until lines have been
flushed.)
4.
Fill tanks with tap water through the filler
opening of one tank until the distributor pans are
covered with water. A garden hose is useful for this
filling operation.
5. Start pump. Continue to supply water to the tank
and operate pump until all foreign matter has beeii
flushed from the lines. Then remove hose.
Note: If water does not circulate when the pump
is started, air may be trapped in the pump. Bleed
the air from pump through the 1/8 inch slotted head
108/451 -4-