Bryant 450D - Manual (Page 4)

II. CHILLED WATER LINES (cont’d.)
C. INSULATION
1. Insulate supply and return lines separately.
2. Material should be of good quality and be covered
with a good vapor barrier. Armaflex or equivalent
is recommended.
Wall thickness:
1/2” - south of 40° N. latitude
3/8” - north of 40° N. latitude
D. HEIGHT OF COIL ABOVE ABSORPTION UNIT
Maximum vertical distance from chiller outlet to top
of coil is 22 ft. for both sizes. For greater heights,
a greater pumping head is required. Increasing the
pipe size will not help.
E. WATER COIL CONNECTIONS
1. If coil is located in warm air stream, do not con­
nect polyethylene pipe directly to coil. Connect
a minimum of 24” copper or galvanized pipe to
both the coil inlet and outlet. Then connect the
plastic pipe to these nipples.
2. On installations where the outside piping freezes.
and the coil is in a heated air stream, precau­
tions must be taken to provide for water expan­
sion. The connecting polyethylene plastic pipe
acts as an expansion vessel if there is enough
footage of this pipe in the heated space (space
not subject to freezing). The following table
shows the minimum lengths (total inlet and out­
let) of plastic piping of various diameters that
are required for both sizes of coils to provide
adequate expansion volume.
Nominal Pipe Size
Length of Plastic Pipe
Unit Size
36 54
3/4 24 56
1 15 35
1-1/4 8.5 20
1-1/2 6.5 14.5
If the total plastic chilled water line footage in
the heated space is not as long as the minimum
values shown in the table, tee a vertical pipe of
sufficient volume into either of the coil connec­
tions to provide for expansion, or the line should
be drained.
F. LEAK CHECK
Water should be added to the chiller, pump operated,
and each joint checked for leakage. Do not add the
chemical additive (shipped in container stored in
chiller tank) to the water until after leak check is
complete. It is convenient to check for leakage
when charging the system with water. See Section V.
III. ELECTRIC CONNECTIONS
(»• J
1. Make all electric connections in accordance with the
National Electrical Code and any local ordinances
or codes that might apply.
2. Provide a separate power supply for the air condi­
tioner.
3. Provide a fused disconnect switch within easy reach
of the absorption unit.
Size 36 -use 30 amp. standard fuse or 15 amp. fuse-
tron. Size 54-use 35 amp. standard fuse or 20 amp.
fusetron.
4. The absorption unit is shipped fully wired from the
factory. Connection of 115V power and low voltage
connection to the thermostat control are required in
the field. Before proceeding, inspect factory wiring
for loose connections which may have resulted
during shipment.
5. Figures 3 and 4 are wiring diagrams.
IV. GAS CONNECTIONS
Consult local gas company before making any gas con­
nections. In case of conflict with this instruction,
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 necessary information.
The size of the gas pipe to be used will depend upon
the length of run and the allowable .pressure loss
established by the utility.
A wrench-type shut-off valve should be installed in the
gas line within sight of, and convenient to, the 45OD.
Provide a ground joint union inside the unit case and
upstream of the main gas supply regulator.
Install a drip leg trap in the gas supply riser leading
to the unit.
After gas pipe connections have been made, purge the
lines and check for leakage. Use a soap and water solu­
tion or other such material. Never use matches, candles,
flame or other source of ignition to check leakage.
PILOT
The pilot assembly is equipped with a fixed orifice
designed to give correct input at 3” w.c. gas pressure.
The pilot supply line is equipped with a regulator and
factory adjustment of this regulator should be satis­
factory in all cases. The manual shut-off valve for the
pilot gas supply is incorporated in this regulator.
To light pilot:
1. Shut off main electric power and remove lower
front panel from unit.
2. Be sure manual shut-off valve to the burners is
closed. Also close the manual shut-off valve to
the pilot.
3. Wait five minutes.
4. Open manual shut-off valve to pilot, and light
pilot with taper through the pilot hole on front of
generator.
E H 4 5 0 - 4 -