Bryant 451A - Manual (Page 6)

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" wall thickness - south of 40 ° N. latitude
3/8" wall thickness - north of 40° N. latitude
D. HEIGHT OF COIL
ABOVE ABSORPTION UNIT
Maximum vertical distance from chiller outlet to
top of coil is 22 feet for both sizes. For greater
heights, a greater pumping head is required. In­
creasing the pipe size will not help.
E. WATER COIL CONNECTIONS
1. If coil is located in warm air stream, do not
connect polyethylene pipe directly to coil. Connect
a minimum of 24 inches 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, pre­
cautions must be taken to provide for water expan­
sion. The connecting polyethylene plastic pipe
acts as an expansion vessel if there is enough foot­
age of this pipe in the heated space (space not
subject to freezing). The following table shows
the minimum lengths (total inlet and outlet) of
plastic piping of various diameters that are re­
quired for both sizes of coils to provide adequate
expansion volume.
Nominal Pipe Size
Inches
Length of Plastic Pipe
in Feet
Size 36 Size 54
% 24 56
1 15 35
V k 8.5 20
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.
Ill, ELECTRIC CONNECTIONS
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
conditioner.
3. Provide a fused disconnect switch within easy
reach of the absorption unit.
Size 36 - use 30 amp. Standard fuse or 15 amp.
fusetron.
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. Figure 6 is the Wiring Diagram. Do not fasten
power leads to hot tubing since wire insulation
could be damaged and a short circuit could result.
6. Disconnect pump electrical leads at terminals
6 and 7 in control box before energizing unit when
ready to check field wiring.
Do not operate the
pump dry.
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
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.
The gas connection to the unit is made at the com­
bination regulator-shut-off. On the size 36 use a
V 2 " X 3" nipple and then a elbow. The supply
pipe enters the knockout on the other end of the
unit and will then be lined
Up for final connection
if the nipple and elbow are used as described. On
the size 54 use aVi" x 2 "nipple and then a^/i" x
reducing ell and 3/4 inch pipe.
EH 451
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