Bryant Model 378 - Manual (Page 8)

Winter Shut-Down Protection (continued) MAINTENANCE
Winter shut-down protection can be provided as
follows:
1. With the pump circulating water with additive
(borax), add one gallon of methanol (uninhibited
methyl alcohol) for each 20 gallons of water or
fraction thereof, and circulate for ten minutes.
2. It is not necessary to drain the system,
3. Tag the unit to show methanol has been added.
4. Determine the correct amount of methanol re­
quired as follows:
a. Estimate the system water capacity in gal­
lons from table below. Multiply the length of
pipe in feet by the gallons in one foot; then
add the gallons of water in chiller, or chil­
lers, and coil.
b. Water Capacity Table:
36-450 Chiller.....................
54-450 Chiller . . . . .
36W-378 or 54W-378 Coil
90W-378 or 108W-378 Coü
1 ft. of 3/4 inch pipe______
1 ft. of 1 inch pipe . . .
1 ft. of 1 -1/4 inch pipe.
1 ft. of 1 -1/2 inch pipe.
Water Capacity Gallons
5
8
1.5
3.0
.03
.05
.08
.12
c. With the pump operating, adjust the water
operating level in the chiller.
Summer Operation
In general, it is recommended that the methanol be
flushed from the chilled water system for summer
operation. The presence of methanol in the chilled
water will reduce the capacity with a corresponding
increase in operating cost. However, the reduction
in capacity resulting from the 5% solution of meth­
anol is small (less than 1%) and the methanol may be
left in the system.
If the system is drained, flushed, and refilled with
water, be sure to add one box of chilled water ad­
ditive (borax) for each 20 gallons of water or frac­
tion thereof in the system.
Note: The above explanation covers only the normal
winter shut-down protection. If, for any reason, the
gas air conditioner must operate when the outdoor
temperatures are below freezing, it will be neces­
sary to prepare the chilled water system for the
minimum temperature. Consult your Bryant distri­
butor for special procedures to follow.
LUBRICATION
Blower Motor - if equipped with oil cups, oil motor
bearings with SAE10-20 non-detergent oil each
heating and cooling season. Use approximately six
drops for each bearing. Some motors are equipped
with bearings of a permanently lubricated type and,
therefore, need no further oiling.
Blower Bearings -are of the permanently lubricated
type and, therefore, need no further oiling.
Combustion Air Blower Motor — (located in control
compartment). Oil motor bearings with SAE 10-20
non-detergent oil each heating season. Use approxi­
mately three drops for each bearing.
Air Filter
Periodically inspect air filters. Replace when dirty
with filters of the same size (see marking on fil­
ters), making sure that arrows on edge of filter
point in direction of air flow (toward blower).
Excessively dirty filters reduce furnace efficiency.
Cleaning the Unit
1. Be sure main line disconnect switch is in the
“off”^ position. Tag with suitable warning label.
2. Turn manual gas and pilot valve to “off” posi­
tion.
3. Remove upper and lower front access panels.
4. Disconnect pilot and escapement tubing.
5. Remove burners.
6. Remove screws holding horizontal dividing panel
and flue collector in place,
7. Tip dividing panel and flue collector up and
back to give access to flue outlets.
8. Remove flue baffles.
9. Clean flue passages with suitable brush.
10. Re-assemble furnace by reversing the above
procedure, making sure all seals are properly re­
placed.
See following pages for Wiring Diagrams.
EH 378 - 8 -