Bryant 108-451 - Manual (Page 7)

IX. PURGE NON-CONDENSIBLES FREEZING WEATHER PROTECTION
Purging is accomplished through valves A on inlet
tanks and valves D on purge pots. Each refrigera­
tion circuit must be checked.
Operate unit for a minimum of 15 minutes. While
still operating, proceed as follows:
1. Attach adapter and purge line to valve A.
2. Run purge line to bucket of water.
3. Remove cap and open valve A about 1/8 to 1/4
turn.
4.
If non-condensibles are present, bubbles will
rise to the surface of the water in the bucket.
5. Leave valve A open as long as bubbles rise
to the surface of the water. When non-condensibles
are removed the bubbles will cease as ammonia
will be absorbed into the water.
6. Close valve A.
7. Open valve D about 1/8 turn. Usually there will
be some solution trapped in the valve body, and this
solution will be released as soon as the valve is
opened.
8. If non-condensibles are present they will follow
the initial surge of solution. When solution reappears
in quantity, the non-condensibles trapped in the
purge pot have been released.
9. Close valve D.
10. Repeat procedure for other circuit.
The installation should now be complete.
Gas Air Conditioner
The Gas Air Conditioner has built-in freeze pro­
tection sufficient to protect the chiller and pump
plus a small amount of external hard (non-plastic)
pipe as shown in Figure 2.
Chilled Water Pipes
If hard pipe (non-plastic) is used for the chilled
water lines, it will be necessary to drain the lines
or add anti-freeze. The recommended anti-freeze is
methanol (uninhibited methyl alcohol). Since the
fluid will not be pumped, only enough methanol is
required to form slush. Add one gallon-of methanol
for each 20 gallons of water or fraction thereof,
and circulate 10 minutes. The chilled water additive
(Borax) must be used in the same proportion as
indicated in Section V when anti-freeze treatment
is required.
Chilled Water Coil
If water coil is subject to freezing temperatures,
it will be necessary to protect the coil by the ad­
dition of anti-freeze. Chilled water coils cannot
be completely drained. Add one gallon of methanol
for each 20 gallons of water or fraction thereof,
and circulate 10 minutes. The chilled water addi­
tive (Borax) must be used in the same proportion
as indicated in Section V when anti-freeze treatment
is required.
Operation at Freezing Temperatures
If the air conditioning system is to operate under
freezing conditions, it will be necessary to add
methanol in the amount required to protect to the
lowest outdoor temperature. Consult your Bryant
distributor for recommended procedure.
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