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SERVICE
Perform
the procedures
outlined
below
periodically,
indicated.
To prevent injury or death due to electrical shock or contact
with moving parts, open unit disconnect
switch before ser-
vicing unit.
as
IMPORTANT:
When
a compressor
is removed
from this
unit, system refrigerant
circuit oil will remain in the com-
pressor. To avoid leakage of compressor
oil, the refrigerant
lines of the compressor
must be sealed after it is removed.
IMPORTANT:
All refrigerant
discharged
from
this unit
must be recovered
without exception. Technicians must fol-
low industry accepted guidelines and all local, state and fed-
eral statutes for the recovery and disposal of refrigerants.
IMPORTANT:
To avoid the release of refrigerant
into the
atmosphere,
the refrigerant
circuit of this unit must only be
serviced by technicians
who meet local, state and federal
proficiency
requirements.
Filters
--
Filters must be clean for maximum
performance.
Inspect filters every month under normal operating
conditions.
Replace when necessary.
I MPORTANT:
Units should
never be operated
without
a filter.
Water Coil
--
Keep all air out of the water coil. Check
open loop systems to be sure the well head is not allowing air
to infiltrate the water line. Always keep lines airtight.
Inspect heat exchangers
regularly, and clean more frequent-
ly if the unit is located in a "dirty" enviromnent.
Keep the heat
exchanger
full of water at all times. Open loop systems should
have an inverted P trap placed in the discharge
line to keep
water m the heat exchanger
during off cycles. Closed
loop
systems must have a minimum
of 15 psig during the SUlmner
and 40 psig during the winter.
Check P trap frequently for proper operation.
To avoid fouled
machinery
and extensive
unit clean-up,
DO NOT operate units without
filters in place. DO NOT
use
equipment
as
a
temporary
heat
source
during
construction.
Condensate Drain Pans
--
Check
condensate
drain
pans for algae growth twice a year. If algae growth is apparent,
consult a water treatment
specialist for proper chemical
treat-
ment. Applying
an algaecide every three months will typically
eliminate algae problems m most locations.
Refrigerant System
--
Verify air and water flow rates
are at proper levels before servicing. To maintain sealed circuit-
ry integrity, do not install service gages unless unit operation
appears abnormal.
Check to see that unit is within the superheat and subcool-
ing temperature
ranges shown in Tables 20-23. If the unit is not
within these ranges, recover and reweigh in refrigerant charge.
Compressor
_
Conduct
annual amperage
checks to en-
sure that amp draw is no more than 10% greater than indicated
on the serial plate data.
Fan Motors
_
All units have lubricated
fan motors. Fan
motors
should
never
be
lubricated
unless
obvious,
dry
operation
is suspected.
Periodic
maintenance
oiling is NOT
recolmnended
as it will result in dirt accumulating
in the excess
oil and cause eventual motor failure. Conduct annual dry oper-
ation check and amperage
check to ensure amp draw is no
more than 10% greater than indicated on serial plate data.
Condensate Drain Cleaning
--
Clean the drain line
and unit drain pan at the start of each cooling season.
Check
flow by pouring water into drain. Be sure trap is filled to main-
tain an air seal.
Air Coil Cleaning
_
Remove dirt and debris from evap-
orator coil as required by condition of the coil. Clean coil with
a stiff brush, vacuum
cleaner,
or compressed
air. Use a fin
comb of the correct tooth spacing when straightening
mashed
or bent coil fins.
Condenser Cleaning
_
Water-cooled
condensers
may
require cleaning
of scale (water deposits)
due to improperly
maintained
closed-loop
water systems.
Sludge build-up
may
need to be cleaned
in an open water tower
system
due to
induced contaminants.
Local
water conditions
may cause excessive
fouling
or
pitting of robes. Condenser
robes should therefore be cleaned at
least once a year, or more often if the water is contaminated.
Proper
water treatment
can minimize
robe fouling
and
pitting.
If such conditions
are anticipated,
water
treatment
analysis is recolmnended.
Refer to the Carrier System Design
Manual, Part 5, for general water conditioning
information.
Follow all safety codes. Wear safety glasses and rubber
gloves when using inhibited hydrochloric acid solution.
Observe and follow acid manufacturer's instructions.
Clean condensers with an inhibited hydrochloric acid solu-
tion. The acid can stain hands and clothing, damage concrete,
and, without inhibitor, damage steel. Cover surroundings to
guard against splashing. Vapors from vent pipe are not harmful,
but take care to prevent liquid from being carried over by the
gases.
Warm solution acts faster, but cold solution is .just as effec-
tive if applied for a longer period.
GRAVITY FLOW METHOD-
Do not add solution faster
than vent can exhaust the generated gases.
When condenser is full, allow solution to remain overnight,
then dram condenser and flush with clean water. Follow acid
manufacturer's instructions. See Fig. 38.
FORCED CIRCULATION METHOD-
Fully open vent
pipe when filling condenser. The vent may be closed when
condenser is full and pump is operating. See Fig. 39.
Regulate flow to condenser with a supply line valve. If
pump is a nonoverloading type, the valve may be fully closed
while pump is running.
For average scale deposit, allow solution to remain m con-
denser overnight. For heavy scale deposit, allow 24 hours.
Drain condenser and flush with clean water. Follow acid manu-
facturer's instructions.
45
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