Carrier 50PSH Heat Pump User Manual


 
48
SERVICE
Perform the procedures outlined below periodically, as
indicated.
Filters — Filters must be clean for maximum performance.
Inspect filters every month under normal operating conditions.
Replace when necessary.
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” environment. 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 in the heat exchanger during off cycles. Closed loop
systems must have a minimum of 15 psig during the summer
and 40 psig during the winter.
Check P trap frequently for proper operation.
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 in 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 20-30. 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 opera-
tion is suspected. Periodic maintenance oiling is NOT recom-
mended as it will result in dirt accumulating in the excess oil
and cause eventual motor failure. Conduct annual dry opera-
tion 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 tubes. Condenser tubes should therefore be cleaned at
least once a year, or more often if the water is contaminated.
Proper water treatment can minimize tube fouling and
pitting. If such conditions are anticipated, water treatment
analysis is recommended. Refer to the Carrier System Design
Manual, Part 5, for general water conditioning information.
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 drain condenser and flush with clean water. Follow acid
manufacturer’s instructions. See Fig. 36.
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. 37.
Regulate flow to condenser with a supply line valve. If
pump is a non overloading type, the valve may be fully closed
while pump is running.
For average scale deposit, allow solution to remain in con-
denser overnight. For heavy scale deposit, allow 24 hours.
Drain condenser and flush with clean water. Follow acid manu-
facturer’s instructions.
WARNING
To prevent injury or death due to electrical shock or contact
with moving parts, open unit disconnect switch before ser-
vicing unit.
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.
IMPORTANT: Units should never be operated without
a filter.
CAUTION
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.
CAUTION
Follow all safety codes. Wear safety glasses and rubber
gloves when using inhibited hydrochloric acid solution.
Observe and follow acid manufacturer’s instructions.