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Maintenance Procedures
a. Verify that the pressure controls (low pressure and
high pressure switches) are "cutting in" and "cutting
out" at the appropriate pressures.
b. Verify refrigerant charge by recording the superheat
and sub-cooling temperatures.
c. Observe head pressure for signs of improper
condensing from clogged strainers, or a modulating
expansion valve issue.
12. Check compressor motor amperage draws and voltage
supplies and maintain a record of those values. Verify
that they are within the name plate rating. Also, check
for voltage imbalance. The heat pump's phase monitor
will open if the voltage imbalance exceeds 4%.
13. Check for chattering, excessive wear or burned
contacts on motor starters. Replace contacts, if in
doubt. It is recommended to replace contactors every
5-6 years.
Annually
The annual heat pump maintenance inspection is critical to
the long-term performance of the Heat Pump. Whether a
heat pump has a service life of 15 years or 30 years is
almost entirely dependent upon how consistently and how
diligently the annual maintenance inspection and tasks are
performed. The annual event is a comprehensive
inspection that examines all aspect of the heat pump to
identify and repair small problems before they can become
major issues that damage a heat pump and require
significant repair or refurbishment.
1. Inspect all electrical connections for damage and
ensure terminals are tight. Inspect all contactors for
pitting and corrosion and replace as necessary. It is
recommended to replace contactors every 5-6 years.
WARNING
Hazardous Voltage!
Failure to disconnect power before servicing could
result in death or serious injury.
Disconnect all electric power, including remote
disconnects before servicing. Follow proper lockout/
tagout procedures to ensure the power can not be
inadvertently energized. Verify that no power is
present with a voltmeter.
2. Inspect fuses to ensure they are secure, of correct
amperage ratng, undamaged and functioning.
3. Energize each compressor and check refrigerant
pressures, signs of overheating, and oil leaks. Check
for noises and for leaks with an electronic or bubble
leak detector. Inspect flared fittings, refrigeration
gauges, compressor connections, braze joints,
pressure switches, and access ports on Schrader
valves.
50
WARNING
Refrigerant under High Pressure!
Failure to follow instructions below could result in an
explosion which could result in death or serious
injury or equipment damage.
System contains refrigerant under high pressure.
Recover refrigerant to relieve pressure before
opening the system. See unit nameplate for
refrigerant type. Do not use non-approved
refrigerants, refrigerant substitutes, or refrigerant
additives.
4. De-energize each compressor and inspect terminals for
pitting, corrosion, and loose connections.
5. Inspect that the oil level is visible in each compressor
and not discolored. Annual oil samples should be taken
to be analyzed for destructive acids, corrosive
materials, or metal deposits.
6. Inspect and record the compressor amperage draws
and voltage.
7. Record water/glycol mixture flow to ensure it meets
design specifications.
8. Tighten rotalock nuts at the compressors. The
recommended torque is 80 lbf for 2 inch and larger and
60 lbf for rotalock nuts smaller than 2 inch.
9. Inspect all copper lines and control capillary tubing to
ensure that the lines are separated and not vibrating
against one another or the frame or housing.
10. Ensure all refrigeration lines are properly supported to
prevent vibration from causing premature failure of
copper piping.
11. Inspect all insulation on piping and control sensors.
Repair and replace as necessary.
12. Inspect entire plumbing system for leaks.
13. Review logged alarms and look for repetitive trends.
The heat pump can retain the previous 200 alarms with
time and date of occurrence.
14. If equipped, inspect crankcase heaters to verify proper
operation.
15. Sample refrigerant to analyze for moisture or acid.
16. Inspect operating pressures and temperatures and
ensure the heat pump has a full refrigerant charge.
Maintenance Tasks
The maintenance tasks described herein present the basic,
minimal, steps required to successfully complete a task.
Local policies and protocols may require more elaborate
procedures with additional checks and inspections.
Inspection Methods
Appropriate inspection for modern heat pumps can be
described as "hands on." Where possible and appropriate,
visual inspection should include touching the component or
ARTC-SVX006A-EN
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