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P/N SCM2-0111
Model
SCM
Air to Water Heat Pump — Installation, Operation & Maintenance Manual
Section 9: Maintenance
Glycol/water mixture
The water system must contain a mixture of inhib-
ited glycol and water with thermal protection suf-
ficient for the coldest expected temperature for the
installation. The inhibitor level can degrade over
time, and may need to be adjusted periodically.
The inhibitor is essential to prevent the glycol from
accelerating corrosion of metal components in the
system. The glycol and inhibitor levels must be
checked regularly (no less than once annually).
1. At least once annually, sample the system fluid to verify that
the glycol concentrations meets the minimum value given in
Figure 8, page 8. Also test the inhibitor concentration. Add
glycol and inhibitor as needed to return the system to the
correct concentrations.
check operating pressure
1. Check the glycol/water system pressure. Operating pressure
should be between 15 and 25 PSIG. Adjust fluid volume if
needed to restore pressure.
2. If pressure is low, check system for evidence of leaks. Repair
all leaks immediately.
Perform annual inspection
Electrical shock hazard
— Disconnect all electri-
cal power before proceeding with the following.
1. At least once annually, perform a complete inspection of the
system, including at least the following.
❑
Inspect the SCM for signs of dirt or debris accumulation. Re-
move any debris and notify the building owner that the unit
must be kept clean and unobstructed.
❑
Inspect glycol/water system piping and components. Repair
or replace any defective components. Repair all leaks im-
mediately.
❑
Close the isolation valves on either side of the y-strainer at
the SpacePak heat pump/chiller return connection. Remove
the screen and inspect for sediment. Clean if necessary.
• If the strainer has become clogged with sediment, deter-
mine whether the system needs to be drained, cleaned
and re-filled. Excessive sediment accumulation in the
strainer will reduce flow and cause the unit to shut down.
❑
Inspect all wiring and wiring connections. Tighten connec-
tions if needed. Correct any problems found.
❑
Check the fuses or breakers to ensure they are correctly
sized and properly installed.
❑
Clean the SCM heat exchangers and air openings.
❑
Cycle the system on heating and cooling. Verify that all com-
ponents operate correctly.
Preparing the SCM for shut down
DO NOT turn off power to the SCM heat pump/chill-
er in the winter or any time when there is a possibil-
ity of freezing. Power must be ON for the automatic
anti-freeze operation to occur. See information be-
low for preparing the unit for shut down.
1. When the water temperature drops below 34 deg F during
periods of non-use, the pump will start and the antifreeze
heater (optional, when installed) will energize and continue
to operate until the temperature reaches 38 deg F.
2. If SCM must be turned off or left idle during periods when
freezing is possible, one of the following must be done:
a. Verify that sufficient glycol solution is present to protect
against most extreme anticipate conditions
b. — OR — Drain chiller and external piping completely
To restart after shutdown
1. If unit was drained, refill.
2. Follow start up procedure on page 12.
