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The in and outs of R-410A
R-410A is a non-ozone depleting blend of two
refrigerants - HFC-125 and HFC-32 in a fifty percent
mixture. R-410A exhibits higher operating pressure and
refrigeration capacity than R-22. R-410A is intended
for use in new air conditioning applications that have
traditionally been used HCFC-22 (R-22). Due to higher
capacity and pressure of R-410A, it must not be used in
existing R-22 systems.
Although R-410A is non-flammable at ambient
temperature and atmospheric pressure, it can become
combustible under pressure when mixed with air.
Note: R-410A should not be mixed with air under pres-
sure for leak testing. Pressure mixtures of dry
nitrogen and R-410A can be used for leak testing.
Lubrication
R-410A should be used only with polyester (POE)
oil. The HFC refrigerant components in R-410A will
not be compatible with mineral oil or alkylbenzene
lubricants. R-410A systems will be charged with the
OEM recommended lubricant, ready for use with R-410A.
Charging
Due to the zeotropic nature of R- 4 10A, it should be
charged as a liquid. In situations where vapor is normally
charged into a system, a valve should be installed in the
charging line to flash the liquid to vapor while charging.
M ake certain that the recycle or recovery equipment
used is designed for R-410A. The pressure of R-410A
refrigerant is approximately 60 percent greater than
that of R-22. Pressure gauges require a range up to
800 PSIG high side and 250 PSIG low side. Recovery
cylinders require a 400 PSIG rating – do not put R-410A
in a 300 PSIG rated cylinder.
Note: Because a water source heat pump operates
under a wide range of water and air tempera-
tures, the values printed below are to be taken
as suggested pressure and temperatures.) All
Daikin water source heat pumps are designed for
commercial use. The units are designed for the
cooling mode of operation and fail safe to cooling.
The reversing valve is energized for the heating
mode of operation.
Superheat
Head Pressure
8 to 14 degrees
335-355 PSIG
All information above is based on ISO standard 13256-1
and tested at these conditions.
www .DaikinApplied .com
General Maintenance
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Water Delta T
10° to 14°
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Normal maintenance on all units is generally
limited to filter changes. Units are provided with
permanently lubricated motors and require no oiling
even though oil caps may be provided.
Filter changes are required at regular intervals. The
time period between changes will depend upon
the project requirements. Some applications such
as motels produce a lot of lint from carpeting and
linen changes, and will require more frequent filter
changes. Check filters at 60-day intervals for the
first year until experience is acquired. If light cannot
be seen through the filter when held up to sunlight
or a bright light, it should be changed. A more critical
standard may be desirable.
The condensate drain pan should be checked
annually and cleaned and flushed as required.
Record performance measurements of volts, amps,
and water temperature differences (both heating
and cooling). A comparison of logged data with start-
up and other annual data is useful as an indicator of
general equipment condition.
Periodic lockouts almost always are caused by
air or water problems. The lockout (shutdown) of
the unit is a normal protective result. Check for
dirt in the water system, water flow rates, water
temperatures, airflow rates (may be a dirty filter),
and air temperatures. If the lockout occurs in the
morning following a return from night setback,
entering air below machine limits may be the cause.
Enfinity Vertical Water Source Heat Pumps • IM 930-6
t
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