The In And Outs Of R-410A; Lubrication; Charging; General Maintenance - Daikin VHF Installation And Maintenance Manual

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 pressure
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- 410A, 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.
Make 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.
WARNING
Recycle/recovery equipment must be designated for
R-410A. R-410A pressure is greater than R-22. Improper
equipment can cause severe injury or death.
Note: Because a water source heat pump operates under a
wide range of water and air temperatures, 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 Water Delta T
8 to 14 degrees 335-355 PSIG
Note: All information above is based on ISO standard 13256-
1 and tested at these conditions.
IM 986-11 • Vertical Stack WSHP

General Maintenance

• 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.
Note: Because a water source heat pump operates under a
8 to 14 degrees
Note: All information above is based on ISO standard 13256-
10° to 14°
55
wide range of water and air temperatures, 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
335-355 PSIG
1 and tested at these conditions.
g M
eneral aintenanCe
Water Delta T
10° to 14°
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