Troubleshooting; The In And Outs Of R-410A; Lubrication; Charging - Daikin ARQ Installation Manual

Troubleshooting

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
.
Note: 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
.
All information above is based on ISO standard
13256-1 and tested at these conditions.
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.
IM 1083
WARNING
Self-Contained WSHP Unit Ventilator Models ARQ, ERQ, GRQ

General Maintenance

1. 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.
2. Filter changes are required at regular intervals. The time period
between changes will depend upon the project requirements.
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.
3. The condensate drain pan should be checked annually and cleaned
and flushed as required.
4. 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.
5. 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.
6. Oil fan shaft bearing periodically.
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