Daikin Enfinity CCH - Maintenance and Troubleshooting; R-410 A Refrigerant Handling Guidelines

MaintenanCe
IM 1049-9 36 www.DaikinApplied.com
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fty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-ammable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- 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ash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 opera-
tion 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 10° to 14°
Note: All information above is based on ISO standard
13256-1 and tested at these conditions.
General Maintenance
1. Normal maintenance on all units is generally
limitedtolter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. Some applications such
as motels produce a lot of lint from carpeting and
linenchanges,andwillrequiremorefrequentlter
changes.Checkltersat60-dayintervalsforthe
rstyearuntilexperienceisacquired.Iflightcannot
beseenthroughthelter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ushed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owrates,water
temperatures,airowrates(maybeadirtylter),
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.