Daikin RCS Series Installation And Maintenance Manual page 17

Quick Reference Guide for R410A
• R410A refrigerant operates at approximately 60% higher
pressure (1.6 times) than R22. Ensure that servicing
equipment is designed to operate with R410A.
• R410A refrigerant cycles are pink in color.
• R410A, as with other HFC's is only compatible with POE
oils.
• Vacuum pumps will not remove moisture from oil.
• R410A systems are to be charged with liquid refrigerants.
Prior to March 1999, R410A refrigerant cylinders had
a dip tube. These cylinders should be kept upright for
equipment charging. Post March 1999 cylinders do not
have a dip tube and should be inverted to ensure liquid
charging of the equipment.
• Do not install a suction line filter drier in the liquid line.
• A liquid line filter drier is standard on every unit. Only
manufacturer approved liquid line filter driers can be
used. These filter driers are rated for minimum working
pressure of 600 psig.
• Desiccant (drying agent) must be compatible for POE oils
and R410A.
Replacement Units
To prevent failure of a new condensing unit, the existing
evaporator tubing system must be correctly sized and cleaned
or replaced. Care must be exercised that the expansion device
is not plugged. For new and replacement units, a liquid line
filter drier should be installed and refrigerant tubing should be
properly sized. Test the oil for acid. If positive, a suction line
filter drier is mandatory.
Important: When replacing an R22 unit with an R410A unit,
either replace the line set or ensure that the existing line set is
thoroughly cleaned of any old oil or debris.
Evaporator Coil
Refer to evaporator coil manufacturer's installation instructions.
Important: The manufacturer is not responsible for the
performance and operation of a mismatched system, or for a
match listed with another manufacturer's coil.
CAUTION
Only use evaporators approved for use on R410A systems. Use of existing
R22 evaporators can introduce mineral oil to the R410A refrigerant forming
two different liquids and decreasing oil return to the compressor. This can
result in compressor failure.
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Evacuation and Charging
The evacuation of any system component that has been
exposed to atmosphere or lost its charge is essential before
charging. Never attempt to operate a system while it is under a
vacuum.
NOTE: The condensing unit is shipped with a holding charge
of dry nitrogen which must be purged from the unit
before evacuation.
1 . Since the condensing unit itself must be evacuated, open
the vapor, discharge and liquid shut-off valves.
2 . Use a refrigeration type vacuum pump capable of
evacuation in the 500 micron range.
3 . Connect the vacuum pump to the service manifold
assembly with a pressure gauge that will read 30 inches
vacuum. Connect the service manifold to the vapor line
service port. ("Low" shown on label.)
4 . With an accurate scale, 1/2 oz., set refrigerant tank up so
its weight can be measured while in a position to charge
liquid. (Unit must be OFF.) Energize liquid line solenoid
valve by wiring valve to 24V power supply (or open by
manual stem if applicable).
5 . Connect to the liquid line service port. ("High" shown
on label.) Shut off tank and evacuate the system. The
pressure gauge should read at least 29.5" of vacuum.
6 . Triple evacuate the system.
7 . The refrigerant system will now be free of
noncondensables.
8 . Remove vacuum pump from 3-way valve.
9 . Install refrigerant tank (liquid charging) to liquid line
service valve.
10 . Before tightening, purge tank and service valve hose.
11 . Note weight of refrigerant tank.
12 . De-energize liquid line solenoid valve. Open refrigerant
tank valve. Allow pressure in tank and unit to equalize.
13 . Close off service valve to liquid line service port and note
weight of refrigerant tank.
14 . Position tank for gas charging.
15 . Rewire liquid line solenoid to thermostat control.
Close main disconnect switch and turn thermostat to
lowest setting.
16 . Charge unit per
17 IM 962-4 • AIR-COOLED SPLIT SYSTEM CONDENSERS
Installation
Table 12 and Table 13 .