R e s i d e n t i a l S p l i t - 6 0 H z R 2 2 & R 4 1 0 A
R e v. : 5 J u n e , 2 0 0 8
18
W a t e r- S o u r c e H e a t i n g a n d C o o l i n g S y s t e m s
Refrigeration Installation
Figure 10: Braze Instructions
Fully Insulated
Suction Line
Fully Insulated
Liquid Line
Nitrogen Braze
Service ports for
gauges
CCW
CCW
Rev. 05/31/00
Replace Caps after adjusting
service valves
Braze
connection
Service ports for
attaching refrigerant
gauges
Replace caps
after adjusting
service valves
Table 5: Service Valve Positions
Figure 11: Air Coil Connection
TXV (‘IN’ toward
compressor section)
Suction Line
Liquid Line
Bulb
(Must be
Insulated)
Equalizer
Line
TXV has internal
check valve
Installing the Indoor Coil and Lineset
Figure 11 shows the installation of the lineset and TXV to a
typical indoor coil. An indoor coil or air handler (fan coil) with a
TXV is required. Coils with cap tubes may not be used. If coil
includes removable
fi
xed ori
fi
ce, the ori
fi
ce must be removed
and a TXV must be installed as shown in Figure 11. Fasten
the copper line set to the coil. Nitrogen should be circulated
through the system at 2-3 psi
[13.8-20.7 kPa]
to prevent
oxidation inside the refrigerant tubing. Use a low silver phos-
copper braze alloy on all brazed connections.
Add-On Heat Pump Applications
The indoor coil should be located in the supply side of
the furnace to avoid condensation damage to the furnace
heat exchanger for add-on heat pump applications. A high
temperature limit switch should be installed as shown in Figures
12b and 13b just upstream of the coil to de-energize the
compressor any time the furnace is energized to avoid blowing
hot air directly into the coil, elevating refrigerant pressures
during operation. The heat pump will trip out on high pressure
lockout without some method of disengaging the compressor
during furnace operation. Alternatively, some thermostats with
“dual fuel” mode will automatically de-energize the compressor
when second stage (backup) heat is required.
The TXV should be brazed into place as shown in Figure 11,
keeping the “IN” side toward the compressor section. The
TXV has an internal check valve and must be installed in the
proper direction for operation. Always keep the valve body
cool with a brazing shield and wet rags to prevent damage
to the TXV. Attach the bulb to the suction line using the
supplied hose clamp. Be careful not to overtighten the clamp
and deform the bulb.
NOTICE!
The air coil should be thoroughly washed with a
fi
lming agent, (dishwasher detergent like Cascade) to help
condensate drainage. Apply a 20 to 1 solution of detergent
and water. Spray both sides of coil, repeat and rinse
thoroughly with water.
Evacuation and Charging the Unit
LEAK TESTING -
The refrigeration line set must be pressurized
and checked for leaks before evacuating and charging the unit.
To pressurize the line set, attach refrigerant gauges to the service
ports and add an inert gas (nitrogen or dry carbon dioxide) until
pressure reaches 60-90 psig [413-620 kPa]. Never use oxygen or
acetylene to pressure test. Use a halogen leak tester or a good
quality bubble solution to detect leaks on all connections made
in the
fi
eld. Check the service valve ports and stem for leaks. If
a leak is found, repair it and repeat the above steps. For safety
reasons do not pressurize system above 150 psig [1034 kPa].
System is now ready for evacuation and charging.