Comfort-Aire HTS Series Split System,Two Stage, 2-5 Tons - Manual (Page 16)

Figure 10: Braze Instructions Figure 11: Air Coil Connection
Table 6: Service Valve Positions
Fully Insulated
Suction Line
Fully Insulated
Liquid Line
Nitrogen Braze
Vapor
Service ports for
gauges
CCW
CCW
Rev. 05/31/00
Replace Caps after adjusting
service valves
16
Installation, Operation & Maintenance HTS SERIES SPLIT SYSTEM Heat Controller, LLC
Refrigeration Installation
Position Description System
Service
Port
CCW - Full Out Operation Position Open Closed
CCW -Full Out 1/2
turn CW
Service Position Open Open
CW - Full in Shipping Position Closed Open
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 orifi ce, the orifi 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 HWG Series 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.
TXV (‘IN’ toward
compressor section)
Suction Line
Liquid Line
Bulb (Must be
Installed and
Insulated)
Equalizer
Line
TXV has internal
check valve
FP2
Sensor