15
• The vapor line must be insulated to prevent dripping (sweating) and prevent
performance losses. Armaflex and Rubatex are satisfactory insulations for this
purpose. Use 1/2” minimum insulation thickness, additional insulation may be
required for long runs.
• Check Table 3 for the correct vapor line size. Check Table 4 for the correct liq-
uid line size.
7.5 Tubing Connections
Indoor coils have only a holding charge of dry nitrogen. Keep all tube ends sealed
until connections are to be made.
• Use type “L” copper refrigeration tubing. Braze the connections with the follow-
ing alloys:
–
copper to copper - 5%
– Silver alloy (no flux)
– copper to steel or brass - 35%
– silver alloy (with flux)
• Be certain both refrigerant shutoff valves at the outdoor unit are closed.
• Clean the inside of the fittings and outside of the tubing with steel wool or sand
cloth before soldering. Always keep chips, steel wool, dirt, etc., out of the inside
when cleaning.
• Assemble tubing part way into fitting. Apply flux all around the outside of the
tubing and push tubing into stop. This procedure will keep the flux from getting
inside the system.
• Remove the cap and schrader core from service port to protect seals from heat
damage.
• Use an appropriate heatsink material around the copper stub and the service
valves before applying heat.
• IMPORTANT: Do not braze any fitting with the TEV sensing bulb attached.
• Braze the tubing between the outdoor unit and indoor coil. Flow dry nitrogen
into a service port and through the tubing while brazing.
• After brazing – use an appropriate heatsink material to cool the joint and
remove any flux residue.
• The service valves are not backseating valves. To open the valves, remove the
valve cap with an adjustable wrench. Insert a 3/16” or 5/16” hex wrench into the
stem. Back out counterclockwise.
• Replace the valve cap finger tight then tighten an additional 1/2 hex flat for a
metal-to-metal seal.
7.6 Leak Testing
• Pressurize line set and coil through service fittings with dry nitrogen to 150
PSIG maximum. Leak test all joints using liquid detergent. If a leak is found,
recover pressure and repair.
8.0 COMPRESSOR CRANKCASE HEAT (CCH)
CCH is standard on these models due to refrigerant migration during the off cycle
that can result in a noisy start up.
Crankcase Heater Operation:
Supplemental Crankcase heat is required to prevent refrigerant migration in sys-
tems with relatively high system refrigerant charges.
The crankcase heater control is integrated into the Comfort Control
2
and is
designed for maximum energy savings.
Summary of operation:
• The crankcase heater is off whenever the compressor is running.
!
WARNING
DO NOT USE OXYGEN TO PURGE LINES OR PRESSURIZE SYSTEM FOR
LEAK TEST. OXYGEN REACTS VIOLENTLY WITH OIL, WHICH CAN
CAUSE AN EXPLOSION RESULTING IN SEVERE PERSONAL INJURY OR
DEATH.
To Next Page
Loading...
