System information
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Refrigerant Piping Procedures: Cleanliness is of the utmost importance. All horizontal suc-
tion piping shall be pitched toward the condensing unit 1/2” for every 10’ of pipe. During any
brazing procedure, dry Nitrogen shall be purged through the tting at a slow rate to prevent
formation of highly abrasive Copper Oxide. Make sure there are no obstructions to the ow
which would cause pressure build up and the brazed tting to leak. After leak testing and con-
rming there are no refrigerant leaks, insulate suction line with 1/2” wall thickness Armaex or
equal type insulation. All seams have been sealed with Armaex 520 Foam Insulation Adhesive
or equivalent and have been wrapped with line set tape to prevent the intrusion of humidity.
Evacuate the system with a vacuum pump to 200 microns or less measured with a digital mi-
cron gauge connected to the Schrader Type Access valve in the suction line.
Procedures followed:
Prior to connecting the piping, loosely connect refrigerant gauges to the service ports of the
suction and liquid line service valves. Purge the charging hoses with dry Nitrogen, tighten
hose connections, remove service valve caps, followed by turning service valve stem 1/2 turn
clockwise to unseat the valve from its back seated position and opening the service port to the
gauges. Keep the piping port sealed until ready to connect to the tubing.
Procedures followed:
It is required to use a 1/4” OD Copper tube liquid line. When making connections, keep the
ends sealed until ready to t the tube. First, connect the supplied refrigerant drier close to the
liquid service valve (king valve) on the receiver. Downstream, connect the moisture indicating
sight glass in an easily visible location. Run the tubing to the evaporator location and t to the
liquid line stub from the evaporator unit. Energize the evaporator unit and set the temperature
controller to activate the liquid line solenoid valve. Uncap the suction pipe to prevent obstruct-
ing Nitrogen ow. Open the Nitrogen to allow a slow ow and braze the liquid line tting. Shut
o the Nitrogen and power until suction line is brazed.
Procedures followed:
Suction line tubing size selection is dependent on the capacity of the unit being installed,
length of the suction line, and the length of vertical lift if any. Determine if the condensing unit
is above the elevation of the fan coil unit and if so, the distance above in feet. In some cases,
one size smaller tubing is required for the vertical length only. For the Mini split, with about
1650 BTUH nominal capacity, 3/8”OD tubing is required for up to 100’ equivalent length and is
OK for a vertical rise. For the 4000 series with about 4700 BTUH nominal capacity, 1/2” OD tub-
ing is required for up to 50’ equivalent length. 5/8” OD is required for line set lengths between
51’ and 100’. 1/2” OD is required for a vertical rise of 10’ or more. For the 7000 and 8000 series
with about 6000 BTUH nominal capacity, 1/2” OD tubing is required for up 25’ equivalent length.
For line set lengths 26’ to 100’, 5/8” OD tubing is required. 1/2” OD is required for a vertical rise
more than 3’. In accordance with the piping diagrams (found in the Split Owners Manual), an in-
verted loop or trap is advised above the riser to prevent oil running back down the tube during
the o cycle. Please ll the unit size, equivalent length and size of tubing installed.
Unit __________________ Length ______________ Tube size ___________
Vertical rise ____________ Tube size ____________