5
Fig. 4 —Threaded Rod
Step 4 — Connect Piping
CONDENSATE PIPING — The unit is supplied with a
1 inches OD drain connection to connect copper or PVC drain
When installing condensate piping, follow these
recommendations:
• Condensate piping should slope downward in the
direction of condensate flow, with a minimum gradient
of 1 in. per 100 inches.
• Condensate piping must not be installed where it may be
exposed to freezing temperatures.
• Condensate pipe hangers should be spaced 59 in. or less
between hangers.
• For additional recommendations see Fig. 6.
REFRIGERANT PIPING
When connecting refrigerant piping follow these
procedures:
• The refrigerant piping should be dry and free of dust and
other impurities.
• The number of bends in the refrigeration piping must be
fewer than 15.
• The bending angle of the refrigerant pipe should not
exceed 90 degrees and the bending radius should be as
large as possible to prevent any breakage in piping.
• Use a torque wrench for flare nuts. Refer to Table 3 for
flare nut torque recommendations.
Table 3 — Flare Nut Torque Recommendations
• Before connecting any piping to the MDC cut the tips off
every gas and liquid pipe of the MDC unit to release the
gas in the system as shown in Fig. 7, even if the pipe is
not being used for this installation.
PIPING BETWEEN MDC AND INDOOR UNIT —
When connecting indoor units to an MDC follow these
procedures:
• Check maximum height drop and length of refrigerant
piping between the indoor units and MDC. To ensure the
drop and length are acceptable, refer to the refrigerant
piping allowable limits in the manual.
• Refrigerant piping connection between indoor units
should be performed once the units are secured at their
respective installation locations.
• The refrigeration piping starts at the indoor unit and ends
at the MDC.
• Before insulating the suction and liquid refrigeration
pipes, perform pressure and leak tests. For details, see
the outdoor unit installation manual. Insulating both
suction and liquid refrigerant pipes is mandatory.
• Vacuuming and charging of the system should be carried
out as described in the outdoor unit installation manual.
CAUTION
Multiport Distribution Controller’s (MDCs) are shipped
from the factory with brazed caps on all lines and
pressurized with nitrogen to keep the system clean.
Cutting the tip relieves the pressure in the system. Cut
all the tips on the MDC piping prior to removing any
brazed caps. Failure to cut the tip before removing the
brazed cap may cause equipment damage or personal
injury.
a40-1722
Fig. 5 — Connecting the Condensate Drain
(1[
ĭ
25])
Hard PVC binder
Condensate outlet
pipe
Drain pan
Clamp
Condensate connection
PVC water
Fig. 6 — Space Required for Condensate Drain
Installation
Pipe hanger
59” or less
Refrigerant pipe
(Gradient: 1 in. per 100 in.)
Minimum 2”
Ceiling
7 7/8” or more
59” or less
Outside Diameter (in.)
Recommended Torque (ft-lb)
1/4
15
3/8
26
1/2
41
5/8
48
CAUTION
MDCs are shipped from the factory with brazed caps on
all lines and pressurized with nitrogen to keep the
system clean. Failure to remove the brazed cap before
connecting piping will result in equipment malfunction
or damage.
Fig. 7 — Cutting the Tip off the Gas and Liquid
Lines
c
a
b
LEGEND
a
—
Brazed Cap
b —
Cut Here
c
—
MDC Unit
