13
Step 4 — Connect Piping
CONDENSATE PIPING  — The unit is supplied with a 1-
1
/
4
inch  OD  drain  connection  to  connect  copper  or  PVC  drain
piping. See Fig. 19 below. Maximum pump lift is 27-
1
/
2
 inches.
Fig. 19 —Condensate Drain Connection
Follow  these  recommendations  when  installing  condensate
piping:
• The highest point in the condensate piping should be as
close to the unit as possible. See Fig. 20.
• Condensate  piping  should  slope  downward  in  the
direction of condensate flow with a minimum gradient of
1 inch per 100 inches. See Fig. 21.
Fig. 20 —Condensate Piping
• When  multiple  units  are  connected  to  a  common
condensate drain, ensure that the drain is large enough to
accommodate the volume of condensate from all units. It
is  also  recommended  to  have  an  air  vent  in  the
condensate piping to prevent air lock.
• Condensate piping must not be installed where it may be
exposed to freezing temperatures.
NOTE:  CN18  can  be  disconnected  to  stop  the  pump.  The
condensate switch is CN5, which can be used for gravity drain
protection. See Fig. 22 and 23.
REFRIGERANT PIPING
When connecting refrigerant piping from an indoor unit to an
outdoor unit, follow these guidelines:
• Check  maximum  height  drop  and  length  of  refrigerant
piping between the indoor and outdoor units. To ensure
the  drop  and  length  are  acceptable,  refer  to  the
refrigerant  piping  allowable  limits  in  the  outdoor  unit
installation manual.
• The number of bends in the refrigeration piping must be
less than 15.
• Refrigerant  piping  connection  between  indoor  and
outdoor  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  outdoor  unit  or  MDC  (Multiport  Distribution
Controller) for Heat Recovery systems.
• The refrigerant piping should be dry and free of dust and
other impurities.
• The  bending  angle  of  the  refrigerant  pipe  should  not
exceed 90
° and the bending radius should be as large as
possible to prevent any breakage in piping.
• Use proper cutting and flaring tools to avoid leakage.
• Use a torque wrench for flare nuts. Refer to Table 3 for
flare nut torque recommendations.
Table 3 — Flare Nut Torque Recommendations
• 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.
INSULATION
INDOOR
UNIT
CONDENSATE HOSE CLAMP
LINE STUB
FLEXIBLE DRAIN
CONNECTOR
PVC DRAIN
PIPE
SUSPENSION RODS
STRUCTURAL CEILING
  8 in.
Max 27-1/2 in.
3 ft.
SUPPORT
STRAPS
DRAIN LINE
Fig. 21 — Using a Main Drain to Serve Multiple Indoor Units with Internal Condensate Pumps
Indoor Unit
2~3-15/16 in.
7-7/8 in. 7-7/8 in. 7-7/8 in.
2~3-15/16 in.
2~3-15/16 in.
MAIN DRAIN
(Sloped at 1/50 ~ 1/100)
INDIVIDUAL DRAIN OUTLET FROM EACH INDOOR UNIT
(Must be connected to internal pump and must be routed to
main drain as shown.)
Max 27-1/2 in.
Max 27-1/2 in.
Indoor Unit Indoor Unit
Max 27-1/2 in.
CAUTION
When connecting from an indoor unit to an outdoor unit,
the  isolation  valve  at  the  outdoor  unit  should  be  in  the
closed  position  throughout  the  refrigerant  piping  process.
Failure  to  follow  this procedure  may result in equipment
damage.
OUTSIDE DIAMETER (IN.)
RECOMMENDED TORQUE 
(FT-LB)
1
/
4
15
3
/
8
26
1
/
2
41
5
/
8
48