McQuay MHC Series, Installation & Maintenance Data, Page: 8 / 36

Page 8 of 36 / IM 985-1
8 .­ Units­are­internally­trapped .­Copper­or­PVC­
condensate­lines­can­be­used .­A­means­of­
disconnection­must­be­furnished­to­facilitate­chassis­
removal .
9 .­ No­point­of­the­drain­system­may­be­above­the­drain
­
pan­of­any­unit .
10. Automatic flow control devices must not be installed
prior to system cleaning and flushing.
11 .­A­high­point­of­the­piping­system­must­be­vented .
12 .­Check­local­code­for­any­requirement­for­electric­
fittings.
Water Connections
All­piping­connections­should­be­made­using­good­
plumbing­practices­and­in­accordance­with­any­and­all­
local­codes­that­may­apply .
Note:
­
On left-hand piping units the water supply
connection is on the top. Right hand piping units the
water supply is at the bottom location.
Unit Piping Connection
Each­heat­pump­is­supplied­with­extended­copper­
tubing on the water-to-refrigerant coil and 5/8" (16mm)
O .D .­tubing .­The­connections­are­for­both­the­supply­
and­return­water­connections .­See­Figure­5­for­left­and­
right­hand­connections­locatons .
Shutoff/Balancing Valve Piping
Each­heat­pump­requires­a­shutoff­valve­on­both­the­
supply­and­return­lines­for­easy­serviceability­and­
removal­if­it­becomes­necessary .
We­suggest­using­our­combination­shutoff/balancing
valves installed in the field between the contractor’s
piping­and­the­heat­pump­unit .­The­valve­installed­on­
the­return­line­acts­as­a­balancing­valve­to­adjust­the­
proper water flow. An automatic flow limiting device is
also­available­as­a­factory­installed­option .
Each shutoff/balancing valve has 1/2" FPT and 1/2"
FPT­threaded­connections .
Attach the field installed combination shut/off balancing
valve­to­the­building­water­supply­and­return­piping .­
Add­the­female­pipe­adapter­connection­to­unit­supply­
and­return­coil­connection­by­sweating­them­in­place­
using­silver­solder .
Using the specified hoses, screw the fixed end
into the shut-off/balancing valve. Remove the 1/2"
adapter­from­the­other­end­of­the­hose .­Insert­the­
adapter into the female fitting. Using two crescent
wrenches,­one­to­hold­the­pipe­connection­and­the­
second­to­tighten­the­adapter,­insert­the­swivel­end­of­
the­hose­on­the­adapter­and­tighten .­This­completes­the­
hose­connection­to­standard­heat­pump­equipment .
Figure 5. Supply and Return Connections Locations for Left- Hand and Right Hand Units (Flat Top and Slope Top)
Right-Hand Piping View
Left-Hand Piping View
On left-hand piping units the
water supply connection is on
the top. Right-hand piping units
the water supply is at the bottom
location.
IMPORTANT
Unit Size J K L M P Q R S
007-018
6⅞
" 5 1 / 5 " 6¾" 3½" 10¼" 1 3 / 5 " 5¼" 7½"
(175mm) (132mm) (172mm) (90mm) (260mm) (41mm) (134mm) (192mm)
Dimensions (High Sill Units)