20
Fig. 20 — Locate 42SUA Unit Knockouts
Fig. 21 — Remove 42SUA Unit Knockouts
Fig. 22 — 42SUA Unit Knockout Insulation Removal
NOTE: Submittals and product literature detailing unit operation,
controls, and connections should be thoroughly reviewed
BEFORE beginning the connection and testing of risers and
piping.
To assure optimal unit performance, the supply connection(s) are
marked on the unit’s coil with an “S” meaning supply or inlet and
“R” meaning return or outlet indicating flow direction to and from
the coil. Blue letters mark the chilled water connections and red
letters mark the hot water connections.
The unit’s internal piping is designed to accommodate a total riser
vertical movement of ±1-1/2 in., due to thermal expansion and/or
contraction, when positioned properly at the jobsite. Risers must
be anchored to the building structure to limit expansion and con
-
traction movement to a maximum of 3 inches. Riser anchoring
and expansion compensation is not included in the unit and must
be provided. Riser end caps, air vents, and/or flushing loops must
be provided at the jobsite by the installer.
Proper field riser installation and vertical positioning in the unit
should have a pipe run-out to the service valves which are cen
-
tered in the knockout access slots and that slope down slightly
away from the riser (see Fig. 23). This prevents condensation from
running back to the riser and possible damage from dripping at the
bottom of a riser column. Each job has specific requirements and
satisfying those requirements is the responsibility of the installer.
Riser to Unit Installation
Before making the riser joints, the riser insulation must be pulled
back away from the joint and protected from heat during the braz
-
ing process. Each riser joint must be in vertical alignment. Varia
-
tions in floor-to-floor dimensions may require field work such as
cutting off or extending the risers. This operation is the responsi
-
bility of the installer. The riser joint filler material must be selected
to withstand the total operating pressure (both static and pumping
head) to which the system will be subjected. Low temperature
lead alloy solders such as “50/50” and “60/40” are normally not
suitable.
Riser to Drain Installation
1. After the applicable supply, return, and drain knockouts have
been removed, carefully position the unit so that the riser ball
valves penetrate into the unit through the riser knockouts,
making sure the insulation penetrates into the unit as shown
in Fig. 23-26.
Top Supply
Air Knockout
TOP VIEW
Electrical
Knockouts
Side Supply Air
Knockout
(1 per side)
Riser Knockouts
(4 per side,
except on
Return Air side)
Drain Knockout
(1 per side,
except on
Return Air side)
Outside Air
Knockout
(2 sides only,
adjacent to
Return Air
opening)
SIDE VIEW
Return
Air
Optional
Electrical
Knockouts
Knockout
Slot
Knockout
Tab
KNOCKOUTS:
Knockout
Knockout
Tab
Drain
Knockout
Supply and Return
CAUTION
Toxic residues and loose particles resulting from manufactur
-
ing and field piping techniques such as joint compounds, sol
-
dering flux, and metal shavings may be present in the unit and
the piping system. Special consideration must be given to sys
-
tem cleanliness when connecting to solar, domestic or potable
water systems. Coil not rated for potable use.
Drain
Insulation
Cut Line
Supply and Return
Insulation Cutline