23
Riser to Unit Installation
Proper riser installation and vertical positioning in the unit pro
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vides for a unit piping run-out to the service valves which are cen
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tered in the access slots and level or sloping down slightly away
from the riser. This prevents condensation from running back to
the riser and possible damage from dripping at the bottom of a ris
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er column. Each job has specific requirements and satisfying those
requirements is the responsibility of the installer.
Riser to Drain Installation
1. Carefully position the unit so that the riser ball valves pene
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trate into the unit through the riser slot making sure the insu
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lation penetrates into the unit as shown in Fig. 30 and 31.
Fig. 30 — 42SMA Riser to Unit Installation
Fig. 31 — 42SMA Riser to Unit Connection
2. Before anchoring the equipment in place, the unit must be
leveled and the cabinet must be plumb and squared. The
unit may be anchored in place by bolting directly through
the unit’s floor or attaching to the building walls through the
cabinet walls in some location that will not interfere with
drywall or other items such as the supply grille, thermostat,
or return access panel. When attaching sheet rock to the unit
cabinet, care must be taken to not penetrate the cabinet in
locations that may damage internal components or wiring.
The mounting technique is a matter of choice; however, the
unit should always be anchored securely to the building to
prevent movement during construction and riser expansion
and contraction. After anchoring the unit, it is then ready for
the various service connections such as riser connections
and electrical.
3. The plastic flare caps on the end of the riser ball valves
should be removed and discarded.
4. All mega stack units use reinforced braided stainless steel
flexible hose kits for piping between field-installed risers and
unit water coils as shown in Fig. 31. Each hose has threaded
connections on each end. The hose kits allow for riser fluctu
-
ations due to thermal expansion.
5. Use a wrench to tighten the swivel connections. Use a backup
wrench to hold the riser ball valve stationary to prevent it
from bending or twisting during installation as shown in
Fig. 32. Be careful not to over-tighten swivel connections.
Fig. 32 — 42SMA Riser to Unit Installation
(Tighten Swivel Connections)
6. Locate the unit’s coil fitting.
7. The plastic flare caps on the end of the coil fitting should be
removed and discarded.
8. Use a wrench to tighten the swivel connections. The baffle
acts as a secondary wrench. Be careful not to over-tighten
swivel connections.
9. Locate the p-trap drain and rubber hose factory installed to
the drain pan connection in the bottom of the unit as shown in
Fig. 33.
10. Push the rubber drain hose over the riser drain stubout. Be
careful that you do not bend the drain stubout.
11. Adjust the hose clamp over the riser stubout and rubber hose
to hold in place as shown in Fig. 33.
Fig. 33 — 42SMA Riser to Drain Installation
Outer
Cabinet
Unit Insulation
Rise Stubout
Insulation
Ball
Valve
Threaded
Fitting
Flare
Cap
Riser Knockout
Slot
Flexible
Hose Kit
Riser Stubout
Insulation
Ball Valve
Riser
Coil
Baffle
Connection point to any factory
furnished and installed components.
CAUTION
Hose connection torque requirements are 350 in. lb +10/
–0 in. lb to prevent leaks.
Wrench
Swivel
Connection
Back-up
Wrench
Ball Valve
P-Trap
Drain
Clamp
Drain Pan
Unit Insulation
Riser Knockout
Clamp
Riser
Stubout
Unit Wall
Riser