Carrier 42S Series - Page 21

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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 baf-
fle 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. 30.
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. 30.
Fig. 30 — 42SM Riser to Drain Installation
12. Test for leaks. Any and all leaks should be repaired
before proceeding with installation. When testing with
air or some other gas, it might be necessary to tighten
stem packing nuts on some valves to maintain air pres-
sure in the riser. Pressure testing risers with water should
be done with the unit service valves closed to prevent
flushing debris into the unit valve packages. These
valves will also allow risers to be drained down after
testing in the winter to avoid freeze-up problems. In the
event that leaking or defective components are discov-
ered, the sales representative must be notified BEFORE
any repairs are attempted. All leaks should be repaired
before proceeding with the unit installation.
13. After system integrity has been established, the riser
insulation must be pulled back into place over the joint
and glued or sealed to prevent sweating and heat loss or
gain. All of the risers including the riser stubouts should
be properly covered with insulation. Internally mounted
chilled water piping and valves are located over the drain
pan and need not be insulated.
Any fireproofing requirements where risers or piping
penetrate floors or walls are the responsibility of the
installer. This work should be done only after all pressure
testing is completed. The fireproofing method used must
accommodate pipe expansion and contraction and the
piping must be protected from abrasion and chemical
attack. The pipe insulation also must be maintained to
prevent sweating and must be protected from wear or
erosion at the joint between the insulation and the fire-
proofing material.
When no risers are ordered for the mega stack unit, it is
the responsibility of the installer to make sure that a
field-supplied isolation ball valve is installed between
each supply and return piping connection to the unit.
Flare fittings are factory provided to allow connection
between the ball valves and the hoses.
Variations in floor-to-floor dimensions may require field
work such as cutting off or extending the risers. This
operation is the responsibility 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 nor-
mally not suitable.
Chilled water and hot water risers should never be piped
to drain down into the condensate riser. Extensive water
damage can occur due to drain overflow. Drain chilled
and hot water risers to a remote location away from the
unit such as sink, room, or floor drains.
All installations should be made in compliance with all
governing codes and ordinances. Compliance with all
codes is the responsibility of the installing contractor.
Supply Air Installation
1. If the unit has been ordered with a supply air plenum,
then each side of the unit has one supply air knockout as
well as a supply air knockout on the top of the unit (see
Fig. 31 and 32).
2. Determine which supply air opening/openings are
required for your application.
NOTE: The supply air opening on the riser side of the unit
should not be used.
3. Use a sharp retractable knife to trim insulation using cen-
ter knockout slot/trim line as pattern (see Fig. 33).
4. Use a sharp standard needle nose pliers and grab knock-
out tab (see Fig. 33).
5. Twist or pry pliers back and forth until knockout tab
breaks away from unit.
6. Repeat for all supply air tabs until all have been broken.
7. Discard center knockout piece. Be careful of sharp
edges.
8. Use a sharp retractable knife to trim any excess insula-
tion using knockout hole as pattern.
9. Use duct pliers (hand seamers) to fold duct flange out of
the unit 90 degrees for each side of the supply air open-
ing along duct break (see Fig. 33). The 90-degree flanges
can now be used as drywall stops to prevent coverage of
discharge opening (see Fig. 34).
Fig. 31 — 42SM Unit Knockout Locations
Side View (Typical)
CAUTION
Hose connection torque requirements are 350 in. lb +10/
–0 in. lb to prevent leaks.
DRAIN PAN
DRAIN
CLAMP
CLAMP
RISER KNOCKOUT
UNIT INSULATION
PTRAP
UNIT WALL
RISER
RISER STUBOUT
SIDE SUPPLY AIR
KNOCKOUT
1 PER SIDE
SIDE VIEW
MEGA MOD
CABINET
OPTIONAL
SUPPLY
PLENUM