Step 3 - Make Piping Connections; Cooling And Heating Connections; Horizontal Ceiling Drain Pan Removal; (42C Units) - Carrier 42C Series Installation Instructions Manual

Step 3 — Make Piping Connections
Access to piping is available through the access panels at the side
of the units or front of the unit. Qualified personnel in accordance
with local and national codes must perform all piping connections.
Refer to Tables 1-3 for piping connections.
NOTE: It is important to have a common understanding of which
side of the unit is the right-hand side and which is the left-hand
side.
When facing the supply-air outlet from the front of the unit (air
blowing in your face), your right hand will be on the right side of
the unit and your left hand will be on the left side of the unit. See
Fig. 75. Refer to Fig. 76 and 77 for typical piping connections.
Refer to Appendix D on page 91 for Valve and Piping connection
packages.
The supply and return piping connections of the factory-provided
valve package are either swaged for field brazing (standard) or
union-fitted (optional) for field connection to the coil.

Cooling and Heating Connections

HORIZONTAL CEILING DRAIN PAN REMOVAL 

(42C UNITS)

After mounting the unit, it is then ready for the various service
connections such as water, drain and electrical. At this time, it
should be verified that the proper types of services are actually
provided to the unit. On those units requiring chilled water and/or
hot water, the proper line size and water temperature should be
available to the unit. In the case of refrigerant cooling, the proper
line size and refrigerant type should be available to the unit. On
units with steam-heating coils, the proper line sizing and routing
should be verified, and the maximum steam pressure applied to
the unit should never exceed 10 psig (69 KPa). The drain piping
and steam trap should be sized and routed to allow for proper con-
densate flow.
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.
NOTE: Submittals and product literature detailing unit operation,
controls, and connections should be thoroughly reviewed
BEFORE beginning the connection of the various cooling and/or
heating mediums to the unit.
42CA, CE, CK and CG Horizontal models come with a remov-
able drain pan. The drain pan should be removed before installing
or servicing the valve package. An extended drill bit may be nec-
essary to access the screws to remove the drain pan.
NOTE: Exact location of screws to remove drain pan may vary
based on horizontal model.

CONDENSATE DRAIN PAN (ALL UNITS)

The drain should always be connected and piped to an acceptable
disposal point. For proper moisture carry-off, the drain piping
should be sloped away from the unit at least 1/8 inch per foot. A
drain trap may be required by local codes and it is strongly recom-
mended for odor containment. When furnished, the optional
5/8 in. secondary or "tell-tale" connection must be piped to some
location where an indication of drain flow restriction may be read-
ily observed. Units furnished with a "tell-tale" connection should
be sloped very slightly towards the drain outlets. The differential
height of the trap inlet to outlet must be at least one inch greater
than the total static pressure on the unit. The height from the drain
outlet to the bottom of the trap must not be less than the total static
pressure. The condensate drain hose should be secured with a
clamp after installing.
Fig. 75 — Unit End Reference

VALVE PACKAGES

There are limitations on physical size of control valves, quantity
and type of matching components, and required control interface.
See figure "Symbols and Placement of Valves" on page 93 for
valve placement.
Consult factory before ordering any special valve package compo-
nents that are not covered in this book.
Valve packages are shipped with the units or in unit cartons. Valve
packages include belled ends for field soldering to coil
connections.
All factory-furnished cooling valve packages are arranged to posi-
tion as much of the package as possible over an auxiliary drain pan
or drip lip. This helps minimize field piping insulation require-
ments. Refer Appendix D "Piping and VALVE CONNECTIONS"
on page 91 for pipe connection configurations.

AUXILIARY DRAIN PAN

On some units (42V*D, 42V*A), an auxiliary drain pan is
included to collect condensate from the primary drain pan and
then to direct this condensate to a drain by way of a sloped pipe,
recommended to include a p-trap or other air-trap device. The
auxiliary drain pan is also to collect any condensate coming from
a valve package or other piping connected to the coil. Included
with each unit is a feature for connecting the auxiliary drain pan,
found on the lower section of the inner-case leg, a part of the
metal casing supporting the coil and fan, and to the same side as
where piping connects to the coil and where any valve package is
located.
The auxiliary drain pan is shipped loose from the factory and must
be installed directly below the drain tube leading from the primary
drain pan and a condensate overflow switch where applicable.
The auxiliary drain pan is situated to the inner-case leg by way of
either supporting tabs extending from the case leg or by way of
slots in the case leg. The drain pipe or a drain trap is then
connected to the stub-out off the bottom side of this pan. Finally,
confirm that the pan is secure and positively situated so that con-
densate coming from the primary drain pan is collected. See
Fig. 77.
CONDENSATE
PAN STUB-OUT
7/8 IN. FIELD-SUPPLIED
DRAIN EXTENSION
Fig. 76 — Typical Drain Line Details
(42D Unit Shown)
69
2 IN. MIN
TRAP