Location; Cap Plugs; Evaporators - Carrier Transport Air Conditioning Installation Procedures Manual

2.1 INTRODUCTION
2.1.1 Description
Evaporators are located in the interior of the bus. Their
primary function is to transfer heat contained in the
passenger compartment into the refrigerant. The
evaporators may be free blow mounted in the front, side
or rear of the bus to blow directly into the interior or
ducted to distribute the air in a planned pattern.

2.1.2 Location

Before attempting to install any evaporator, always
insure that the evaporator will fit in the location of choice.

2.1.3 Cap Plugs

Carrier Transport Air Conditioning evaporators are
leak-checked at the factory then shipped with a small
charge of inert gas which keeps the coil free from
moisture. The evaporator caps/plugs must not be
removed until ready to use.
2.1.4 Blower Wheels
Before installing any GEN 4 evaporator assembly, spin
the blower wheels by hand to insure they turn freely. It is
possible they could have been knocked out of alignment
during transit. This would be easier to correct before
installing.
CAUTION
When installing a GEN-5 evaporator assem-
bly, never push against the blower wheel. It
can easily be knocked out of balance. Hold
unit up to the ceiling with the evaporator
framing, not the blower wheel.
NOTE
When a GEN-5 blower wheel is damaged dur-
ing installation, it must be replaced, it cannot be
repaired.
2.1.5 Aesthetics
When the installation is completed, the evaporator
fittings and trim should be visually examined for
completeness and looks. All trim should be flush and
mounting hardware hidden from sight where possible in
a manner designed to be pleasing to the customer.
2.1.6 Mounting (Front & Rear)
Carrier Transport Air Conditioning recommends
sufficient structure be built into the bus ceiling by the
"OEM" (original equipment manufacturer) so that the
bus roof will not have to be drilled through when
mounting the evaporator assemblies. When and if the
bus roof is drilled through to mount the evaporator, care
SECTION 2

EVAPORATORS

must be taken to ensure that the bus roof is properly
sealed to prevent leaks.
2.1.7 Mounting (Side)
Mounting brackets (front & rear) must always be
attached to the bus roof bows. Installing the mounting
brackets to the bus ceiling skin will not provide sufficient
support for the evaporator.
2.1.8 In-Wall Evaporators
In-Wall Evaporators are installed in the rear and/or front
of a bus. The interior bus wall in the designated area
must be removed in order to accomodate and install
these type evaporators. Some of Carrier Transport A/C
In-Wall evaporators assemblies are "OEM" specific.
2.1.9 Drain Lines
The drain lines must always run down hill immediately
from the attachment point on the evaporator drain pans.
Both drains should be run independently and in opposite
directions for maximum efficiency. Drain line routing
must be smooth and without kinks. Failure to properly
route the drain lines may result in water back-up into the
passenger compartment.
2.1.10 Ducted Systems
In ducted systems, insure that all refrigerant hoses and
electrical harnesses are firmly attached to the ceiling.
Failure to secure these components may cause noise
and vibration, inadequate air flow, or a blockage that will
degrade the system cooling.
2.1.11 Bus Headliners
Bus ceilings
(perforated) must be sealed with a non-porous
insulating material in the areas that will be covered by
ducts prior to installation of the ducts to the ceiling.
Failure to seal these noise abatement head-
liners (perforated) will allow dissipation of
the air and marginal cooling.
2.1.12 Mounting Hardware
All Carrier Transport Air Conditioning evaporators are
supplied with the proper mounting hardware. Never
substitute mounting hardware without the permission of
Carrier Transport Air Conditioning. Proper mounting
procedures are supplied with every evaporator.
Use of substitute hardware or failure to fol-
low the installation instructions may result
in structural fatigue and/or breakage.
2--1
with noise abatement
CAUTION
CAUTION
headliners
T--311