Carrier Em1 Manual

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2-13
Figure 2-27 Punching out Louver HolesFigure 2-28 End Cap With Louver
Figure 2-29 EM-9 Ducted Evaporator - Location - Completed Assembly
Figure 2-30 School Style Ducting-Passenger SideFigure 2-31 School Style Ducting-Drivers Side 
						

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2-14
Figure 2-32 Side Mounted Hose Routing
(Using 45°
°° °Angles)
Figure 2-33 Side Mounted Hose Routing (Straight) 
						

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2-15 2.5 EM-17 EVAPORATOR
The EM-17 is available in single and dual loop
applications. Due to the weight and size of the
evaporator assembly it is recommended that this type
evaporator and accompanying condenser and electrical
controls be installed only by OEM’s (Original Equipment
Manufacturers).
Reinforced mounting channels must be welded to thebus roof bows in order to support the evaporator
assembly. Examples of this application have been given
below (See Figure 2-34).
Before attempting to install this type system, it is
strongly advised that you contact Carrier Transport Air
Conditioning Technical Service Hot Line for assistance
(1-800-450-2211).
Figure 2-34 EM-17 INSTALLED
2.6 IW-1, IW-2, IW-7 & IW-14 EVAPORATORS
The IW (In-Wall) evaporator assemblies are designed to
be installed in the rear wall of a bus while it was being
assembled at an OEM’s location. There are also OEM
applications where the IW has been installed in the front
of a bus.
This type evaporator is not recommended for after
market applications.2.7 EM-20, EM-21 & EM-22 EVAPORATORS
EM-20, EM-21 and EM-22 are floor mounted
heating/cooling units normally used on ambulances
and/or armored trucks. For installation instructions and
or information on these type systems contact Carrier
Transport Air Conditioning Technical Service Hot Line
(800) 450-2211. 
						

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3-1
SECTION 3
CONDENSERS
3.1 INTRODUCTION
3.1.1 Description
Condensers are normally located in the bus skirt or on
the bus roof. Their primary function is to reject heat from
the refrigerant to the exterior of the vehicle.
3.1.2 Location
Assure that the condenser will mount properly in the
location of choice. Always try to fit skirt mounted
condensers between the front and back wheels and
always as close to the bus skirt as possible. This
assures adequate air flow and avoids recirculating heat
from under the bus.
3.1.3 Cap Plugs
Carrier Transport Air Conditioning condensers are
leak-checked and shipped with a charge of inert gas to
keep the coil dry. Do not remove any of the caps/plugs
from the condensers until you are ready to hook up the
refrigerant lines.
3.1.4 Protection
When a skirt condenser must be mounted close to a
vehicle wheel, CarrierTransport Air Conditioning
recommends that the condenser be protected from
wheel-sling, (mud, water road salts,etc.) by a splash
guard. Failure to properly locate and protect the
condenser may cause a variety of problems, from
corrosion to inefficient cooling, pressure increases, and
compressor failure.
3.1.5 Obstructions
To function efficiently the air inlet and outlet of the skirt
condenser must be free of any obstruction, including the
bus chassis rail and the bus skirt. Failure to have free air
flow will restrict the rate of heat rejection causing apressure rise in the system. Excessive pressure may
cause cooling inefficiencies and possible compressor
failure. The bus skirt must always be cut out when
installing a skirt mounted condenser.
3.1.6 Skirt Supports
Whenever a bus skirt support must be removed in order
to mount the condenser, the skirt must be resupported
by the condenser assembly or by attaching an alternate
skirt support. All skirt mounted condenser screens must
be flat against the vehicle skirt.
3.1.7 Mounting (Skirt)
All Carrier Transport Air Conditioning condensers are
supplied with the proper mounting hardware. Never
substitute mounting hardware. Always insure that the
skirt mounted condensers are mounted on a flat surface
and are level. Carrier highly recommends that “OEM’s
(original equipment manufacturers) provide condenser
mounting brackets in order that the bus floor does not
have to be drilled through when mounting/installing the
skirt condenser.
3.1.8 Mounting (Rooftop)
When mounting a roof top condenser, alterations must
be made to the bus roof. The installation instructions
include sealing instructions which must be followed.
Failure to follow these instructions will allow water to
enter the passenger compartment.
3.1.9 Voltage
Carrier Transport Air Conditioning condensers are
designed to operate efficiently at 12.5 and 25 Volts
respectively. Condensers operating at less than the
required voltage will cause the fans to run slower and
may cause pressure buildup and possible compressor
failure. 
						

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3-2 3.2 CONDENSERS
Condensers are normally located on the outside of the
vehicle. Their primary function is to reject heat absorbed
by the refrigerant from the passenger compartment to
the outside air. Condensers are normally located on thevehicle skirt or on the roof. If space in the vehicle skirt is
a problem, the CM-2 and CM-3 can be stacked on each
other with a kit available from Carrier Transport Air
Conditioning (Refer to paragraph 3.7) Carrier Transport
Air Conditioning condenser assemblies are listed in
Table 1-5.
Ta b l e 3 -1CONDENSERS (Used With GEN 4 And GEN 5 Series)
Component
Ty p eCFM
(Approx)AmpsWeightBTU Heat
Rejection
CM-2SKT [email protected]
16@25V66 Lbs.57,000
CM-3SKT [email protected]
24@25V76 Lbs.76,000
CM-4SKT OR RF [email protected] Lbs.43,000
CM-5SKT MT600041@24V202 Lbs.162,000
CM-7RF [email protected]
12@25V87 Lbs.76,000
CM-11RF [email protected] Lbs.57,000
KR-4RF [email protected]
22@25V187 Lbs.130,000
CM-14SKT [email protected]
30@25V95 Lbs.85,000
CM-2 STKD (2 ea)SKT [email protected] Lbs.114,000
CM-3 STKD (2 ea)SKT [email protected] Lbs.152,000
Legend:
CM - Condenser Module
KR - Rooftop (4 Fan)
RF - Roof Mounted
SKT - Skirt Mounted
STKD - Stacked
3.3 CM-2, CM-3, CM-4, CM-5, & CM-14 SKIRT-
MOUNTED CONDENSER ASSEMBLIES
The Carrier Transport Air Conditioning Condensers
listed in paragraph 3.3 are designed so they can easily
be installed in the skirt of a bus, while other condenser
assemblies are mounted on the bus roof.
Check the location selected under the bus for any
obstacles that might interfere with the proper installation
of the condenser assembly.
Using the dimensions listed in Table 2-1, determine that
the condenser assembly will fit safely and securely in
the desired location.
Table 3-2 SKIRT MOUNTED CONDENSERS
Condenser
A(width)B(height)C(depth)
CM-235.75 inch10.312 inch15.75 inch
CM-348.0 inch10.312 inch15.75 inch
CM-439.0 inch8.38 inch14.50 inch
CM-587.5 inch15.25 inch15.281 inch
CM-1461.0 Inch10.37 Inch15.75 Inch
To install the skirt mounted condenser assemblies
utilize the following installation procedures:
a. Unpack the condenser and check for obvious dam-
age.
b. Make a condenser mounting template from card-
board or other thin material.c. Lay condenser upside down on the template material.
d. Align the front of the condenser with the straight edge
of the template material.
e. Mark all of the oblong mounting holes located in the
front and rear of the condenser assembly.
f. Mark outer edges of the condenser assembly on to
the template material.
g. Remove condenser from template material and cut-
out template and oblong mounting holes.
h. Mark center of template.
i. Using the condenser template under the vehicle, find
the optimum location between the front and rear
wheels of the vehicle and mark the mounting holes.
Note
The condenser assembly should contact as
many of the floor supports (stringers) as pos-
sible, while hitting the least amount of skirt sup-
ports.
Note
Always attempt to use at least one of the ve-
hicles floor supports (stringers) to mount the
condenser assembly.
j. Drill pilot holes up through the bus (vehicle) floor.
Caution
Make sure there is nothing installed where
you are going to drill through the bus floor.
k. Using the pilot holes, drill 7/16 inch holes through the
bus floor or stringers. See Figure 3-1. 
						

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3-3 NOTE
To safely attach/mount the CM-2 it will require a
minimum of 4 bolts, while the CM-3 requires 6
bolts.
NOTE
Block spacers or jam-nuts may be required if
the condenser mounting area is not tight
against the bus stringers. See Figure 3-3.
Figure 3-1 3/8 Inch Carriage Bolts Thru Floorl. Mount the condenser using 3/8 inch diameter hard-
ware. See Figure 3-2.
m.Install grill/screen on condenser assembly or skirt of
bus, depending on application.
n. Connect discharge and liquid lines. Refer to Section
4, hose routing.
o. Connect electrical harness to condenser. Refer to
Section 5, electrical.Figure 3-2 Condenser Mounted With Hardware
CONDENSER
SCREENSKIRT
MOUNTING HARDWARE
SUPPLIED BY INSTALLERFLOOR MEMBERBUS FLOOR ALTERNATE MOUNTING
BLOCK SPACER REQUIRED IF NO
FLOOR MEMBER AT FASTENER LOCATION
(STRINGER)
POP RIVER
3/16 STEEL
CM-3:(6) 3/8-16 GRADE 5 BOLTS CM-2:(4) 3/8-16 GRADE 5 BOLTS NOTE:MINIMUM MOUNTING HARDWARE REQUIRED
MOUNTING HARDWARE
SUPPLIED BY INSTALLER
Figure 3-3 Installation Drawing (Typical Skirt Mounted) 
						

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3-4
Figure 3-4 CM-3 Condenser Mounting (Typical)
Figure 3-5 CM-2 Condenser Mounted on an Extended Roof Van (Custom)
Figure 3-6 CM-3 Mounted In Cut-A-Way Chassis 
						

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3-5 3.4 Cm-5 CONDENSER
The Carrier Transport Air Conditioning CM-5
Condenser is designed to be installed in the skirt of the
bus.
To install the CM-5 Condenser utilize the installation
procedures found in paragraph 3.3.Refer to the installation drawing enclosed with the
condenser or see Figure 3-7.
Note
Because of the size and weight of the CM-5
condenser assembly, ten (10) bolts are re-
quired to safely install it to the bus floor string-
ers, Five (5) in the front and (5) in the rear.
ALTERNATE MOUNTING
FLOOR
SKIRT
POP RIVET, 3/16” STEEL
OR SELF DRILLING SCREWS
GRILL (3)
MOUNTING HARDWARE
SUPPLIED BY INSTALLER
MOUNTING HARDWARE
SUPPLIED BY INSTALLER
CM-5(10) 3/8-16 GRADE 5 BOLTS NOTE:MINIMUM HARDWARE REQUIRED
SPACER
CM-5 CONDENSER
Figure 3-7 CM-5 Installation Drawing 
						

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3-6 3.5 Cm-7, CM-11 ROOFTOP CONDENSER
ASSEMBLIES
The Carrier Transport Air Conditioning CM-7 & CM-11
condensers are designed to be installed on the roof of
the bus.
To install a rooftop condensers utilize the following
installation procedures:
a. Select a location on the bus roof where the mounting
channels will span at least two roof bows.Note
The ideal location will be close to the evaporator
inside the bus as well as spanning two roof
bows.
b. Remove the rooftop condenser from the shipping
box. Locate the two mounting channels, 4 mounting
feet and mounting hardware.
c. Remove rooftop cover. Install four mounting feet with
inclosed hardware. Refer to inclosed installation
drawing or see Figure 3-8.
Condenser Frame
Bus Roof Bow Bus Outer Skin Mounting Channel 1/4 In. Flat Washer
1/4-20 ESNA1/4 In. Spacer
Bolt,1/4-20X1In.
Condenser Frame Mounting FootMounting Foot 1/4 In. Flat Washer
1/4-20 ESNA1/4 In. Spacer
1/4 In. Spacer
Bolt,1/4-20X1In.Bolt, 3/8-16 X 1-1/4 In.
(Torque to 20 Ft. Lbs.)
3/8 In. Lock Washer
3/8 In. Flat Washer
3/8 In. Lock Washer
TOPVIEW
(Angle may have to be adjusted)
Figure 3-8 Installing Mounting Feet & Mounting Channels
d. Install the two mounting channels to the mounting
feet with the enclosed hardware.
Note
Do not tighten the mounting hardware at this
time. You may have to make adjustments to the
mounting feet and rails later.e. Carefully place the condenser at the predetermined
location on the bus roof. Center the condenser side-
to-side on the bus roof.
f. Trace around both mounting channels.
g. Mark where the feed-thru-plate will be located. This is
where the discharge and liquid line will be connected.
Refer to the enclosed installation drawing or see
Figure 3-9.
Liquid line (#8 hose) - to evaporatorOptional configuration of remote
mounted filter drier-sightglassFeed-Thru-Plate
1/2 in.O-Ring
(4 places)
Filter Drier/Sightglass
W/Moisture Indicator
1/2 in.O-Ring
(2 places)Drill 13/64 Dia. holes. Use 3/16 In.
rivets thru outer skin, (8 places).
Apply sealant to plate & rivet heads
to prevent water leaks.
BUS ROOF
Figure 3-9 Attaching To Feed-Thru-Plate & Remote Filter Drier 
						

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3-7 h. Remove mounting channels from condenser mount-
ing feet.
i. Drill 13/64 In. Dia. holes thru the bus roof outer skin
and roof bows using the mounting channel holes as a
guide. See Figure 3-10.Note
It is recommended that a drill stop be used
when drilling through the bus roof.
j. Apply sealant around all the holes and the mounting
channels. Place the channels on the bus roof.
Position mounting channel so it
spans across a minimum of two
roof bows.
Drill a 13/64 dia. hole. Use 3/16 in.
steel rivets located thru each roof bow
a minimum of 8 places Drill a 13/64 Dia. holes. Use 3/16 In.
rivets thru outer skin. Minimum of 20
places
Figure 3-10 Attaching Mounting Channels To Bus Roof
k. Using 3/16 In. Dia. steel rivets, attach the mounting
channels to the bus roof.
l. Where previously marked carefully cut a 3 X 4 Inch
hole thru the bus roof and ceiling. This is where the
feed-thru-plate will be attached.
m.Place the feed-thru-plate over the cut-out. Modifica-
tions may be needed in order for the plate to fit proper-
ly.
n. Drill 13/64 In.Dia. holes in the bus roof using the holes
in the feed-thru-plate as a guide. Use all 8 holes.
o. Apply sealant around all the holes and the plate.
p. Using 3/16 In. Dia. steel rivets, attach the feed-thru-
plate to the bus roof.
q. Seal around the feed-thru-plate and the mounting
channels. Apply sealant to all the rivet heads to pre-
vent water leaks.Note
The mounting foot angle may have to be ad-
justed in order that it sits flat on the mounting
channels. See Figure 3-8.
r. Place the condenser back on to the mounting chan-
nels. The center of the condenser must be close to
the bus roof but not touching it. Adjust the mounting
legs up or down for the correct height. Refer to the
installation instructions enclosed or see Figure 3-11.
Note
Remember to lubricate all fittings, O-Rings, and
refrigerant hose with mineral oil before attach-
ing components. All refrigerant O-Ring fittings
must be torqued to 30 ft. lbs.
s. Connect the condenser discharge and liquid lines to
the feed-thru-plate fittings.
t. Securely mount (clamp) the filter drier/sightglass as-
sembly to the ceiling at the rear of the evaporator as-
sembly.
1In.
Drill 0.28 Hole (8 Pls)
NOTE: Use Mounting Leg as a Template.50 In.
Adjust Leg to Correct Height - Then Install Hardware
Figure 3-11 Adjusting Mounting Foot Height