Carrier Em1 Manual

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3-8 u. Assemble, than attach liquid lines from the remote fil-
ter drier/sightglass assembly to the liquid line fitting
on the feed-thru-plate and the evaporator assembly
(See Figure 3-9).
v. Route suction line from the evaporator and discharge
line from the condenser per instructions provided in
Section 4, Hose Routing.
Note
Route the condenser electrical harness through
the feed-thru-plate before bolting on the con-
denser cover.
w.Bolt rooftop cover on to rooftop frame with hardware
supplied.
x. Clean condenser cover with a mild cleaning solution
and clear all debris from the roof of the bus.
3.5.1 Connecting to Side-Mounted Evaporators
The preceding steps are for connecting a rooftop
condenser assembly (CM-7 or CM-11) to a rear
mounted evaporator assembly. The standard
feed-thru-plate should not be used with side mounted
evaporators. Refrigerant hoses should be routed
between the inner and outer skins of the bus ceiling and
roof. When connecting to side mounted evaporators
utilize the following procedures:
a. Follow steps a. through f. from paragraph 3.5.
Note
When drilling into the bus ceiling and pulling the
refrigerant hoses, care must be taken to re-
move as little insulation as possible from the
bus ceiling.
b. Mark where the feed-thru-plate would normally be lo-
cated and cut a 4-1/2 In. hole in roof skin only.
c. Cut 4-1/2 In hole behind the side mounted evapora-
tor, or, if ducted system, within the duct area.
d. Use a fish-tape or wire to pull the liquid and discharge
lines up to the condenser assembly from inside the
bus.Note
Both inside and outside cut-outs must be pro-
tected with trim-lock or similar material to help
keep the refrigerant hoses and harness from
chaffing.
e. Using the optional hose cover transition (Part #
58-62028-00) allows for a smooth transition from the
bus skin to the condenser assembly’s liquid and dis-
charge hook-ups, plus it is easier to seal against wa-
ter leaks.
f. If the optional hose cover transition (see Figure 3-12)
is not used, the roof hole must be sealed to prevent
water leaks.
g. Drill a1-1/8 In. Dia. hole in the hose cover for the #8
Quick-Click refrigerant hose. Push grommet part #
58-00065-36 into the hole (see Figure 3-12).
h. Drill a1-3/8 In. Dia. hole in the hose cover for the #10
Quick-Click refrigerant hose. Push grommet part
#AC801-327 into the hole.
i. Drill a .81 In. Dia. hole in the hose cover for the con-
denser harness. Push grommet part #58-00065-22
into the hole.
i. h.
g.
Figure 3-12 Hose Cover Transition Cut-Outs
j. Push the refrigerant hoses and harness through the
appropriate grommets in the hose cover transition.
k. Cut hose to length and install the appropriate Quick-
Click fittings. Connect to the condenser liquid and dis-
charge lines.
l. Center the hose cover transition over the cut-out in
the bus roof. Drill 13/64 In. Dia. holes thru the hose
cover and bus roof (7 places).
Discharge Line
From CompressorLiquid Line
To Evaporator
Roof Bow
Roof BowMounting Channel Mounting FootHose CoverBus Roof
Figure 3-13 Hose Cover Transition & Refrigerant Hose Connections 
						

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3-9 m.Remove any debris from the hose cover and cut-out.
Apply a bead of sealant to bottom of the hose cover.
Rivet hose cover in place with 3/16 India. rivets.
n. Apply sealant to all the rivet heads and all areas open
to the interior to prevent water leakage.
o. Route suction line from the evaporator and discharge
line from the condenser per instructions provided in
Section 4, Hose Routing.Note
Connect the electrical harness that was routed
through the hose cover transition before bolting
on the condenser cover.
p.Bolt rooftop cover on to rooftop frame with hardware
supplied.
q. Clean condenser cover with a mild cleaning solution
and clear all debris from the roof of the bus. 
						

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3-10 3.6 KR-4 ROOFTOP CONDENSER ASSEMBLY
The Carrier Transport Air Conditioning KR-4 condenser
is designed to be installed on the roof of the bus.
To install the KR-4 rooftop condenser utilize the
following installation procedures:
a. Select a location on the bus roof where the condenser
and/or mounting channels will span three roof bows.
(Three (3) are preferred, but never no less than two
(2) roof bows.
Note
The ideal location will be close to the evaporator
inside the bus as well as spanning three roof
bows.
b. Remove the rooftop condenser from the shipping
box. Locate the two mounting channels (if used) and
mounting hardware.
Note
Certain applications will not require the mount-
ing channels due to the contour of the bus roof.
c. Remove rooftop cover. Install the mounting rails (if
used) with the inclosed hardware. Refer to inclosed
installation drawing or see Figure 3-14.
Note
Do not tighten the mounting channel hardware
at this time. They will have to be removed later.
d. Carefully place the condenser at the predetermined
location on the bus roof. Center the condenser side-
to-side on the bus roof. Determined if the mounting
channels are needed at this time. See Figure 3-15
and Figure 3-16.
CAUTION
This condenserassembly must contact the
bus roof in the center. If not, damage will oc-cur. Consult factory as optional mounting
may be required.
e. Trace around both mounting channels or condenser
mounting surface. See Figure 3-14.
f. Remove mounting channels (if used) from condenser
assembly.
Note
It is recommended that a drill stop be used
when drilling through the bus roof.
CAUTION
All 3/16 and 1/4 In. rivet engagement thick-
ness (grip range) must be between 0.080
and 0.625. Using rivets other than those
specified may allow the condenserassem-
bly to come loose from the bus roof.
g. If using mounting channels drill (6 places each rail)
13/64 In. Dia. holes thru the bus roof skin using the
mounting channel holes as a guide. Apply sealant to
the mounting channels or bus roof. Use 3/16 In. Dia.
steel rivets to attach mounting channels to bus roof.
Drill 17/64 In. Dia. holes thru the mounting channels
and bus roof bows. Apply sealant to 1/4 In. Dia. steel
rivets and rivet to the roof bows (minimum of two riv-
ets per roof bow). Apply sealant to the rivet heads and
around the mounting rails to prevent water leaks. At-
tach condenser to mounting channels using the en-
closed hardware. Torque to 20 Ft. Lbs. Refer to en-
closed installation drawing or see Figure 3-17.
h. If not using mounting channels, remove the condens-
er assembly to expose outline tracing. Apply sealant
where the condenser will be installed. Drill 17/64 In.
Dia. holes thru the bus roof skin (6 places each side)
and the roof bows (minimum of two rivets per roof
bow). Apply sealant to 1/4 In. Dia. steel rivets and riv-
et to the roof and roof bows. Apply sealant to the rivet
heads and around the mounting rails to prevent water
leaks. Refer to enclosed installation drawing or see
Figure 3-18.
Without Mounting Channel
With Mounting Channel
Bus roof outer skin
Roof bow Sealant 1/4 In. steel
monobolt.Bolt, 3/8-16 X 1-1/4 In.
4 per side.
3/8 In. flat washer
3/8 In. flat washer
Mounting channelBus roof outer skin
Roof bow
Figure 3-14 Mounting Options 
						

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3-11
Roof Bow
Center of condenser assembly center must contact bus roof
Figure 3-15 Condenser Mounted Without Mounting Channels
Roof Bow
Center of condenser assembly center must contact bus roof
Bus RoofMounting
Channel
Figure 3-16 Condenser Mounted With Mounting Channels
Roof Bow Roof BowApply sealant to unit mounting surface
and rivet heads to prevent water leaksBus Roof
Figure 3-17 Condenser Mounted Without Mounting Channels (Side View)
Apply sealant to unit mounting surface
and rivet heads to prevent water leaks Roof BowBus Roof
Mounting
ChannelRoof Bow
Figure 3-18 Condenser Mounted With Mounting Channels (Side View)
3.6.1 Connecting To The Evaporators
When connecting to the evaporator(s) utilize the
following procedures:
a. Condenser assembly inlet and outlet should have
been positioned as close to the evaporator assembly
as possible (rear or side mount).
b. Follow procedures in paragraph 3.5 and 3.5.1.c. After connecting refrigerant lines and condenser har-
ness(s) install the condenser cover with hardware
provided.
d. Clean condenser cover with a mild cleaning solution
and clear all debris from the roof of the bus. 
						

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3-12 3.7 CM-2 AND CM-3 STACKED CONDENSER AS-
SEMBLIES
The Carrier Transport Air Conditioning stacked
condensers are designed to be installed in the skirt of
the bus when there is insufficient room for a standard
installations.
To install Stacked Condensers utilize the following
installation procedures:
NOTE
The top and bottom condenser assemblies can
be assembled as one then installed as a com-
plete stacked condenser assembly to the bus
stringers.
CAUTION
Condenserassemblies must be properly
installed using graded hardware. The CM-2
condenserassembly requires at least 4
bolts and the CM-3 requires at least 6 bolts.
a. Install top condenser to the bus stringers (floor) as de-
scribed in paragraph 3.3
b. Assemble bottom condenser assembly to the top
condenser assembly with the hardware supplied inthe appropriate (2 or 3) stacked condenser kit. Refer
to the enclosed installation drawing or Figure 3-19
and Figure 3-20.
c. Place air inlet stiffener over air inlet bracket and
loosely attach to the top condenser assembly. Repeat
on other side of assembly.
d. Loosely attach air outlet bracket to top condenser as-
sembly. Repeat on other side of condenser assembly.
e. Attach bottom condenser assembly to top assembly
using the air inlet stiffener bracket, air outlet brackets,
and the required hardware.
f. Attach block-off plate to both air inlet brackets.
g. Slide air inlet bracket and block-off plate against the
bus skirt.
h. Tighten all bolts.
NOTE
The CM-3 Condenser assembly requires the
installation of a front bracket. See Figure 3-20.
This bracket helps to support the bottom con-
denser assembly.
i. Install condenser screens (2) to the bus skirt, air inlet
bracket and block-off plate.
FLOOR MEMBER (STRINGER) BUS FLOOR
CHASSIS
RAIL
Top Condenser
Bottom Condenser
Bus Skirt Air Outlet BracketAir Inlet Stiffen
Air Inlet Bracket
Figure 3-19 Stacked Condenser Assembly (Side View) 
						

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3-13
Front Bracket
Block-Off Plate
Air Inlet Bracket
Air Inlet Bracket
Figure 3-20 Stacked Condenser Assembly (Bus Skirt View) 
						

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SECTION 4
HOSE ROUTING
4.1 INTRODUCTION
All bus air conditioning systems use a network of
refrigerant hose and fittings to connect the major
components and carry the refrigerant gas and liquid
through the system.
4.1.1 Planning
Extreme care must be used when piping a bus. Plan the
routing of the hose prior to the installation, being careful
to avoid sources of high heat and sharp edges. If the
hose is routed near any heat source it should be
protected with a heat-resistant insulation. When hoses
are run through sheet metal or other sharp parts of the
frame, the hose should be protected by grommets or
clamped off in a manner that prevents chaffing. Failure
to protect the hose may result in leaks, loss of refrigerant
and cooling, and possible compressor damage.
4.1.2 ServiceLoop
When refrigerant hoses are attached to any component,
it is highly recommended that the hoses are not pulled
tight. Use a service loop at the compressor and extra
hose at other locations to provide strain relief. This will
allow the engine and road vibration to be absorbed by
the hose and not the fittings. Failure to give strain relief
may result in leaks or fractured fittings. Do not, however,
leave the extra hose unsupported.
4.1.3 Dual Systems
When a bus has dual (2) systems, care must be taken to
assure that the electrical system and hose routing are
independent of each other. Connections of the piping for
one system to the electrical signals from the other may
result in failures to both systems through
miscommunication with the pressure switches. Marking
both ends of the hose assembly for identification is
recommended.
4.1.4 Connection Lubrication (Mineral Oil)
System hose connections, fitting threads, and “O”
-Rings must always be lubricated with mineral oil. Never
use PAG or POE oils. Failure to lubricate the system
“O”-Rings and fitting threads or the use of an improper
lubricant may lead to torn seals, local corrosion, and
leaks.
4.1.5 Quick-Click Hose & Clamps
It is highly recommended that all installations be
performed using Carrier Transportation Air Conditioning
“Quick-Click” hose and fittings.
4.1.6 Barrier Type Hose & Fittings
If “Barrier” type hose and fittings are used, it is highly
recommended that you review Carrier Transport Air
Conditioning Hose Crimping Procedures (Form No.
310-011). The setup, operation and equipment
maintenance are all critical. Failure to crimp properly will
result in immediate leaks or leaks that become evident
due to heat and vibration. When using beadlock type
fittings it is critical to have initial interference between
the hose inside diameter and fitting tube outside
diameter. Use of a combination that has clearance
between components will result in a much higher
probability of leaks.4.2 EVAPORATOR HOSE ROUTING-INSIDE THE
BUS WALL
Always keep hose capped until ready to connect to a
system component (see Figure 4-- 1).
Figure 4--1 Quick-Click Hose (Capped)
Cutaway bus hose routing will normally be routed
through the bus floor, up the lower wall (see Figure 4-- 2),
and then behind the upper off-set rear wall. This type of
routing must be accomplished before the evaporator is
mounted to the bus ceiling. On some buses the hose,
harness, and drain lines can be routed (hidden) behind
the lower wall also.
Figure 4-- 2 Bus With Rear Seat Removed
1. Determine which side of the vehicle the hoses
should be routed; the drivers side or passenger side. 
						

							T--3114-2 2. Determine what route the hoses will take. Take into
consideration there are going to be obstacles that
the hoses may have to be routed around, such as
seats, wheelchair lifts, windows, etc.
3. Lay out the hose cover backs in the position that they
eventually will be installed, and mark their position
(see Figure 4-- 3). Mark the sides and where they
stop at the floor and wall. This will give you an outline
where the holes for the hoses should be placed.
Figure 4--3 Hose Back Positioning
Before drilling holes for the hoses in the wall or through
the floor, make sure there are no electrical harnesses,
braces, etc. in the path of the hose routing and hole saw.
4. Drill a 3/16 inch pilot hole in the center of where you
are going to drill the two 1 1/2 inch holes. This will
show you if you can safely cut the two 1 1/2 inch
holes in the floor.
5. Drill two 1-1/2 inch holes side by side within the hose
cover markings (see Figure 4--4).
Figure 4--4 Hole-Saw Cuts in Floor
6. Saw out any material remaining between the two
holes, leaving an oblong hole to route the hoses
through (see Figure 4-- 5).
Figure 4--5 Hole-Saw Cuts Joined
Repeat steps 1. through 6. to obtain access to the wall or
floor, depending which one you start with.
Figure 4-- 6 Rear Wall Access
7. Remove any sharp edges from around the holes to
prevent hose cutting and/or chaffing.
After holes are drilled, sawed and deburred, you are
ready to mount the hose cover backs using common
fasteners such as screws or pop rivets (see Figure 4-- 7
& Figure 4-- 8). 
						

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Figure 4--7 Hose Cover Back
Figure 4-- 8 Hose Cover Backs On Rear WallCaution
When drilling into the vehicle wall, always
use a drill stop to help protect against dam-
aging any wiring that might be located be-
hind the wall.
Installation Hint
To help keep hoses, harness, and drain lines
secure and in the center of the hose covers,
3/16 inch holes can be drilled in the hose cover
backs. Insert Tie-Wraps through the holes be-
fore securing the hose cover backs to the wall
(See Figure 4-- 14).
8. Drill a 3 inch hole in the vehicle wall in order to rout
the hoses and harness to the evaporator area.
9. Remove (deburr) any rough edges from around the
cut-out.
Using a small piece of “Trim-Loc” or similar material
around the cut-out will help protect the hoses and
harness from chaffing and/or cutting. (See Figure 4-- 9).
Trim-Lock
Figure 4-- 9 Access Hole With Trim-Lock
10. Route the hoses and harness at this time.
Protection
Figure 4--10 Hoses Routed Through Access
Before fastening to the hose cover backs, protect the
hoses and harness wherever they go through the floor
or wall (see Figure 4-- 10 & Figure 4-- 11) 
						

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Protection
Figure 4--11 Hoses Routed Through Floor
A piece of scrap drain hose or heater hose, split down
the middle, can be used for protection.
11. After hoses and harness are protected, secure them
to the hose cover backs with the Tie-Wraps.
Figure 4-- 12 Hoses/Harness Secured With
Tie-Wraps To Hose Cover Back