Carrier Em1 Manual

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2-3 Table 2-3 DISTANCE TO BACK WALL (GEN 4)
Gen 4 Evaporator
Distance to back wall
EM-17 Inches
EM-27 Inches
EM-34.5 Inches
EM-67 Inches
EM-148.75 Inches
Table 2-4 DISTANCE TO BACK WALL (GEN 5)
Gen 5 Evaporator
Distance to back wall
EM-14.125 Inches
EM-24.125 Inches
EM-34.125 Inches
EM-74.125 Inches
Figure 2-2 Measurement To Wall (GEN 4)
4.125 In.
BUS REAR WALL
Back of Top Panel
Filter Assembly
Return Air
Mounting HolesMounting Holes
Cover
Figure 2-3 Measurement To Wall (GEN 5)
8. Locate center of bus ceiling and mark.
9. Centering the template against back wall and ceiling,
mark the bus ceiling and wall for evaporator mounting
holes and drain lines.
10.Using a 3/16 drill bit, drill 4 holes through the bus ceil-
ing. The smaller bit will allow you to check the angle of
the hole and where you have exited the bus roof. If the
angle is incorrect, the 3/16th hole is easily repaired
with a pop-rivet.
11.After determining the pilot hole is correct enlarge the
4 holes to 7/16 inch. See Figure 2-4.
Figure 2-4 7/16 Inch Holes in Bus Roof12.Matching holes in reinforcing rails to holes in bus
roof, drop 3/8 inch carriage bolts through mounting
rails and the roof. The carriage bolts should drop
through the roof easily. You may have to open the
holes slightly, Do not force the bolts through the roof
or ceiling.
Figure 2-5 Carriage Bolts & Sealant
13.Pull reinforcing rails and carriage bolts away from
bus roof. Apply a bead of sealant down the center of
each rail and under the carriage bolt heads. See
Figure 2-6 and Figure 2-7.
Figure 2-6 Sealant Pattern on Mounting Channel
Figure 2-7 Carriage Bolt Sealing 
						

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2-4
Figure 2-8 Locking Pliers Clamped to Carriage
Bolts
Installation Hint
In order to keep carriage bolts from being forced
out of the reinforcing rails on the bus roof, use
small locking pliers to hold the bolts in place
(See Figure 2-8). Tighten the bolts until the
evaporator is almost touching the locking pliers
(See Figure 2-9). Remove the locking pliers
and continue tightening as described in step 14
Installation Hint
For ease in installing the evaporator cover on
buses with heavily contoured ceilings, insert
spacers (wood or metal) between the evapora-
tor panel and bus ceiling. See Figure 2-17, item
j Without these spacers you may need to trim
the top side edges of the evaporator cover.
14.Mount evaporator using 3/8 inch hardware and tight-
en to bus ceiling. Do not over tighten, as this will dis-
tort either the bus ceiling and/or roof.
Figure 2-9 Locking Pliers & Evaporator
Figure 2-10 Evaporator Mounted to Flat Ceiling
Figure 2-11 Mounting Channel Sealing
15.Seal outer edge of reinforcing rails. Improper sealing
of the reinforcing rails will allow water to leak into the
passenger compartment (See Figure 2-11).
16.If refrigerant hose and wiring harness were previous-
ly routed through the bus wall they can be connected
at this time. If not, the hose and harness, plus the
drain lines must be surface routed on the bus wall us-
ing the hose cover kit provided. Refer to Section 4 for
detailed instructions regarding hose and harness
routing.
17.After the liquid and suction lines have been con-
nected and you are sure there are no leaks, the suc-
tion fitting and the block valve must be wrapped with
“no-drip” tape in order to keep them from dripping
condensate into the passenger compartment.
Figure 2-12 Block Valve Insulation
18.Connect two drain lines to the EM-1 evaporator drain
pan assembly. Secure both drain lines with the
clamps provided with the system. One drain line can
be routed with the refrigerant hose and wiring har-
ness, while the other must be routed to the opposite
side of the bus. Drain lines must always run downhill,
and care must be taken not to kink the drain lines.
Plastic 90°elbows may be required to keep drain lines
from kinking. If in doubt, use the elbows supplied. 
						

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2-5 19.After the drain lines have been routed to the outside
of the bus they should be cut approximately 6 inches
below the floor. Install condensate valve over the
ends of the drain lines. This prevents air from being
drawn through the lines into the evaporator which will
stop the flow of condensate from the drain pan. It also
prevents insects from entering the drain lines.
Drain Hose
Clamp, Drain Hose
Condensate Valve
Figure 2-13 Drain line & Condensate Valve
20.Fit evaporator cover over unit. If evaporator cover
needs no trimming mount cover with the hardware
provided.
Figure 2-14 Installed Evaporator
21.With the cover removed, note the distance between
the top of the unit and the contour of the bus ceiling. If
this distance is more than 1 inch, it must be closed off
to prevent any recirculation over top of the evapora-
tor. Use the evaporator trim strip provided. Flat or
almost flat ceilings do not require any trim strip.22.Install return air grill to the evaporator cover. Some
trimming could be involved.
Trim this area
Return Air Grill
Figure 2-15 Return Air Grill
23.Clean evaporator and hose covers with a mild clean-
ing solution. Clean all debris from the interior of the
bus.
Figure 2-16 Painted Mounting Channel
24.For aesthetic purposes only, it is recommended that
the exterior reinforcing rails be painted the same color
as the bus exterior.
A typical installation drawing for a GEN-4 front or rear
mounted evaporator is shown in Figure 2-17 and a
completely installed rear mounted evaporator is shown
in Figure 2-18. 
						

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2-6
a
bcd
e fg hi
k
l
m n
j
7/6 inch holes
a. Snap Cap
b. Pan Head Screw
c. Snap Cap washer
d. Trim Strip
e. Flexible Trim
f. Evaporator Cover
g. Evaporatorh. Mounting Channel
i. Carriage Head Bolt 3/8-16 x 4
j. Optional Spacers
k. Drain Line
l. Drain Line Clamp
m. Condensate Valve (Kazoo)
n. Locking Nut 3/8-16
Figure 2-17 GEN-4/5 Front/Rear (EM-1, 2, 6, & 14) Evaporator & Installation Hardware
Figure 2-18 Rear Mount Evaporator - Installed 
						

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2-7
Figure 2-19 EM-6 Rear Mounted In An Extended Roof Van
2.2.2 EM-3 EVAPORATOR GEN 4 OR GEN 5
To install the EM-3 utilize the installation procedures
outlined in Paragraph 2.2 except as noted below. See
Figure 2-20 for a typical EM-3 installation drawing.
NOTE
Threaded rod (3/8-16) is supplied with the EM-3
instead of 4 inch carriage bolts. Depending on
the contour of the bus roof the distance from the
ceiling to the evaporator could be up to 10 inch-
es (Installer purchased 3/8-16 carriage bolts
can be substituted for the threaded rod).
NOTE
Most EM-3 installations will require the addition
of spacers between the ceiling roof and the
evaporator assembly (See Detail A,
Figure 2-20). These spacers will help keep thebus roof and/or evaporator from distorting when
tightening the lock nuts.
WARNING
Do not attempt to modify the EM-3 evapora-
tor top panel. Modifications to the top panel
could structurally weaken the evaporator
assembly, causing system failures and/or
injuries to passengers.
NOTE
Any refrigerant hose and/or electrical harness
that was routed behind the evaporator assem-
bly must be secured to the back wall or ceiling
with insulated clamps. 
						

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2-8
3.75 IN. To Rear Wall
1
23 4
12
Apply Sealant
Side Of Bus
A
Wood
Spacers
Corner Of unit Should
JustContact Bus
Ceiling
1. 3/8 Flat Washer
2. 3/8-16 Hex Nut, Locking3. 3/8-16 Threaded Rod (Cut To Length)
4. Mounting Bar
Figure 2-20 EM-3 Installation Diagram 
						

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2-9 2.3 SIDE MOUNTED EVAPORATOR - EM-1, EM-2,
EM-6, EM-7, & EM-14
To install a side mounted evaporator assembly utilize
the following installation procedures:
a. Un-pack the evaporator and check for any obvious
damage (Refer to Sec 1.8).
b. Check the interior of the bus/vehicle to make sure the
evaporator(s) can be safely and properly installed in
the selected area.
c. Plan refrigerant hose, drain lines, and electrical har-
ness routing.
d Locate and review installation instructions (See
Figure 2-23). Review system piping and wiring dia-
grams for proper hose and fitting size, plus the proper
wiring harness. Refer to Section 4 for detailed instruc-
tions regarding hose and harness routing.
e Locate full-- scale drawing of the side mounted evapo-
rator you are installing. Glue drawing onto cardboard
or other thin material. Cut-out template.
f Hold template to bus ceiling and back wall. See
Figure 2-21.
Rear Mounting Rail
Front Mounting Rail
Figure 2-21 Side-Mount Template
CAUTION
When selecting a location for installing the
evaporator it is highly recommended that
two roof bows are used to secure the
mounting rails.
g. Mark location of front and rear mounting brackets.
h. Insert carriage bolts into the rear mounting bracket
before installing.
i. Install the mounting brackets using steel rivets sup-
plied in the installation kit. Insure all predrilled holes in
mounting rails are utilized.
j. Loosely assemble mounting hardware onto front
hanger brackets as shown in installation drawing and
Figure 2-23.k. Loosely install evaporator assembly onto the front
and rear mounting brackets.
l. Tighten rear mounting hardware.
m.Level evaporator assembly front to rear using a small
level and the 3/8-16 jam-nuts (See Figure 2-22).
n. Tighten all jam-nuts and lock-nuts on front and rear
mounting brackets and evaporator assembly.
o. Connect refrigerant hoses (Liquid and Suction) and
electrical harnesses at this time. Refer to Section 4
for proper routing of hoses and harnesses.
p. After the liquid and suction lines have been con-
nected and you are sure there are no leaks, wrap
(coat) the suction fitting and the block valve with “no-
drip” tape in order to keep them from dripping conden-
sate into the passenger compartment.
Level
No-Drip Tape
Drain Line Elbow
Figure 2-22 Drain Line Elbows
q. Connect two drain lines to the evaporator assembly.
Drain lines must always run downhill, and care must
be taken not to kink the drain lines. Plastic 90°elbows
may be required to keep drain lines from kinking. If in
doubt, use the elbows supplied. See Figure 2-22.
r. After the drain lines have been routed to the outside of
the bus they should be cut approximately 6 inches be-
low the floor. Install condensate (“kazoo”) tubing over
the ends of the drain lines. This prevents air from be-
ing drawn through the lines into the evaporator which
will stop the flow of condensate from the drain pan. It
also prevents insects from entering the drain lines.
s. Fit evaporator cover over unit. The evaporator cover
must be trimmed to fit the contour of the bus ceiling
and wall.
t. Install trim strip to the evaporator cover and side wall.
Some trimming could be involved (See Figure 2-24).
u. Mark and trim the front trim strip. Most trimming will
be along the side of the trim strip.
v. Install evaporator cover using hardware supplied.
w. Clean evaporator and hose covers with a mild clean-
ing solution. Clean all debris from the interior of the
bus. 
						

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2-10
Top Panel
Top Panel
Rear Hanger AssemblyFront Hanger Assembly
Gen 4/5 Evaporator CoverFront Hanger Detail
1
2 3
45 66
7
77 89
810 6
14
13 12
11
Figure 2-23 Side Mount Installation Instructions (Typical)
1. Trim Strip - Front
2. Trim Strip - Rear
3. Rear Hanger Bracket
4. 3/8-16X1 Carriage Head Bolt
5. Spacer, 1/8 Inch
6. Flat Washer
7. 3/8-16 Hex Nut, Lock
8. 3/8-16 Hex Nut
9. Front Hanger Bracket
10. Lock washer
11. 3/8-16 X 6 Carriage Head Bolt
12. 3/8-16 X 2 Hex Head Bolt
13. Front Hanger14 Spacer, 1 inch
Figure 2-24 Side Mounted Evaporator GEN 4 
						

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2-11
Figure 2-25 EM-2 (Gen V) Side-Mount - Free Blow, Installed (Complete) 
						

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2-12 2.4 EM-9 DUCTED EVAPORATOR
The EM-9 evaporator is normally located slightly
forward of the bus center on the drivers side and slightly
rear of the bus center on the passenger side. See
Figure 2-29.
To install the EM-9 ducted evaporator assembly utilize
the installation procedures outlined in Section 2.3, steps
a through r, then continue with the following steps:
NOTE
Because of the ducting that will be installed the
length of the bus, refrigerant hoses and electri-
cal harnesses can enter or exit the bus floor at
any convenient location. Hoses and harnesses
must be bundled and clamped to the bus ceiling
within the confines of the air conditioning ducts.
See Figure 2-26.
NOTE
Drain lines cannot be routed with the refrigerant
hoses and electrical harnesses as shown in
Figure 2-26. Drain lines must exit the evapora-
tor and immediately run down-hill. The drain
lines in Figure 2-26 are routed within the bus
wiring channel to the hose cover.
a. Trim cover to the contour of bus ceiling. Trim around
the hose/harness cover if routed from rear of evaporator
cover. Temporarily install over evaporator assembly.
b. Hold duct section against the evaporator cover,
ceiling, and wire channel (wall).
c. Trace contour of duct end onto evaporator cover.
Do this on both sides of the cover.
d. Cut duct tracing leaving approximately 1/4 inch on
evaporator cover. See Figure 2-26. This allows the duct
section to butt against the evaporator cover.e. Mark and cut the duct section when routing
hose/harness out of the ducting. Insure the hose cover
will completely cover the hole cut into the duct. See
Figure 2-28 and Figure 2-33.
f. Snap a chalk line to insure duct sections are
installed straight on the ceiling and the wall.
g. Starting at the evaporator, temporarily position a
duct section in place.
h. Mark duct section as to where seats are located.
There should be one louver per seat.
i. Using a hydraulic press or hole saw, cut 3 inch holes
where the louvers are to be located, alternating top to
bottom on all the duct sections. See Figure 2-27. Do not
install the louvers until the installation is complete.
j. The rear duct sections should butt against the back
wall of the bus. The front duct sections must be capped.
Trim the end caps to fit inside the forward duct sections.
k. Cut or puncha3inchopening in the drivers end cap
and install a louver assembly. See Figure 2-28.
l. If preferred, trim evaporator, end caps, and hose
covers with trim lock.
NOTE
Optional “school style ducting” is available from
Carrier Transport AC (See Figure 2-30 &
Figure 2-31). Call Carrier Transport Air Condi-
tioning customer service for availability
(1-800-673-2431).
m. Clean evaporator and hose covers with a mild
cleaning solution. Clean all debris from the interior of the
bus.
n. Install louvers in ducts and end cap. See
Figure 2-29 for a complete ducted evaporator
installation.
ClampClamp
Tie-Wrap
Hose Cover
Trim Lock
Wiring Channel
Figure 2-26 EM-9 Ducted Evaporator - Hose & Harness Routing