BS4848ER1

SERVICE BULLETIN
REFERENCE:
Nova Bus Manuals
SECTION:
02: Engine and Cooling
RS NO:
MQR 7621-1834
BS4848ER1
APPLICATION DEADLINE: 2022JL29
CLAIM REFERENCE NUMBER: WB-4848
EFFECTIVE IN PROD.: N/A
SUBJECT:
Electric Cooling Package (ECP) power cable lugs and junction bus bar corrosion.
JUSTIFICATION:
Corrosion problems at the junction bus bar used for the 24 volts power distribution
between the alternator, the super capacitor and the electric fans of the ECP.
LEVEL
DIRECT CHARGES
DESCRIPTION
LABOUR
MATERIAL
TIME
1
Inspecting and cleaning of the power cable lugs and junction bus
bar.
Nova Bus
Nova Bus
1.75h
2
Replacing the damaged or corroded cables and junction bus bar.
Nova Bus
Nova Bus
0.25h
MATERIAL
QTY
PART NO
REV.
DESCRIPTION
REPLACES PART
N°
1
N57807
–
Mount w/ Cable Tie
–
2
N44887
–
Nut Locknyl M6
–
1
N100476
–
Alternator Deflector Bracket
–
LEVEL 1
LEVEL 2 (5% of 10 vehicles)
1
N90588
–
Busbar 3-Stud 650A Assembly
–
1
N91748-01
–
Cable Assembly C1042 4/0 AWG BK-RD
–
1
N94656-01
–
Cable Assembly C1133 4/0 AWG BK-RD
–
1
N94647-05
–
Cable Assembly C1134 4/0 AWG BK-RD
–
Materials will be available within 48 days. To order, please contact Prevost Parts by phone at 1‑800‑771‑6682, by fax at
1‑888‑668‑2555 or by email at [email protected]. Specify document number, quantity of parts required
and shipping address.
DISPOSAL OF PARTS
REMOVED PARTS ARE:
DISCARDED
RETAINED
Yes
–
* Dispose of the unused parts and the defective parts in
accordance with local environmental standards in effect.
REVISION HISTORY
REV.
DATE
NR
2020DE15
Initial release
Yuvaraj J
2021MA28
Level 2 BOM items modified:
- Cable assembly C1133 was N94656-05
- Cable assembly C1134 used for both LB76 & LB77
- Cable assembly C1077 removed for LB77
Devanand
R1
APPROVED BY:
NQF772001 VERSION 3
CHANGE DESCRIPTION
Jean-Nicolas Fournier
Digitally signed by Jean-Nicolas Fournier
DN: cn=Jean-Nicolas Fournier, o=Nova Bus, [email protected], c=CA
Date: 2021.05.28 10:39:21 -04'00'
WRITTEN BY
PAGE 1 OF 12
SERVICE BULLETIN
BS4848ER1
SHOP SUPPLY
4.0 Oz
N8910847
–
Citrus Degreaser
(20 Oz Spray Can, 15 Oz / 425 g Net Wt.)
–
3.2 Oz
N8910848
–
QD Contact Cleaner
(16 Oz Spray Can, 11 Oz / 311 g Net Wt.)
–
4.0 Oz
N8910809
–
Dolph-Spray ER-44 Aerosol Red Air-Drying Varnish
(20 Oz Spray Can)
–
Note:
N8910847 (Citrus Degreaser)
N8910848 (QD Contact Cleaner)
N8910809 (Dolph-Spray ER-44)
1 ea = 20 Oz
1 ea = 16 Oz
1 ea = 20 Oz
4.0 Oz / Bus (0.2 * 20 Oz can)
3.2 Oz / Bus (0.2 * 16 Oz can)
4.0 Oz / Bus (0.2 * 20 Oz can)
40 Oz for 10 buses (4.0 * 10 buses)
32 Oz for 10 buses (3.2 * 10 buses)
40 Oz for 10 buses (4.0 * 10 buses)
2 cans for entire campaign
2 cans for entire campaign
2 cans for entire campaign
CLIENT
ORDER
ROAD NUMBER
VIN (2NVY/4RKY...)
FROM
TO
FROM
TO
QTY
Rochester New York - RTS
LB76
1901
1901
L82J3K9777052
L82J3K9777052
1
Rochester New York - RTS
LB77
1902
1910
L82J4K9777352
L82J3K9777360
9
PAGE 2 OF 12
NQF772001 VERSION 3
SERVICE BULLETIN
BS4848ER1
WARNING
FOLLOW YOUR INTERNAL SAFETY PROCEDURES.
PROCEDURE
1.1.
Park the vehicle on an even surface with transmission on neutral (N).
1.2.
Turn the master control switch to the OFF position and engage the parking brake.
1.3.
Set the master control switch to the STOP position (see figure 1).
Master control switch in
STOP position
Figure 1 - Master Control Switch in STOP Position
1.4.
Set the battery disconnect switch in the battery compartment to the OFF position (see figure 2).
Battery disconnect
switch in the OFF
position
Main power light
turned OFF
Figure 2 - View of Battery Disconnect Switch
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NQF772001 VERSION 3
SERVICE BULLETIN
BS4848ER1
CAUTION
Before removing, dismantling or maintaining any electrical component, the electrician should take the
necessary precautions to avoid any risk of personal injury or damage to the equipment.
1.5.
Open the rear engine door.
1.6.
Open the belt guard.
1.7.
Locate the power cables and the junction bus bar (see figure 3).
Location of the Corroded
Junction Bus Bar
Figure 3 - Rear View of Engine Compartment
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NQF772001 VERSION 3
SERVICE BULLETIN
BS4848ER1
REMOVAL OF THE ENGINE BOX
NOTE
Make sure to disconnect the ground cable from the structure or batteries and ensure that the ground cable
lug is isolated (see figure 4).
Disconnect the super capacitor control connector and ensure 0V voltage at the bus bar near the engine box
(see figure 5).
Figure 4 - Ground Cable Disconnected and Isolated
Figure 5 - View of the Super Capacitor Control Connector to Disconnect
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NQF772001 VERSION 3
SERVICE BULLETIN
BS4848ER1
1.8.
Remove the 2 upper M6 nuts that hold the engine box to the mounting bracket (see figure 6).
1.9.
Remove the 2 lower M6 nuts that hold the engine box to the mounting bracket (see figure 6).
Lower Nuts
Upper Nuts
Figure 6 - View of Upper and Lower M6 Nuts
NOTE
The Metri-Pack connector is retained and secured with a bolt.
1.10.
Carefully remove the engine box from the mounting studs and then disconnect the two connectors at the
back (see figure 7).
Back Connectors
Figure 7 - Engine Box Removal
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NQF772001 VERSION 3
SERVICE BULLETIN
BS4848ER1
REMOVAL OF THE POWER CABLE LUGS
1.11.
Remove and retain the junction bus bar plastic cap.
1.12.
Remove and retain the nuts that hold the 3 power cable lugs on the junction bus bar (see figure 8).
1.13.
Remove the lowest cable to have a better access to the other 2 upper power cables.
1.14.
Once the lowest cable is removed, pull as far as you can the lugs of the 2 upper power cables that are still
on the junction bus bar.
Remove
Figure 8 - Junction Bus Bar and Power Cables
NOTE
If one of the power cables and/or the junction bus bar has been damaged or is severely corroded (beyond
any possible cleaning or repair), then replace it by using the corresponding Level 2 BOM replacement parts.
Otherwise, continue with the following steps of the procedure.
PAGE 7 OF 12
NQF772001 VERSION 3
SERVICE BULLETIN
BS4848ER1
CLEANING OF THE CABLES AND JUNCTION BUS BAR
CAUTION
Apply the recommended personal precautions (e.g. adequate ventilation) and wear Personal Protective
Equipment (PPE) such as chemical splash goggles and neoprene gloves, as specified in each product Safety
Data Sheet (SDS).
1.15.
Using the CRC Citrus Degreaser remove the dirt (see figure 9) and the grease from both sides of each power
cable lug, from the junction bus bar and from the hardware nuts.
1.16.
Using a nylon bristle brush and the CRC QD Contact Cleaner product, remove the corrosion (see figures 9
& 10) from both sides of each power cable lug, from the junction bus bar and from the hardware nuts.
Dirt Accumulation
Corrosion
Figure 9 - Junction Bus Bar and Power Cable Lug
Figure 10 - Corrosion Cleaning Brush and Contact Cleaner Product
1.17.
Once all the parts are cleaned, reinstall the 3 power cables on the junction bus bar with the nuts and torque
to 21.5Nm (do not apply yellow torque seal at this point).
1.18.
Remove the black plastic cap from the fuse holder located to the right of the engine box removed earlier
(see figure 11).
1.19.
Remove and retain the nuts of the power cable lugs and of the 250A fuse.
1.20.
Remove the 250A fuse to clean it.
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NQF772001 VERSION 3
SERVICE BULLETIN
BS4848ER1
1.21.
Using the same degreaser and corrosion cleaning products specified earlier, repeat steps 1.15 and 1.16 to
clean fuse holder power cables lugs and fuse holder metal contact parts.
1.22.
Once all parts are clean and dry reinstall the 250A fuse and the power cables with the nuts and apply a
torque of 20Nm.
Plastic Cap
Figure 11 - Fuse Holder Black Plastic Cap
APPLICATION OF THE DOLPH ER-44 PRODUCT
NOTE
Ensure that you allow 10 minutes for each coat to dry before applying the next coat.
1.23.
Apply 3 thin coats of the Dolph ER-44 product over the exposed metal surfaces of the junction bus bar, power
cable lugs, fuse terminals, fuse holder terminals and nuts (see figure 12).
1.24.
After the last Dolph ER-44 coat has dried, apply the yellow torque seal on each nut. Then, reinstall the
protective plastic caps over the junction bus bar and the fuse holder.
Figure 12 - Dolph ER-44 and Yellow Torque Seal Applied
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NQF772001 VERSION 3
SERVICE BULLETIN
BS4848ER1
REINSTALLATION OF THE ENGINE BOX
NOTE
Ensure that the Metri-Pack connector is retained and secured with the bolt.
1.25.
Screw the Metri-Pack connector middle bolt until the plastic clips on both sides of the connector are correctly
positioned. Torque to 7Nm and apply yellow torque seal.
1.26.
Reinstall the engine box after reconnecting the two connectors at the back.
1.27.
Tighten three of the four M6 nuts while retaining the fourth M6 nut holding the upper left corner for later
assembly, to complete the deflector bracket installation.
NOTE
Ensure that the first three M6 nuts are properly secured (no torque specified).
INSTALLATION OF THE DEFLECTOR BRACKET
1.28.
Remove and discard the p-clamp lock nut holding the lower power cable (see figure 13).
Lock Nuts
PN N44887
Figure 13 - View of Power Cables and Junction Bus Bar
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NQF772001 VERSION 3
SERVICE BULLETIN
1.29.
BS4848ER1
Install the new deflector bracket PN N100476 on existing studs (see figure 14).
Deflector Bracket
PN N100476
Cable Tie
PN N57807
Figure 14 - Installation of the Deflector Bracket
1.30.
Adjust the deflector bracket to avoid any electrical contact with the junction bus bar and power cable lugs
exposed metal surfaces connected to the 24V alternator power distribution.
1.31.
Install lock nuts PN N44887 on the engine box and p-clamp studs and torque to 14.5±1 Nm (see figure 13).
1.32.
Install the cable tie mount PN N57807 on the deflector bracket hole in order to secure the alternator cable
(see figure 14).
1.33.
Reconnect the batteries ground cable and the super capacitor control connector.
1.34.
Set the battery disconnect switch in the battery compartment to the ON position.
1.35.
The vehicle may be returned to service. 
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NQF772001 VERSION 3
SERVICE BULLETIN
BS4848ER1
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NQF772001 VERSION 3