INSTRUCTION TO SERVICE
ITS: 59024
SECTION:

260

BATTERY COMPARTMENT

WRITTEN BY:

Curtis Matthews

SUBJECT:

MSD replacement – SR-2178, 2179, 2250

ITS59024

THIS DOCUMENT AND THE CONTENTS DISCUSSED HEREIN ARE THE CONFIDENTIAL AND
PROPRIETARY INFORMATION OF NEW FLYER INDUSTRIES CANADA ULC AND NEW FLYER OF
AMERICA INC. AND ARE DISCLOSED BY NEW FLYER IN CONFIDENCE. THIS DOCUMENT AND THE
CONTENTS HEREIN ARE NOT TO BE DISCLOSED BY THE INTENDED RECIPIENT WITHOUT THE PRIOR
WRITTEN AUTHORIZATION OF NEW FLYER. ANY UNAUTHOIZED DISCLOSURE, REPRODUCTION OR
OTHER DISTRIBUTION OF THIS DOCUMENT OR INFORMATION IS STRICTLY PROHIBITED AND MAY
RESULT IN ACTION BEING TAKEN AGAINST THE PARTY MAKING THE UNAUTHORIZED DISCLOSURE.
THIS DOCUMENT AND ALL COPIES HEREOF MUST BE RETURNED TO NEW FLYER UPON REQUEST.

WARNING:

Only trained personnel shall supervise and perform High Voltage system testing,
checkout and troubleshooting. Two personnel (one called the Checker & the other
called Monitor/Recorder) shall perform Checkout Procedures, together, to ensure
safety of themselves, others nearby & for the protection of vehicle & property.
Refresher training shall be provided to these personnel on a regular basis and
when new systems are to be checked by them. The training of the personnel shall
consist of:

1.0 SAFETY PROCEDURE: (Mandatory for all SRs)



1.1

Fill out and submit a Live Work Permit to the shop lead. See Appendix C for a Live Work Permit.

1.2

Turn the master run switch to the off position and wait 5 minutes before proceeding.

1.3

Turn the 12/24V battery disconnect and HV Interlock switch to the “OFF” position.

1.4

Lock and Tag the electrical system of the bus out and retain the key. See Figure 1.

1.5

Install a Lockout/Tagout Steering wheel cover as require

NOTE:

Refer to the Lockout/Tagout Procedure in section 1 of your Preventive Maintenance
Manual or section 9 of your Service manual for additional information.



NOTE:

Use commercially available lock out equipment and tags being sure to follow any local
laws or workplace procedures.



NOTE:

Refer to New Flyer High Voltage Safety Guidelines and Procedures Document 532295
(Appendix A) when completing installation or service work on high voltage power cables.

Figure 1: Lockout tagout location reference

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WARNING:

High Voltage PPE Category 2 is required. Please refer to Appendix B or the safety
section of your Preventive Maintenance Manual and Service Manual for more
information. There shall be no communication from observers with the 2 personnel
performing HV work. If required all work must stop until communication has been
completed.

1.6

Review the scope of work to be completed with the Monitor/Recorder.

1.7

Review/Rehearse the actions required in case of any possible accident scenarios.

1.8

Using an appropriate voltmeter as per appendix A, confirm that no voltage is present between
HVPOS_VEH_FB & HVNEG_VEH_FB before proceeding. See Figure 2. These connections are located
inside the HV Fuse box inside the inverter rack. See Figure 3 layout for location.

Figure 2: High voltage fuse box location reference

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1.9

Identify the location(s) of the ESS compartments that will require work. See Figure 3. (Refer to your
wiring schematic or schematics often located on the underside of the ESS enclosure lids)

ESS ABOVE CENTER
WHEELHOUSE

Figure 3: Battery pack string location reference
1.10 Ensure the bus is not charging and gain access to the roof of the bus ESS enclosures and the other
applicable ESS enclosure(s). Ensure the appropriate fall protection PPE is used and appropriate
safety procedures are followed when applicable.
1.11 Determine and organize the required tools neatly before work begins.
1.12 Before removing any MSD(s), confirm voltage is present between the positive in terminal on the
BDU and negative in terminal on the BDU. See Figure 5.

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1.13 Confirm that NO voltage is present between the positive out terminal on the BDU contactor and
negative out terminal on the BDU contactor. See Figure 4.

Figure 4: BDU and contactor location reference

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2.0 Retrofit Procedure
2.1

Locate the rooftop ESS and open ESS battery panel. See figure 5.

Open ESS
battery panel

Figure 5: Rooftop ESS
2.2

Locate MSDs x2. See figure 6.

MSDs x2

Figure 6: Rooftop ESS MSD location

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2.3

Remove and discard MSD plugs x2. Remove and keep high voltage barrier and mounting hardware
x4. See figure 7.

Remove and keep high
voltage barrier and
mounting hardware x4
Remove MSD
plugs x2
Figure 7: Rooftop ESS MSDs and HV barrier
2.4

Remove and discard MSD brackets x2. See figure 8.
2.4.1

Unfasten and keep bracket mounting hardware from rooftop ESS frame x8 bolts +
washers + nuts.

2.4.2

Unfasten and keep MSD receptacle mounting hardware x8 bolts + washers. Also,
unfasten MSD stud nuts x4 that clamp down on HV busbars.

Remove and
discard
brackets x2

Remove and keep
bracket mounting
hardware x8

Remove and keep
MSD receptacles
mounting hardware x8

Figure 8: Rooftop ESS MSD receptacles and busbars exposed

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2.5

Remove MSD receptacles and busbars. See figure 9.
2.5.1

Remove and keep powerbar boots x4 to expose busbar hardware, remove and keep
busbar hardware x4.

2.5.2

Remove and keep stud nuts x4 connecting busbars to MSD receptacles.

2.5.3

Remove and discard MSD receptacles x2 and busbars x4.

Remove and discard
MSD receptacles x2,
keep stud nuts x4

Discard busbars x4

Remove and keep
hardware x4 and HV
powerbar boot x4

Figure 9: Rooftop ESS MSD receptacles and busbars exposed
2.6

Bench assemble new rooftop ESS MSD assemblies. See figure 10.
2.6.1

Using original MSD mounting hardware x8, bench assemble MSD receptacle PN:
(806450) x2 and plug PN: (805480) x2 onto bracket PN: (855541) x2.

2.6.2

Torque all MSD mounting hardware bolts x8 to 14 ft-lbs (DRY).

MSD receptacle
PN: 806450 and
plug PN: 805480
x2

MSD bracket
PN: 852861
Fasten original MSD
mounting hardware x8,
torque to 14 ft-lbs (DRY)
Figure 10: Rooftop ESS MSD bench assembly

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2.7

Install new MSD bench assembly onto bus. See figure 11.
2.7.1

Fasten HV busbars PN: (852894) x4 and current sensing harness to new MSD
receptacle PN: (806450) studs with nuts x4 kept from step 2.5, torque nuts to 80 in-lbs
(DRY).

2.7.2

Fasten rear ESS bench assembly to rooftop ESS frame with the bracket mounting
hardware x8 kept from step 2.4. Torque all hardware to 14 ft-lbs (DRY).

Fasten HV busbar
mounting hardware
x4 to 14 ft-lbs DRY
and attach original
HV busbar boot x4

Fasten bracket
mounting
hardware x8 to
14 ft-lbs DRY

Fasten HV busbars
and current sensing
harness to new
MSD studs with
original nuts x4 to
14 ft-lbs DRY

Figure 11: Rooftop ESS MSD bench assembly
2.8

Re-install rooftop ESS high voltage barrier removed in step 2.3.

2.9

Remove all tools and debris and return the bus to service condition.

2.10 Remove all locks and tags from battery disconnect switches and steering wheel.