Page 247 - CTS - Mechanic Diesel - TP

MECHANIC DIESEL - CITS

EXERCISE 14.6: Depowering the High voltage system in

Electric vehicle

Objectives
At the end of this exercise you shall be able to
• isolate the high voltage system in Electric and Hybrid vehicles before any service

Requirements

Tools/Instruments Equipment/Machines
• EV insulated hand tools kit - 1 Set • A light motor electric vehicle - 1 No.
• Stanchion with retractable belt - as reqd. Materials
• Multi meter - 1 No.
• Waste cloth - as reqd.
• 1000 V“0 class” hand rubber gloves - 1 Set
• Lockout take off box (LOTO BOX) - 1 No.
• Glove powder - as reqd.

Procedure

1 Park the electric vehicle in plain surface and cover the vehicle parked area using stanchion to avoid the
unwanted people entry.
2 Unlock doors, tail and bonnet

3 Turn off the ignition key
4 Put Ignition key in lockout take off box (LOTO box) and keep it 5 Metre away from the vehicle.
5 Remove the vehicle rear seat back to gain access to the high voltage battery module
6 Check the hand gloves for any cut or damage, ensure its standard, date of last inspection then wear it after
applying the glove powder. Strap on the hand gloves

Note: Remove the Golden rings, bangles before wearing the gloves
7 Disconnect the 12V battery Negative cable and Low voltage fuse plug.

8 Remove the switch lid from the IPU cover on the battery module
9 Remove the locking cover and turn the battery module switch off and then reinstall the locking cover in its
position to secure the switch is in off position

10 If no switch is provided, remove high voltage service plug and place it LOTO box
11 Wait for ten minutes to allow the ultra capacitors to discharge.
12 Locate the terminals for the junction board
13 Measure the voltage at terminals and verify the voltage is Zero or less than 30V. If the voltage is more than
30 V there is a problem, after rectifying the problem then only any service can be done

Note: The above general procedure for shutting off high voltage systems should only be used
if instructions from the actual manufacturer are not available otherwise follow strictly the
Manufacturers isolation procedure only. During the service insulated hand tools only must be used.

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