Isolate and re-energise high voltage systems in an electric vehicle

URN: IMIEV04
Business Sectors (Suites): Electric and Hybrid Vehicles,Maintenance and Repair - Light Vehicle,Maintenance and Repair - Heavy Goods and Public Service Vehicles
Developed by: IMI
Approved on: 31 Dec 2020

Overview

This standard is about assessing an electric vehicle and isolating it to make it safe to work on. It also covers re-energising the vehicle once the required work has been carried out.

For the purposes of this standard, an electric vehicle is any vehicle that is in part or wholly electrically propelled. This would include:

  • Hybrid (HEV) - to include mild/micro hybrid vehicles where the voltage is considered dangerous.
  • Plug-in Hybrid (PHEV)
  • Extended Range Electric Vehicle (ER-EV) or Range Extended Electric Vehicle (RE-EV)
  • Battery Electric Vehicle (BEV) or Pure Electric Vehicle (PEV)
  • Fuel Cell Electric Vehicle (FCEV).   


Warning: It has been recommended by industry experts that only those with suitable training and experience on working with electric vehicles should carry out the functions below.


Performance criteria

You must be able to:

P1 Locate relevant information about the vehicle and use it to determine any potential hazards
P2 Identify any potential hazards by carrying out a dynamic risk assessment of the vehicle
P3 Identify high voltage components and cabling
P4 Notify relevant colleagues of your intention to work on a high voltage vehicle
P5 Select and use correct personal protective equipment when isolating and re-energising the high voltage system
P6 Ensure the work area is clearly identified and made safe 
P7 Follow the manufacturer's procedures to isolate and re-energise the high voltage system
P8 Work in a way which minimises the risk of:

P8.1 injury to yourself and others
P8.2 damage to your working environment
P8.3 damage to other vehicle systems, components and units
P9 Prepare, check and use all the appropriate test equipment following manufacturer's instructions
P10 Follow the manufacturer's recommendations to ensure residual voltage is within manufacturer's specification when isolating the high voltage system
P11 Use suitable testing methods to evaluate the performance of the re-energised high voltage system accurately, ensuring that it performs to the manufacturer’s operating specifications and legal requirements
P12 Refer any problems with the process to a relevant person in your workplace
P13 Ensure records are accurate, complete and passed to the relevant person(s) promptly in the format required.


Knowledge and Understanding

You need to know and understand:

Use of technical information
K1 The different types of electric vehicle and their electrical systems
K2 The terminology used within electric vehicle systems
K3 How to find, interpret and use sources of information applicable to isolating and re-energising an electric vehicle’s high voltage systems
K4 The importance of knowing how and where to access relevant information on the specific electric vehicle systems
K5 How to determine the location and route of the high voltage components and cabling
K6 Specific high voltage vehicle safety systems relevant to your work

Legislative and organisational requirements and procedures *
K7 The current health and safety legislation, industry codes of practice or guidelines and specific vehicle manufacturer's repair and safety procedures relevant to working with electric *vehicles
K8 The hazards associated with working with electric vehicles and how to identify them
K9 How to select and use appropriate and correct personal protective equipment
K10 How to work in a way which minimises the risk of:

K10.1 injury to yourself and others
K10.2 damage to your working environment
K10.3 damage to other vehicle systems, components and units
K11 The implications of electrical conductivity through the human body 
K12 The implications of strong magnetic fields and the effects on medical devices 
K13 Workplace procedures that must be followed in the event of electric shock or other emergencies
K14 Your workplace procedures for the referral/reporting of problems when working with electric vehicles
K15 How to make others aware that work is being carried out on electric vehicles
K16 The specific manufacturer’s guidelines and the precautions necessary when charging, connecting an auxiliary power source to or towing/lifting an electric vehicle
K17 The hazards associated with electric vehicles when exposed to extreme temperatures, impact and other adverse conditions


Use of testing equipment *
K18 How to select and use the correct electrical testing equipment required
K19 How to calibrate and test equipment prior to use

Isolating and re-energising vehicle high voltage systems
K20 How to isolate and re-energise an electric vehicle’s high voltage system following manufacturer’s instructions
K21 How to accurately test that the residual voltage is below manufacturer’s specification following the isolation process
K22 How to interpret test results and make recommendations based on these results and the importance of basing recommendations on test results
K23 How to test and evaluate the performance of the system against manufacturer's operating specifications and legal requirements
K24 The importance of ensuring all high voltage vehicle systems are functioning correctly and safely before the *vehicle is released to the customer


Scope/range

1. Vehicle - any vehicle that is in part or wholly electrically propelled. This would include
1.1. Hybrid (HEV) - to include mild/micro hybrid vehicles where the voltage is considered dangerous.
1.2. Plug-in Hybrid (PHEV)
1.3. Extended Range Electric Vehicle (ER-EV) or Range Extended Electric Vehicle (RE-EV)
1.4. Battery Electric Vehicle (BEV) or Pure Electric Vehicle (PEV)
1.5. Fuel Cell Electric Vehicle (FCEV)

2. Testing methods include:
2.1. sensory
2.2. functional
2.3. measurement

3. Components include:
3.1. batteries/stack, pod, module
3.2. motors
3.3. cables


Scope Performance


Scope Knowledge


Values


Behaviours


Skills


Glossary

This section contains examples and explanations of some of the terms used but does not form part of the standard.

Dynamic risk assessment - the practice of mentally observing, assessing and analysing an environment while working, to identify and remove risk. The process allows individuals to identify a hazard on the spot and make quick decisions in regards to their own safety.

Hazards associated with high voltage electrical vehicle components - exist not only during work on high voltage systems, as specified above, but also on all other high-power electrical drive systems and high-pressure storage systems. Vehicle and equipment manufacturers’ guidance should be followed at all times.

High voltage – Regulation No 100 of the Economic Commission for Europe of the United Nations (UNECE) — Uniform provisions concerning the approval of vehicles with regard to specific requirements for the electric power train, states that: ‘High Voltage’ means the classification of an electric component or circuit, if its working voltage is > 60 V and ≤ 1 500 V DC or > 30 V and ≤ 1 000 V AC root mean square (rms). Electricity at Work Regulations (1989), and associated HSE guidance should be followed at all times.

Sensory testing methods include looking, listening, smelling, touching for temperature or vibration.

Sources of information applicable to electric vehicles 
Examples include hard copy manuals, data on computer and data obtained from on- board diagnostic displays.


Links To Other NOS


External Links


Version Number

3

Indicative Review Date

31 Dec 2023

Validity

Current

Status

Original

Originating Organisation

IMI Ltd

Original URN

IMIEV4

Relevant Occupations

Auto-electrical Technician (Automotive), Automotive Aftermarket Electrical Enhancement Technician (Automotive), Heavy Vehicle Diagnostic Technician (Automotive), Heavy Vehicle Fleet/Service Manager (Automotive), Heavy Vehicle Master Technician (Automotive), Heavy Vehicle Service Technician (Automotive), Heavy Vehicle Trailer Diagnostic Technician (Automotive), Heavy Vehicle Trailer Fleet/Service Manager (Automotive), Heavy Vehicle Trailer Master Technician (Automotive), Heavy Vehicle Trailer Service Technician (Automotive), Light Vehicle Diagnostic Technician (Automotive), Light Vehicle Fleet/Service Manager (Automotive), Light Vehicle Master Technician (Automotive), Light Vehicle Service Technician (Automotive), Mechanical, Electrical and Trim Assistant Technician (Automotive), Mechanical, Electrical and Trim Technician (Automotive), Bus and Coach Mechanic, Bus and Coach Electrician, Bus and Coach Mechelec, Bus and Coach Master Technician, Coachbuilder

SOC Code

5231

Keywords

Electric vehicle: high voltage; isolate; re-energise