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Home / Technical Articles / 10 Important Precautions When Working On Low Voltage Energized Equipment

Have eyes in the back of head…

For most work, the electrical equipment must be de-energized because there is a high risk of injury to workers if they work on energized equipment. It may be possible to schedule such work outside of normal work hours to limit the inconvenience.

Sometimes it is not practicable to completely disconnect low-voltage equipment before working on it.

10 Important Precautions When Working On Low Voltage Energized Equipment
10 Important Precautions When Working On Low Voltage Energized Equipment (photo credit:

For example, it may be necessary to have equipment running in order to test it or fine-tune it. In such cases, the work must be performed by workers who are qualified and authorized to do the work. They must follow written safe work procedures.

You should observe the following important precautions when working on energized equipment, but note that these are not a substitute for proper training and written safe work procedures:

1. Think ahead

Assess all of the risks associated with the task. Plan the whole job in advance so that you can take every precaution, including arranging for help in case of paralyzing shock. Consider the use of a pre-job safety meeting to discuss the job with all workers before starting the work.

2. Know the system

Accurate, up-to-date information should be available to those who work on the system. This means that you should know all equipment installed according to the valid documentation (technical specifications, single line diagrams, wiring diagrams, block schemes etc.).

Be careful, sometimes equipment stated in documentation can differ from the one installed on site – due to the replacing of old (damaged) equipment with the new with similar characteristics.

3. Limit the exposure

Have live parts exposed for as little time as necessary. This does not mean that you should work hastily. Be organized so that the job can be done efficiently.

4. Cover exposed live metal

Use insulating barriers or shields to cover live parts. Plexiglas plates can be usefull.

5. Cover grounded metalwork

Grounded metal parts should be covered with insulating material as much as possible. Very important.

6. Limit the energy to reduce the risk

All practical steps should be taken to ensure that the fault current at the point of work is kept as low as possible while the work is in progress. For example, when measuring voltage, do it on the load side of the circuit-protective devices with the smallest current rating.

Current-limiting devices can be used to reduce the risk of an arc flash.

7. Remove metal stuff

These could cause a short-circuit where small clearances are involved. (If it is necessary to wear medic-alert bracelets, secure them with transparent surgical or adhesive tape or rubber bands.)

8. One hand, face and body to side

Use one hand with your face and body turned to the side when operating a safety switch. Limit possible injuries by not placing body parts directly in front of energized equipment when there is danger of an arc flash.

9. When you’re in awkward positions…

Avoid electrical contact when working in awkward positions. If you must work in an awkward or unbalanced position and reach with your tools, use insulating cover-up material on the tools to avoid contact with live conductors.

10. Equipment and clothing

Use the correct safety equipment and clothing. Remeber: gloves, clothes and shoes.

Safety clothes, gloves and shoes
Safety clothes, gloves and shoes

Reference: Electical Safety at Low Voltage –

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Edvard Csanyi

Electrical engineer, programmer and founder of EEP. Highly specialized for design of LV/MV switchgears and LV high power busbar trunking (<6300A) in power substations, commercial buildings and industry facilities. Professional in AutoCAD programming.


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    Mar 17, 2015

    The following article considers The Neccessity Of Lock Out Tag Out (LOTO), Arc Flash & Occupational Safety in the workplace.

    FREE Safety Training Video : Why Lock-Out, Tag-Out Is Vitally Important By Panduit – See more at:

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    Why Lock-Out, Tag-Out Is Vitally Important….. watch this 15 minute video covering LOTO Electrical Safety produced by Panduit. This 15-minute video is a training video on OSHA 1910.147, the Control of Hazardous Energy.

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