Notes

How to Check a Circuit is Dead 

By on

If you want to check a circuit is dead (not live), you should always use the three point method.  First check a known live circuit, then check the dead circuit and finally recheck the live circuit.  Carrying out the procedure ensures that the meter is working before and after testing for the dead circuit.

A few additional measurement tips to make things safe:

  • always connected ground or negative clips first (remove last)
  • hang or rest the test meter (try not to hold in your hand)
  • use PPE - see our PPE Post

 If anyone has other tips to share, please add in the comments below.

, ,

More interesting Notes:
Steven McFadyen's avatar Steven McFadyen

Steven has over twenty five years experience working on some of the largest construction projects. He has a deep technical understanding of electrical engineering and is keen to share this knowledge. About the author

myElectrical Engineering

comments powered by Disqus

Bows and Arrows

It starts with me reading one of the Horrible History books with my son (Groovy Greeks). Arrows were mentioned which lead to the discussion of the bodkin...

Fault Calculation - Symmetrical Components

For unbalance conditions the calculation of fault currents is more complex. One method of dealing with this is symmetrical components. Using symmetrical...

Tips for a better Low Voltage Protection Discrimination Study

Carrying out a protection system discrimination study is critical to ensure the correct functioning of  the electrical system in the event of faults. ...

How to Write an Electrical Note

Electrical notes are a collaborative collection of electrical engineering information and educational material. Any registered user can add content. ...

Low Voltage Fault Tables

The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.

Maximum Demand for Buildings

Estimating maximum demand is a topic frequently discussed. Working out how much power to allow for a building can be very subjective . Allowing too much...

IEC 61439 - The Switchgear Standard

The new standard IEC 61439 replaces the old 60439. Compared to the old standard, the new 61439 is a more clearly defined and takes into account the assembly...

Gas Insulated or Air Insulated Switchgear

Various arguments exist around SF6 Gas Insulated (GIS) and Air Insulated (AIS) medium voltage switchgear. Recently we had to change a GIS design to AI...

Power Factor

Power factor is the ratio between the real power (P in kW) and apparent power (S in kVA) drawn by an electrical load. The reactive power (Q in kVAr)...

What does N+1 mean?

The term 'N+1' relates to redundancy and simply means that if you required 'N' items of equipment for something to work, you would have one additional...

Have some knowledge to share

If you have some expert knowledge or experience, why not consider sharing this with our community.  

By writing an electrical note, you will be educating our users and at the same time promoting your expertise within the engineering community.

To get started and understand our policy, you can read our How to Write an Electrical Note. 

Footer
(click here to extend)
Copyright (c) 2026 myElectrical