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

Frame Leakage Protection

While not as popular as it once was, frame leakage protection does still have some use in some circumstances.  In essence frame leakage is an earth fault...

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...

Power Transformers - An Introduction

One of the fundamental requirements of an alternating current distribution systems it to have the ability to change the magnitude of voltages.  It is more...

How to measure power supply quality

If your are ever called out to troubleshoot something on your electrical system, one of the first things consider is the supply voltage. You want to ensure...

How to Size Power Cable Duct

Some colleagues had an issue earlier in the week on sizing conduits to be cast in concrete for some power cables . It became clear that none of us had...

How a Digital Substation Works

Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using...

Introduction to Lighting

When looking at the design of a lighting scheme it is useful to have an understanding on the nature of light itself and some of the basic theory associated...

Equipment Verification (to IEC Standards)

One of the requirements to ensuring that everything works is to have equipment selected, manufactured and verified [tested] to IEC standards. Not all equipment...

Battery Cars A to Z

Battery powered cars are a hot topic and widely debated. The pros, cons, issues and time frames can be talked about endlessly. An article by the Telegraph...

Railway Electrification Voltages

This post is quick introduction and overview to different railway electrification voltages used in answer to a question sent in via email. While there...

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) 2025 myElectrical