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

Multimeter

Multimeters are undoubtedly the most common item of electrical test equipment in use.  Often it is the first piece of equipment people will turn to when...

Closed Doors

"I can live with doubt and uncertainty and not knowing. I think it is much more interesting to live not knowing than to have answers that might be wrong...

LED Replacement Light Bulb

The inventor of the first visible light-emitting diode makes history again this year as it begins to show customers a 40-watt replacement GE Energy Smart...

Low Voltage Circuit Breakers

Circuit breakers are switching devices whose primary function is to isolate parts of an electrical distribution system in the even of abnormal conditions...

8 Motor parts and common faults

Straight forward list of some common motor faults.  If I have missed any other common faults, please take a bit of time to add them in as a comment below...

Variable Frequency Drive

Variable frequency drives are widely used to control the speed of ac motors.  This note looks at the mechanisms which enable drive units to control the...

IEC 61439 Verification Methods

The (relatively new) switchgear and control gear standard, IEC 61439 'Low-voltage switchgear and controlgear assemblies' has three methods which can be...

How to refer fault levels across a transformer

Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary...

What happened to the cable notes?

If you are wondering what happened to our cable notes, the short answer is that we have moved them to myCableEngineering.com.  The "Knowledge Base" at...

Introduction to Current Transformers

Current transformers (CTs) are used to convert high level currents to a smaller more reasonable level for use as inputs to protection relays and metering...

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