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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> open circuit https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1101337340 Message started by spongebob on Nov 24^th, 2004, 11:02pm

Title: open circuit
Post by spongebob on Nov 24^th, 2004, 11:02pm

What is meant by the term open circuit? How would I test for such a thing?

Title: Re: open circuit
Post by HandyMac on Nov 25^th, 2004, 12:30am

When a light switch is switched off it is an open circuit, the light bulb doesn't have its power flowing so it doesn't light up.

The test is - does the bulb light up.

Andrew

Title: Re: open circuit
Post by spongebob on Nov 25^th, 2004, 12:34am

ooooooohhhh.....sounds technical! Time to call someone in!

Title: Re: open circuit
Post by Stoday on Nov 25^th, 2004, 12:35am

It just means that there is a break in the circuit so that no current can flow through the load. A switch may be open or a fault could cause a conductor to break. Or (in the case of a ring main) the ring may be incomplete so that current flows through only one arm of the ring.

But watch out! An open circuit is not necessarily dead and you could get a shock. An open circuit is not the same as an isolated circuit, which has all conductors disconnected from the power source.