socket testing

[philipb]

Hi Guys,
A customer rang today,he had his washing machine looked at by
a local company,the motor brushes were the problem but the engineer
did a test on the socket that feeds the washing machine and said it
had a reading of 100 ohms on it.He said the cooker socket was the same.
He advised not to use the washing machine until it was repaired.
The elderly gent said he used a box with a row off lights on and no display
to test the sockets.I put my fluke 1551 on and tested the loop and got .81 ohms.
all the other sockets were .2 to .6 ohms,the fuseboard is and old wylex fuse wire type.
The old gent was a bit put out by this,and worried.Its not the first time i have had this.
philipb.

 

[Jabbajaws]

Hi philipb. Is it a radial circuit that you are checking or a ring final circuit?

 

[philipb]

Hi jabajaws,its a radial single cable taken from the house ring.

 

[Jabbajaws]

So we are talking about a spur, which has been fed from a ring circuit? Just trying to be clear here phililpb.

 

[philipb]

Yes its a spur,just a bit concerned how a service engineer for washing machines,
with a box can condem a socket with a so called 100ohm reading on it when in
fact it has 0.8ohms on it.what is the box he was using?any ideas?

 

[topquark]

Yes its a spur,just a bit concerned how a service engineer for washing machines,
with a box can condem a socket with a so called 100ohm reading on it when in
fact it has 0.8ohms on it.what is the box he was using?any ideas?

Persil?

 

[Submains]

LMFAO.
All time classic answer there topquark.
Still chuckling now with a vision of a Persil box and test leads.

 

[pushrod]

Yes its a spur,just a bit concerned how a service engineer for washing machines,
with a box can condem a socket with a so called 100ohm reading on it when in
fact it has 0.8ohms on it.what is the box he was using?any ideas?

Probs something like THIS Personally i would put my faith in a more conventional tester like your own rather than some wonder toy that attempts to do everything

 

[MarkieSparkie]

Sounds like the service engineer used a socket tester with earth loop test. I have a Martindale E-Ze Check Extra and it often gives indications >10 Ohms on final circuits that I have already tested in the normal way with an MFT and know to be <1 Ohm in reality. Socket testers are useful secondary checks but I would not rely on one as a primary test method, no matter how sophisticated the manufacturer claims it to be. As well as unreliable loop tests, I've yet to test one that can reliably show N-E reversal.

For further advise/information see ECS Best Practice Guide 8, link below:
http://www.esc.org.uk/fileadmin/user_upload/documents/industry/best_practice/BPG8_10.pdf

 

[truckster]

At the end of the day you are the pro sparks, the other bloke has a noddy tester and a days training, Comet engineers for example don't know a TT system from their elbow. I have had a few call from people who have been told they cant have their cooker/freezer/wash machine fitted because their earthing is dangerous i.e. more than 1ohm.

 

[telectrix]

just looked at that toy. appears the " accurate mains voltage measurement" is anywhere between 207 - 253v, fantastic accuracy there! what?

 

[RWJ]

I've also got the martindale.....
It only ever says 0Ω - 1.7Ω on anything...
Again even if the megger says other wise

I've stopped using it now... and will probably return it to the person I...... borrowed it from

 

[Marvo]

If you've done all the appropriate tests on the socket in question and there's no problems evident I would just fill out a test sheet with the test results, give the customer a copy and that's that. If the customer still has a problem then he should contact the washing machine guy for his test results in writing so you can compare and figure out why there's a discrepancy.

 

[philipb]

Thanks for your comments guys,the company was indesit,they did leave a results sheet,
showing over 100ohms on two sockets.there are some contact details which i will follow up.