Bizarre voltage readings

[Gossy]

I have installed a new cooker supply to the new DB. The cable is a 10 mm T+E. It's on a 50 amp RCBO. (Big cooker!!) tested the cable and made put it in connector block and switched it on. I was getting 240v down live to earth which is correct but neutral to earth is was getting 40v. Then live to neutral I was getting 118V . I thought it was thought it was the RCBO but changed it three times and still read the same. When I connected it to cooker I get 240 v through neutral and earth as well as live and earth. What's going on???

 

[Plonker 3]

What results did you get for your IR and R1+R2 tests?

 

[telectrix]

think i'd be doing R1+Rn as well.

 

[Deleted member 72666]

I would carry out a R1+Rn test as well. Why did you change the rcbo 3 times?

EDIT: Tel beat me to it!

 

[snowhead]

I'd be looking at the links in the terminal block in the cooker.

 

[telectrix]

i'd also query the use of 10mm cable and 50A MCB.

 

[Engineer54]

i'd also query the use of 10mm cable and 50A MCB.

Yep, must be a bloody ''BIG'' cooker to need a 50A breaker....

 

[nickblake]

there is something amiss with a neutral connection there some where like has been said r1 rn should be carried out

 

[Octopus]

Certainly go back to your dead tests and confirm the continuity of all 3 conductors.

 

[UNG]

More of a bizarre post than voltage readings

 

[londonlec]

What results did you get for your IR and R1+R2 tests?

What will this prove?

 

[Octopus]

What will this prove?

If it's been tested? Just a guess. Lots of bang tests on herehere

 

[jay sean]

Check the connection of the earth and neutral cables

 

[richy3333]

Why did you change the rcbo 3 times

It's simpler than thinking about the problem and doing some tests!?

 

[trev]

So if you'd had 173 RCBOs would you have gone through them all?

 

[Biff61]

Hi Guys, between N+E the max voltage should be at max 2V, so this sounds very much like a broken neutral somewhere or a badly connected neutral at the CU. my first test would be to check this out. I have this as a common problem here in Africa, especially when we have to use auto transfer switches between the mains incomer and the standby generator and the contacts become pitted and carbonized. So turn off each circuit at the CU, then test for a V between N+E, if it has stabilized and you are getting the correct readings turn on each circuit one by one until you identify the circuit that is giving you the problem.
Hope this helps.