Resistance too high

[Mjward]

Puzzling one to me and my sparky isn't available for a week so hoping there might be a simple fix:

The electric oven keeps turning itself off. Oven technicians came out today to fix but said can't do anything as tested the socket and the ohm reading is too high ("over 10 ohms"). Tested other sockets and also all too high (again told "all over 10 ohms).

Now I got an electrical certificate (EIRC) only 5 months ago, nothing flagged and max Zs for these circuits 2 and below.

I guess A) what could have changed in that time and B) is it right to think that solving A could be what is triggering the oven to turn off?

Thanks in advance to any and all replies, I've got a tenant in so keen to solve as quick as I can 

 

[Murdoch]

Hum. Looking at your EICR what is the supply type? TT? TNS? TNCS?

what is the Ze?

What were the ZS readings for the circuit the cooker is on?

What was the ZS reading for the cooker circuit?

if you upload the EICR, please redact the site details and the inspectors details

 

[binky]

testing through sockets isn't reliable and often gives false high readings due to corrosion / dirt on the contacts.

 

[Murdoch]

Hum. Looking at your EICR what is the supply type? TT? TNS? TNCS?

what is the Ze?

What were the ZS readings for the circuit the cooker is on?

What was the ZS reading for the cooker circuit?

if you upload the EICR, please redact the site details and the inspectors details

And whats tripping? MCB? RCD?

 

[Mjward]

Hum. Looking at your EICR what is the supply type? TT? TNS? TNCS?

what is the Ze?

What were the ZS readings for the circuit the cooker is on?

What was the ZS reading for the cooker circuit?

if you upload the EICR, please redact the site details and the inspectors details

TN-S supply

Zs for board was 0.17

Zs for cooker circuit was Max 1.75 and Meas 0.41

Trying to upload the EICR but I can't find the button to add an attachment I'm afraid 

testing through sockets isn't reliable and often gives false high readings due to corrosion / dirt on the contacts.

Was thinking this too but was assured multiple sockets were tested and even behind the socket on one ie at the connection

 

[Mjward]

And whats tripping? MCB? RCD?

This is it, nothing is tripping. The oven just turns up, tenant uses it, then switches itself off i.e. power goes from it completely. Next time the tenant goes to use it, same thing.

Had me thinking it was heat related (i.e. getting to certain temperature and causing something to cut out) but the oven technician (and definitely far more professional than me) is adamant it's nothing to do with the oven and is circuit related.

 

[Murdoch]

Not taking sides here but come tests on the circuit do seem the next logical step - the fact the EICR suggests a Zs of 0.41 and the cooker chap suggests its now over 10 ohms is a good place to start - with somebody with a proper tester

Hope this helps

 

[ProDave]

It might be a bit of a palava, but take the oven to a socket that is on a different circuit, that may be upstairs,. and try it.

That will answer once and for all is it oven or circuit.  If it is the circuit you need an electrician.

 

[Mjward]

 Good advice all..will await the professional to do thorough testing

 

[Mjward]

Sparky managed to come out today and fix.

Just for others who might come across this issue:

1) main earth to street had deteriorated and replaced

2) double pole to oven switch faulty and replaced 

 

[ProDave]

Sparky managed to come out today and fix.

Just for others who might come across this issue:

1) main earth to street had deteriorated and replaced

2) double pole to oven switch faulty and replaced 

thanks for letting us know, sounds like you got a good electrician. Keep his number in a book for next time you have electrical problems.

 

[Mjward]

Agree! He is a top guy