New Consumer Unit

[mickl66]

Just had electrician fit me a new CU, during the fitting he informed me that second ring main has no continuity on the live side so he has fitted a 16amp mcb rather than a 32amp on this ring. I have since looked at this myself, taking all the face plates off and making sure that there's no loose or trapped wires on the insulation and all okay, I then checked the lives at the CU for continuity and all okay phase showing 0.05 ohms resistence.
I then connected phase 1 to neutral 2 and phase 2 to neutral 1 and checked the readings on each socket outlet on that ring, all gave a reading of 0.07, so i'm assuming no bridge across this ring.
Is there anything I have missed or as the electrician made a mistake.
Many thanks.

 

[lxboy]

Hi, you may have had a loose connection which you have rectified when checking the sockets. I would tell the electrician you found a loose connection in a socket and ask him to check again.

Regards,

ixboy

 

[EFLImpudence]

The measurements are not what would be expected from a correct ring circuit.

They are impossibly low.

 

[DetlefSchmitz]

Maybe the leads weren't zeroed.

 

[EFLImpudence]

They still don't make sense.

The first reading should be half of the second.

That would mean -
leads 0.03 and each conductor 0.02.

Were the meter still zeroed for longer leads than those being used the readings are even more unlikely.

 

[DetlefSchmitz]

Probably worth asking which test instrument was being used. OP?

 

[riveralt]

Just had electrician fit me a new CU, during the fitting he informed me that second ring main has no continuity on the live side so he has fitted a 16amp mcb rather than a 32amp on this ring.

Didn't think you could have a ring final less than 20A.
I cannot understand why the electrician left you in this situation.
If he fitted the new CU then he should have conducted the appropriate tests before he started the installation and informed you of his findings before going ahead and fitting the new CU.
At lot of what you are saying doesn't make sense - What does it say on the electrical installation certificate - how can he inform your LA building control - get him back to sort out the problem.

 

[lxboy]

Just had electrician fit me a new CU, during the fitting he informed me that second ring main has no continuity on the live side so he has fitted a 16amp mcb rather than a 32amp on this ring.

Didn't think you could have a ring final less than 20A. It wasn't a ring when he left ? He fitted a 16a to make he installation safe to use, and yes, he could have used a 20A but may not have had one in the van.

Lxboy

 

[riveralt]

Just had electrician fit me a new CU, during the fitting he informed me that second ring main has no continuity on the live side so he has fitted a 16amp mcb rather than a 32amp on this ring.

Didn't think you could have a ring final less than 20A.

It wasn't a ring when he left ? He fitted a 16a to make he installation safe to use, and yes, he could have used a 20A but may not have had one in the van.

I do wish you would learn how to use the system.

The OP seems to think he has a ring - since he is apparently doing end to end continuity testing (and not getting an open circuit) and figure of eight testing (again no open circuit).

 

[undistilled]

Sounds to me like the electrician did the appropriate tests and find a lack of continuity on at least one leg of the ring and took appropriate action in the circumstances. I assume the client (OP) was aware that problems might be found and if so extra work might be necessary. In this case he was notified of the problem; the installation was left safe and the client has the option of leaving as is or paying the electrician to spend the time hunting down the cause of the fault and rectifying as appropriate. I assume the client was also advised that it might be beneficial to have an EICR carried out prior to any electrical work being done but chose not to. So, riveralt, looks like the electrician did sort out the problem and left the installation safer than it was before he started the works.[/i]

 

[lxboy]

The electrician said no ring

Kindest regards,

lxboy

 

[Iggifer]

The electrician said no ring

doesnt mean he was right

 

[mickl66]

Sorry everybody,

Should have mention that I'm using a digital multi meter set to continuity (200ohms) there's no zero function so I checked resistance of the leads which reads 0.04, I deducted this from the first reading which gives the reading of 0.05 but forgot to do the same with the second reading so this should be 0.03. not sure i'm doing the right thing but let me no what you think.

Regards Mick.

 

[Spark123]

It doesn't sound right, 2.5mm copper at 20°C has a resistance of 7.41m&#937;/m hence if your 0.05&#937; figure is correct then your ring circuit is <7 metres long.

 

[davelx]

That type of multimeter is generally very inaccurate when measuring single low resistances. You really need to use a proper low reading meter or continuity tester.