avoiding overload (need a little advice)

[peterdevlin1]

Right heres the deal! I have a main consumer unit rated at 80Amps, I recently had an extension done and had a sub main fuse board put in which is rated at 63Amps and supplied with a 10mm armourded cable with. A run of about 25 meters. I notied today that the MCB supplying the submains board is only rated at 32A, this is fine right now because all thats running off the sub mains board is 1 10A lighting circuit and 2 rings but the plan was to add in an electric hob and and 2 electric ovens... Is there any way of changing the size of MCB supplying the submains board without overloading the main board! And of course without creating a safety issue

 

[Andy™]

best call a sparky who will be able to tell you what can be done

 

[Evans Electric]

Depending on the Installation Method of the 10mm you could go to 60A .

How is the 10mm cable run .

1) Clipped to the buiding?

2) Buried in the ground?

3) Run on a metal cable tray ?

Someone didn't tell someone else all the facts by the sound of it .

Well yes as Andy says , a Sparky needs to assess the new load , do a calc . and do the neccessary.

 

[Andy™]

Depending on the Installation Method of the 10mm you could go to 60A .

for the cable yes, but for all we know he has an old wylex with plug in MCB's, which are only designed for a max of 32a per way

also, 60A on 10mm over 25mtr may give VD issues

 

[peterdevlin1]

Its a fairly new hager board, and the cable is clipped to the ouutside of the building but then disappears under the house, id say the biggest run is just lying under the house

 

[Andy™]

quick check with TLC shows your probably OK for upto 50A, 63a will give you VD problems

of course, this assumes that every circuit at the other end has almost no length (/R1R2)

 

[Technician]

Would it not be prudent to apply the

diversity calculations to show that

no problems might be caused upstream?

 

[SPECIAL LOCATION]

this is fine right now because all thats running off the sub mains board is 1 10A lighting circuit and 2 rings but the plan was to add in an electric hob and and 2 electric ovens... Is there any way of changing the size of MCB supplying the submains board without overloading the main board! And of course without creating a safety issue

Give us a clue about what power rating these ovens and hob are......??? :C

otherwise..

you may as well go and ask the lady on the checkout at Tesco's if it will be alright!!!

What is the existing load on the property at the moment?

Not what rating is the main switch in the CU..

Need far more details to be able to offer any significant advice...

 

[betty swollocks]

Just a thought but why not ring spark who did work for extension and put your new supply/board in

I'm sure he could give you the answers you want as he would know all the facts

I'm assuming the extension was notified and you have received certificates for all the previous work?

If not, why not?