Maybe another daft electrical question

[dcocks]

In our shed we have a raidial main with 13 amp sockets connected one to another no cable back to the consumer unit like a ring main.
The cable is 4mm
The MBC is a 32a type B
As i need a 16 amp supply can i just change one of the 13amp sockets for a 16 amp blue one or run a new spur of the main cable????? or do i need a sparky
All ideas greatly receaved
Thanks in advance David

 

[Welderpaul]

Strictly speaking - yes you need a qualified sparky - he is best placed to advise and make sure your installation is safe.
I would suggest that he links the last socket back to the consumer unit to form a ring main (I.e the sockets can be fed with juice from two directions - lowering the load on the cable)
Normally 4mm cable is reserved for heating/higher load applications - normally 2.5mm for 13A sockets. - Installation sounds all a bit DIY-ish
I..er...someone...has in the past just swapped a 13A domestic socket for a 16A socket with no probs. I would suggest tho that you install a dedicated spur (Or ring if you want a couple) to your 16A socket. Bear in mind that 16A plugs do not contain a fuse - so your MCB needs to be correctly rated - too high a rating and it won't trip to protect you (Unless a direct fault), too low and it will just keep tripping.
PS I'm a welder not an electrician so......

 

[dcocks]

Well it was done by a pro sparky before we moved there is even got the company name on the consumer unit. I will admit that it does look a bit diy ish apart from the 3 phase that looks pretty good to me.
think i will give them a call tomorrow see if they are still on the go
anyway thanks for your reply David

 

[Welderpaul]

Well it was done by a pro sparky before we moved there is even got the company name on the consumer unit. I will admit that it does look a bit diy ish apart from the 3 phase that looks pretty good to me.
think i will give them a call tomorrow see if they are still on the go
anyway thanks for your reply David

Better a larger cable than small tho. Have seen socket ring mains wired in 1.5mm (lighting cable)!

 

[piman]

Hello David,

the cable is the right size for the breaker unless you have a very long run from the shed to the supply?

How many sockets do you have connected on this circuit, and how many appliances would you operate at the same time?

There is nothing wrong with a radial circuit, and I don't see any problem of replacing a 13A with a 16A socket. Certainly, there is not the same protection for the appliance you plug into the 16A socket as you get with the fuse protected 13 plug.

Alec

 

[HasBean]

Gents,
I have a 4mm radial supply to my garage from a 20A mcb in the consumer unit. I have fitted a consumer unit in the garage so I can isolate the two 13A outlets and 16A socket I've fitted. The only other outlet on this supply is a socket powering a 5W clock so effectively I have the whole supply to myself!
Is it possible/safe to change the 20A mcb for a 30A one? (old type consumer unit). All the cabling I've used is 4mm as well. The cable length is about 20m max and runs under the floorboards.


Paul

 

[piman]

Hello Paul,

Yes, that will be ok, you will not overload your supply cable. As I mentioned , appliance is more at risk as the protection will be 30 amps but I would imagine that most appliances will have an internal fuse? If you wanted maximum protection for whatever you run at 16A, then fit a dedicated circuit breaker in an enclosure and connect the 16A socket to that.

I.e., between the 4mm cable and the 16A socket outlet.

Alec

 

[HasBean]

Thanks Alec,
At least that gives me scope for a bigger mig now