safe to convert a fused switched circuit to a wall socket?

[alex2012]

Hi,
There is an aborted 5A (or maybe 3A for it is originally used for a boiler) switched fused circuit in my kitchen. The circuit is directly from the junction-box.
Since all the wall plug sockets in the kitchen are on the other side of wall, I am thinking of adding a new wall socket in the kitchen to connect a fridge or a microwave around 800 watt or a toaster aroubd 1200w by change the aborted circuit to a wall socket. I am wandering if it is safe to do so or whether it will tip off the circuit in juntion-box when new appliance other than the orginal boiler is plugged into this socket. I noticed the wire radius in aborted circuit is a bit smaller than other wire used in 30A ring circuit.

 

[PrenticeBoyofDerry]

Do you intend to remove the fused connection unit (FCU) and replace that with socket or do you intend to run additional socket from the FCU?
You state that the FCU is taken from a 30A ring final circuit and the FCU has been taken directly from that via junction box. Has the FCU only got one set of cables to it on the supply side (ignoring the load cables of the boiler)
Do you have any idea what CSA (size) this cable is?
I assume but could you confirm that you have no RCD protection on the circuit. As you will require RCD protection for any additional work you do to this circuit, if it is not present.
You do have options:
You could convert the FCU to a socket outlet (RCD protected).
You could change the FCU to a RCD protected 13A fused connection and then run a number of sockets to the load side. You will be restricted to 13A maximum load though (2.99kW)
But conformation of circuit design and cable size would be required.
Also make yourself aware of legal requirements of notification for electrical work within kitchens. //www.diynot.com/wiki/electrics:part_p

 

[sparkwright]

Do you intend to remove the fused connection unit (FCU) and replace that with socket or do you intend to run additional socket from the FCU?
You state that the FCU is taken from a 30A ring final circuit and the FCU has been taken directly from that via junction box.

I'm not sure he does say that. He says the FCU is supplied from the junction box in cable smaller than the 30 amp ring. Could this 'junction box' in fact be the consumer unit?

We need to know what size fuse or circuit breaker serves the FCU, and some clarification on that cable size.

 

[PrenticeBoyofDerry]

I stand corrected.
So we need to know where the spur/FCU is taken from.
Whether this is from the RFC or whether this is from another circuit, it could be possible that the FCU is taken from the lighting circuit to supply the boiler, so in that case you will not be able to use for a 13A socket outlets.
Clarification is required.
Could you please identify the circuit and circuit type, including fuse rating, this FCU is being supplied from? and is there any RCD protection in place?

 

[alex2012]

Thanks for all guys.
The FCU is from juntionbox, the consumer unit. I added a photo of the junction box. The second circuit from right is the one orginally and only used for the boiler with a label of 5A. The circuit is aborted now. I would like to convert this circuit to a wall socket to plug a fridge or microwave (800 w) or a toster (1100-1300w) by replacing the FCU.
I noticed the radius of wire on FCU end of this circuit is smaller than other wires in the wall socket (30A) in the kitchen, not sure the size exactly.

 

[Iggifer]

You would need to keep the FCU, put a 5 amp fuse in it and take the socket off there.

But I wouldn't recommend doing that, I would get an electrician in to do the work, especially as it's in a kitchen

 

[Iggifer]

View media item 44785

 

[alex2012]

Thanks for Iggifer's comment and loading the photo for me.

The FCU circuit once had a broken neutral and aborted. I managed to find the broken neutral under floor board. The former electrican only sticked the two wires loosely together with a type, even not bother to twist the two wires to be fishing hook like.
Since this circuit is aborted now, I am wondering whether it is safe to reuse it by converting to a wall socket. The lable in the junction box seems to be 5A.

(The boiler is connected to another circuit from the junction box (the first one from the left). The circuit (orginally 30A) was once used in an aborted workshop in the front shed by a former house ower. I spotted the live with a non-contact voltage detector. The cable just goes nearby the boiler. I then cut the cable and converted it to a FCU (3A) to be used by the boiler. )

View media item 44785

 

[Iggifer]

you cannot simply convert it to a wall socket because:

5a fuse = 5 amps
13 a wall socket = 13 amps

If you swap like for like, you WILL overload the circuit and blow the fuse.

The reason the electrician did not twist the wires together is that you should NEVER twist solid core conductors together. Only tri-rated cables (such as flex) are suitable for twisting. Twisting damages the conductors

 

[alex2012]

I see. Anyway I connected the two open neutrals with a wire connector now. However it is abandoned since the boiler is connected to another FCU circuit.

If this abandoned circuit needs to be converted to a wall socket of 13A how an electrician will do the job? Will he add RCD to the junction box as PrenticeBoyofDerry suggested or replace the cable with bigger CSA size all the way from junctionbox? Thanks

you cannot simply convert it to a wall socket because:

5a fuse = 5 amps
13 a wall socket = 13 amps

If you swap like for like, you WILL overload the circuit and blow the fuse.

The reason the electrician did not twist the wires together is that you should NEVER twist solid core conductors together. Only tri-rated cables (such as flex) are suitable for twisting. Twisting damages the conductors

 

[Iggifer]

An electrician would need to add a little shower unit with a an RCD and MCB in it such as:

Dependant on the size/age of the cable he may also need to replace.

Your best bet is to get a spark in and quote you for the work

 

[Chri5]

The fused spur is fused as a direct circuit on the cu as 5 amp. You can replace the spur with a socket provided you are ok with the limits of the 5amp fuse at the cu.

5 x 230v gives a load of 1150w. The cable will be either 1.0mm or 1.5mm te, which means the board fuse could be changed to 10 amp.

Would it not be easier to take a direct spur from the existing 32amp ring?

 

[alex2012]

Thanks. There is similar device next to the junction box for the shower circuit. The house was built around 1970s.

An electrician would need to add a little shower unit with a an RCD and MCB in it such as:

Dependant on the size/age of the cable he may also need to replace.

Your best bet is to get a spark in and quote you for the work

 

[alex2012]

Thanks.
Do you mean there is fuse in the consumer unit for this circuit which could be changed to 10A to allow other powerful applicance if the cable's size is 1.5MM? I don't see any fuse on the consumer unit however. I will measure the cable's size later. I guess the power of my fridge is around 400-600W. Should I simply replace the fuse in the plug lead of any applicance which I may plug into this new socket to 5A for safe use?

There are only two wall socket outlets on the other side wall in the kitchen. I don't like cable runs everywhere if I take a direct spur from the existing 32amp ring. To reuse the abandoned circuit seems good for me, however the lable in the consumer unit is only 5A and the cable's size is a bit smaller than others in 30A ring circuit.

The fused spur is fused as a direct circuit on the cu as 5 amp. You can replace the spur with a socket provided you are ok with the limits of the 5amp fuse at the cu.

5 x 230v gives a load of 1150w. The cable will be either 1.0mm or 1.5mm te, which means the board fuse could be changed to 10 amp.

Would it not be easier to take a direct spur from the existing 32amp ring?

 

[EFLImpudence]

Consumer Unit - CU

Junction Box