Spur from immersion heater socket

[psarinuk]

Hi

I've recently installed a shower pump in the airing cupboard next to the hot water cylinder and need to feed power to it.
There is no spare power supply or socket in the vicinity, so I was thinking of using a spur from the immersion heater socket.
The spur is going to run a double 3 pin socket to run the shower pump (via 3 pin plug) and occassional vaccum cleaner through the other 3 pin socket).

When I opened the face plate of immersion heater, I found that there are 3 red and 3 black cables at the back side. Does this mean that its already feeding a spur? If yes, I don't see that spur.

What would be the best way? Should I put a junction box in the gray cable that is running to the immersion heater socket and make a spur from this junction box?


Is this allowed/ OK or do you have any better suggestions?
Also if someone has any helpful information/ links to posts on here or elsewhere, it would be great if they can share that.

Thanks for your help in advance..

P.S. I will post a pic tomorrow of the socket in question..

 

[Taylortwocities]

You must find out where those other cables go.

HINT: Turn the immersion contact breaker off at the consumer unit and see what has stopped working!

If the cb size is 16amp then it may not be able to cope with the extra loads, unless you know what they are.

Strictly speaking, heated water vessels in excess of 15litres should have a dedicated supply.

Personally I take a conservative view that immersions are radial circuits, so it should not be a problem sharing the 16amps available with the odd shower pump or intruder alarm provided it is designed properly.

 

[kai]

If the circuit is rated at 16amps or even 20amps - its perfectly safe to run both a 3kW immersion and a 3amp small load off the circuit (No diversity needed here), provided all the earth bonding etc are up to date and installed properly.

 

[psarinuk]

Hi again,

Thanks for your support first of all and sorry for the late reply (hospital visits lately)

I managed to find out that:
1. Immersion heater is on ring main (30Amp), not radial.
2. When disconnected at consumer unit, quite a few sockets stop working in the house.
3. There is a spur supply from immersion heater socket that goes to the timer/ control unit of central heating boiler (hence 3 black and 3 red cables at the back of the immersion heater socket).

Now I need to run the 3amp shower pump which has been installed in close vicinity of immersion heater socket. What are my options here?

P.S. Is there a fused spur with 2 switches for 2 appliances that I can replace it with or is there something like a cooker switch with low amps that can supply a socket and an appliance? (presuming that shower pump can run via 3 pin plug on a socket)?

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[holmslaw]

..

 

[psarinuk]

The immersion heater is rarely used but I get your point.

Should I disconnect the immersion heater for now and get its own dedicated supply from the Consumer unit?

Do they do 2 switch (2 gang) FCUs so I can run the pump and boiler or would you want me to spur the boiler off the pump FCU?

Ideally I would want a 3 pin socket as well in the airing cupboard for the hoover..

 

[holmslaw]

..

 

[psarinuk]

OK I will get the dual box. I've not used them before but I presume the idea is to run the cables from one FCU to another within the dual box and maintain the ring main.

Just to confirm that you want me to connect all 3 in the ring main:
1. 3A FCU for pump
2. 3A FCU for boiler (currently a spur off immersion heater)
The above 2 will be accomodated in a dual box
3. 13A standard double socket will be added to the ring main via 1 junction box

You also want me to run a radial circuit from the consumer unit to the immersion heater and connect the existing 20A FCU socket (pic in previous post) to it. Would standard 2.5mm cable be enough for immersion heater?

Many thanks for your help. Your patience is highly appreciated!

 

[holmslaw]

..

 

[psarinuk]

Yes, I can come off the back instead of junction box but the length of incoming ring main cable might be an issue, hence I might need to use atleast 1 junction box.
Just checked the FCU for the 3KW immesion heater, its only 10A? Is that normal?
Would you still want me to run a radial circuit to immersion heater?

 

[SUNRAY]

Yes, I can come off the back instead of junction box but the length of incoming ring main cable might be an issue, hence I might need to use atleast 1 junction box.
Just checked the FCU for the 3KW immesion heater, its only 10A? Is that normal?
Would you still want me to run a radial circuit to immersion heater?

Replace the 10A FCU, the new one will be 13A

 

[ban-all-sheds]

The immersion heater should be on it's own dedicated circuit, it is too much load for the ring circuit.

Not exactly a hanging offence though.

You can buy 3kW portable fan heaters - they are expected to be plugged in and nobody worries about them being too much load for a ring circuit.
In fact some people don't think that a potential 5kW load on one point of a ring circuit is necessarily unsafe.






psarinuk - you should read this: //www.diynot.com/wiki/electrics:part-p

 

[holmslaw]

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[ban-all-sheds]

Are you saying he should leave it on the ring circuit?

I'm saying that he may do so without being overly concerned about it.

You can buy 3kW portable fan heaters - they are expected to be plugged in and nobody worries about them being too much load for a ring circuit.

Are you saying he should leave it on the ring circuit?

I'm saying that he may do so without being overly concerned about it.

If it's OK, i.e. legal to sell and therefore to use portable 3kW appliances which can only be used by plugging them into one socket outlet, what's the big deal about having a fixed 3kW appliance supplied from one point on a ring?

[In fact some people don't think that a potential 5kW load on one point of a ring circuit is necessarily unsafe.

'some people' , you mean idiots like you.

Untitled

• KKen
• 11 Aug 2010
• 2

A bit of a dogs breakfast, it doesn't comply with regs, but is not necessarily unsafe.

 

[plugwash]

BAS how do you get a "potential 5KW load" from that arrangement? Afaict other than the lights everything in the garage is going through a 16A MCB.