Immersion Heater Circuit

[NewbieRuffy]

I have a plumber mate who is installing an (3Kw I believe) Immersion heater into a property and needs it wired in. I know in an ideal world, i new circuit from the CU, 16A CB and 20A FCU, as we all know the world is not always ideal and getting a new circuit from the CU to the airing cupboard upstairs is not at all going to be easy as the customer doesn't want walls chased out floors taken up and so on. So, as I am still gaining experience and this is my first immersion connection can i spur off the RFC on upstairs sockets? I have checked the Reg's and cant find anything that says i cant, however anything over 2KW usually needs its own circuit though right? there isn't much load on the upstairs RFC, couple of TV's, laptop now and again, general stuff. Your thoughts please?

 

[sedgy34]

So Sedgy a 3kw portable load is different current wise to a fixed 3kw watt load .........................must have missed that part out in my ohms law theory

no its not but the immersion will draw current for longer periods, if you take your assessor to a job and you have spured of the ring for the immersion im sure you will have a long debate about its design and end up with a re visit.

 

[i=p/u]

There is no right or wrong so sing a little song. But I'd tap of upstairs ring and maybe put on a boost timer. Upstairs ring probably 30A , but isit poster , yeah yeah yeah do pp diddle le op

 

[sedgy34]

better still find the leg coming from the board and redirect it to the immersion make the ring a radial "simples"

RING V RADIAL THREAD LOL

 

[malcolmsanford]

Is it now..................

My argument as never been it's design or it's merit.

My argument as been that we seem to have a consensus on here that a 3kw load is going to trip a 13amp BS 1362 cartridge fuse because it is under designed for the load.

I have sited that manufacturers of equipment be it portable or fixed deem it satisfactory to fit BS 1363 plug tops to their equipment with 13amp fuses.

According to you lads that is wrong, the 3kw load is to great for it and therefore they have this wrong.

Now regardless of what you or others feel, that what is or is not a good design, I have conceded that it is not the best, I have conceded that I would want the system on a 16amp dedicated circuit connected via a 20amp double switch, that as never been argued.

What I'am arguing is why will this 3kw load fuse a 13amp cartridge fuse under normal use?

 

[sedgy34]

malc i know depends on demand

 

[Geordie Spark]

Is it now..................

My argument as never been it's design or it's merit.

My argument as been that we seem to have a consensus on here that a 3kw load is going to trip a 13amp BS 1362 cartridge fuse because it is under designed for the load.

I have sited that manufacturers of equipment be it portable or fixed deem it satisfactory to fit BS 1363 plug tops to their equipment with 13amp fuses.

According to you lads that is wrong, the 3kw load is to great for it and therefore they have this wrong.

Now regardless of what you or others feel, that what is or is not a good design, I have conceded that it is not the best, I have conceded that I would want the system on a 16amp dedicated circuit connected via a 20amp double switch, that as never been argued.

What I'am arguing is why will this 3kw load fuse a 13amp cartridge fuse under normal use?

I'm not sure if this little anecdote has much - if anything - to do with this discussion, but the winter before last, a small boy took a 3kw fan heater into the shed where he was playing and forgot to switch it off after he's finished.

That 3kw fan heater ran for three whole days and would have probably run for a few days more had we not wondered why the shed roof was the only thing not covered with snow!!!

 

[malcolmsanford]

Honestly Sedgy mate I understand what your saying about the design part, and I agree.

But the physics behind this I will still maintain. Rightly as you say an immersion is going to be under load more often that a kettle, and even a fan heater.

But the Burco Urns in my opinion would be very similar, in fact I would imagine in most cases a tea urn would be under more load than an immersion, and they are on plug tops with a 13amp fuse

A 13amp cartridge fuse will not trip with a 3KW load in normal operating circumstances it is that simple

 

[sedgy34]

Honestly Sedgy mate I understand what your saying about the design part, and I agree.

But the physics behind this I will still maintain. Rightly as you say an immersion is going to be under load more often that a kettle, and even a fan heater.

But the Burco Urns in my opinion would be very similar, in fact I would imagine in most cases a tea urn would be under more load than an immersion, and they are on plug tops with a 13amp fuse

A 13amp cartridge fuse will not trip with a 3KW load in normal operating circumstances it is that simple

i think its one for the amendments as the old immersions were 16amp the new immersions are a switched fuse connection unit

 

[Sparkystu79]

My immersion is connected via a fcu and its yet to blow in 6 years of constant use.

 

[malcolmsanford]

To quote the whole paragraph from P56 electrician's guide to the building regs

"Immersion heaters should be supplied through a switched flex-outlet connection unit (to BS1363-4) or a double pole switch with flex outlet complying with BS EN60669-1 or BS EN 60669-2-4"

Now you lads know that i'm not a great lover of these "one size fits all" guides, but here is one that I agree with

 

[sedgy34]

To quote the whole paragraph from P56 electrician's guide to the building regs

"Immersion heaters should be supplied through a switched flex-outlet connection unit (to BS1363-4) or a double pole switch with flex outlet complying with BS EN60669-1 or BS EN 60669-2-4"

Now you lads know that i'm not a great lover of these "one size fits all" guides, but here is one that I agree with

yes but the circuit doesnt say if its spured off the ring or on its own circuit does it

 

[Engineer54]

Honestly Sedgy mate I understand what your saying about the design part, and I agree.

But the physics behind this I will still maintain. Rightly as you say an immersion is going to be under load more often that a kettle, and even a fan heater.

But the Burco Urns in my opinion would be very similar, in fact I would imagine in most cases a tea urn would be under more load than an immersion, and they are on plug tops with a 13amp fuse

A 13amp cartridge fuse will not trip with a 3KW load in normal operating circumstances it is that simple

Give up Malcolm, as they say, you can take the horse to water but..... lol!!

Same with the other thread on RCD's for IT sockets in an office wired in metal conduit!!

 

[Knobhead]

Tony shakes head in despair. There’s no bloody wonder Joe can afford his pint.

Electrician: I’m allowed to safely spur off of your existing wiring but I think I’ll rip ½ your house to bits so that I feel better. Oh, and the price will be £---
Joe: I’ll just put in a couple connecters under the floor near by. It won’t cause any mess missus. The price will be £XX.

Look at it how ever you like!

 

[Rockingit]

better still find the leg coming from the board and redirect it to the immersion make the ring a radial "simples"

RING V RADIAL THREAD LOL

Sorry mate, but have you been on the pop today?! Just because, your argument seems to be with continuous current draw, yet your solution here is to effectively downgrade the circuit by 12A. Can I have one of whatever you're on?

 

[Engineer54]

Sorry mate, but have you been on the pop today?! Just because, your argument seems to be with continuous current draw, yet your solution here is to effectively downgrade the circuit by 12A. Can I have one of whatever you're on?

Well, ...he does live in a light bulb, bless him!! lol!!!