15Amp immersion plug

[Deleted member 9648]

That reg would be a bit ambiguous to me. I'd class a standard domestic tube element as being insulated, it is earthed after all. An uninsulated element to me would mean an electrode type boiler where AC power isapplied directly to the immersed plates and the load current actually flows through the water being heated but I've never seen these in a domestic application, only in industrial steam generators. If the reg refers to an electrode heater though why doesn't it refer to them by name?

Yes,there was a debate a while back on this very subject,not everyone agreed that the reg applied to electrode type elements,which personally I have never come across.But at the time I argued that the reg did not apply to normal domestic elements which are insulated as you rightly state. Still seems to me the most likely reason(reg) why the inspector has applied a code 2,mistakenly IMO.

 

[Flanders]

just to add, and in general, if you are required to do remedial work to sort out problems after an EICR and you don't agree with the codes, what paperwork can you provide to the customer to verify that the installation is safe?and even when you do agree with the codes and remedy the faults, what paperwork do you provide?

You can fill out an Electrical installation certificate if you have a lot of deviations to rectify, you only need to test and inspect the circuits you have work on, just fill out N/A in the parts of the report not applicable and on the front page were you are ask to enter the extent of the installation cover in this report write for example "remedial work to rectify items 1,2,3 and 4 of EICR 12345678" or if there there is only a couple of deviations then minor work certs would be OK , If you are not working or altering any circuits for example securing a loose accessory then you could just identify the remedial work you have done on the invoice to the customer and reference it to the EICR number and observation number.
If you disagree with a coding identified you could also put this in writing to the customer or although sometimes it easier to rectify the deviation rather than trying to explain why in you view that its OK and does not require and remedial action .

15 amp sockets are commonly used on lighting rigs in theatres and my Nan's house god rest her sole

 

[Marvo]

Yes,there was a debate a while back on this very subject,not everyone agreed that the reg applied to electrode type elements,which personally I have never come across.But at the time I argued that the reg did not apply to normal domestic elements which are insulated as you rightly state. Still seems to me the most likely reason(reg) why the inspector has applied a code 2,mistakenly IMO.

I didn't see any previous debate on this but it doesn't surprise me it causes confusion with the way it's worded. I might be missing something obvious but I still don't understand the reason the different types of elements might exclude the option of havnig it on a plug though.

 

[spark 68]

Hi Marvo,
here is the page from the regs, sorry for the poor scan, it may make a bit more sense from reading the preceding regs.

 

[HandySparks]

...and my Nan's house god rest her sole

Unusual type of pet to keep, but each to their own. :smiley2:

 

[Marvo]

Hi Marvo,
here is the page from the regs, sorry for the poor scan, it may make a bit more sense from reading the preceding regs.

Thanks Spark, appreciated.

The attached page does answer a couple of the things that didn't make sense to me but it also raises some new questions.

It makes a definite distinction between electrode water heaters, heaters with an uninsulated element and therefore by default heaters with an insulated element. I understand electrode heaters, and I assume astandard mica filled element is an insulated element so...what is the uninsulated element that's referred to?

554.1.4 Could make for some very interesting RCD requirements It also refers to a connection which is 'exceeding low voltage' which I assume means >1000VAC. I didn't realise that 7671 covered medium and high voltage supplies.

554.1.7 Goes into remarkably complex detail about the actual construction of the appliance. Firstly I get the impression this is unusual for BS7671 which is general installation regs and secondly how would you go about finding this information as a standard installation electrician?

Apologies in advance if I'm misunderstanding something but I'm not familiar with the UK regs.

 

[moospark]

Unusual type of pet to keep, but each to their own. :smiley2:

cue the dead parrot,

 

[westmac]

I'm doing nothing of the sort, the fact is, you're all applying 230V criteria to a power system that has a nominal voltage of 240 volts!! As i said earlier, 230volts is all make believe ...or a fairly tale if you like!! lol!!

My disagreement isn't with the fact that 230v is rare, it's with the fact that you think the power rating of a heating element is constant. Going back to your earlier calculations in which you reasoned that a higher voltage would result in a lower current, they are wrong. An increased voltage across a fixed resistance will always result in an increased current.

 

[BroadReach]

were there ever electrode boilers made with metal (conductive) boling vessels?!? I am interested here.

All of the electrode boiles I come across use plastic, usually polyprop, boiling vessels.

There is mention of connecting both Neutral & Earth to boiler casing, this implies a conducive casing, or have I mis-understood.

I realise this technology is cheap and tends to get replaced often in industry and I have only been in the industry 15 years, but kit I see is often 30 years old, never seen a metal cased boiling vessel on an electrode boiler.

As a "non electrician" (I am a mechanical engineer but the kit I supply uses lots of that lovely electrickery stuff and I have a genuine interest!) I thought connecting Neutral and earth together (even after the cutout on a PME) was a no-no?

Genuinely interested here.

 

[Marvo]

I'm also genuinely interested in this as well and I've just started doing some homework. Electrode boilers are constructed as metal cased as well as plastic. I can't find a local standard that's applicable (South African SANS) but there's a British Standard BS1894:1952 which refers to riveted seamless and welded electrode boilers.

Don't suppose you have a copy handy by any chance cause I'm not in the mood to part with 140 quid i'm afraid

 

[Engineer54]

My disagreement isn't with the fact that 230v is rare, it's with the fact that you think the power rating of a heating element is constant. Going back to your earlier calculations in which you reasoned that a higher voltage would result in a lower current, they are wrong. An increased voltage across a fixed resistance will always result in an increased current.

I'm not disagreeing with you, on that score, that's the whole point of voltage optimisers when all said and done. But what is the current draw on a 230 volt 3KW heating element then??

 

[shanky887614]

I'm not disagreeing with you, on that score, that's the whole point of voltage optimisers when all said and done. But what is the current draw on a 230 volt 3KW heating element then??

Max of around 13amps

 

[Geoffsd]

That's true but the point being made, I think, is that immersion elements don't come in 3kW @ 230V.

They are stated by the manufacturer as 3kW @ 240V - 12.5A, (19.2Ω which doesn't alter - apart from temperature).
If you blindly use the nominal voltage of 230 without adjusting the power you will get 13A.

Conversely if you do, for design, adjust correctly to the 230V power you have 2.76kW @ 230V = 12A but
the actual voltage will be 240V or more so you are designing for what will rarely happen.

It may be assumed that this was allowed for when the nominal voltage was lowered but who knows?


The above differences are small but for larger appliances the differing results, depending on which way it is done, could lead to under- or over-sized equipment being installed causing danger or unnecessary expense.

Search shower and cooker threads for confirmation.

 

[Engineer54]

I think we are talking at cross purposes here. my main point was using 230 volts for calculation, when we all know full well, it's still 240 volts (nominal) that's being supplied in the UK!!

 

[shanky887614]

I think we are talking at cross purposes here. my main point was using 230 volts for calculation, when we all know full well, it's still 240 volts (nominal) that's being supplied in the UK!!

?

Ive come across 250 and 255 before