Discuss RCD's and storage heaters in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

R

rasell

Are there any known issues with RCD's and storage heaters?

I've done an inspection on my own house, the storage heaters are on their own board, its a TNCS system. The only problem is that when they were installed the wires were tucked under the joists rather than through a hole in the middle. So I did not think they had adequate mechanical protection.
However as the electicity only comes on in the night its unlikely that someone would be drilling holes then.
How do people do an installation cert. when there is no power? I can't imagine people coming back in the middle of the night!

I was thinking of protecting the board with a 30mA RCD to meet the regs and for extra safety. Are there any likely problems with nuisance tripping?

Regards

Marc
 
Nothing wrong with the install provided it met the regs when fitted...my house is all chiseled joists, as is every other house in this estate that was built at the same time. Just because this doesnt meet current regs doesnt mean its wrong. It should be marked as a "4" on the PIR. For your own peace of mind you could fit RCD protection, as this deficiency is also a "4" on the PIR if you don't have an RCD board. Nuisance trips are usually the fridge or fridge/freezer, and it is common practice to run the supply to this without RCD to prevent such trips.
 
Nothing wrong with the install provided it met the regs when fitted...my house is all chiseled joists, as is every other house in this estate that was built at the same time. Just because this doesnt meet current regs doesnt mean its wrong. It should be marked as a "4" on the PIR. For your own peace of mind you could fit RCD protection, as this deficiency is also a "4" on the PIR if you don't have an RCD board. Nuisance trips are usually the fridge or fridge/freezer, and it is common practice to run the supply to this without RCD to prevent such trips.

Thanks for the reply, when did it become a requirement to have mechanical protection?
Even if its not required I like to have things as safe as possible in my house.

I forget to mention that the meter tails are 16mm2 so I'm assuming I will have to upgrade them to 25mm2.

Regards

Marc
 
Meter tails are the responsibility of the electricity supplier...If you want them changed you'll have to contact them direct. The consumer tails (i.e from the Suppliers Isolation to your CU) are yours, yet there is little point in upgrading them if the supply is insufficient. Check with your supplier first
 
That's an interesting question - how do people do an installation cert for a board and or circuit when there is no power there at the time due to it being supplied by "off peak" energy, I have tested storage heaters to find a fault by temporarily connecting the circuit to a spare way in the "normal" board for the property with chocblock and an extra piece of t+e to extend it - this is the only way I can think of to produce "live" test readings such as Zs and RCD testing (if RCD protected off peak board).....without coming back in the middle of the night.
 
As Stixcus has said, when testing Eco 7 boards, or fault finding, I normally jump across boards.
 
Fitting an rcd to storage heaters seems alien to me. I looked at a board change today and figure that to comply i will need to rcd the heaters.
 
According to regs, you are allowed to have an item supplied independent of an RCD provided it is socket fed and specifically labelled for that item of equipment. (reg 411.3.3 if you're interested)
As night storage heaters are not usually socket fed, but are "fixed equipment" I am pretty sure the regs about RCD protection do not apply.
Anyone got any other ideas???
 
The only reason I can see to RCD heaters, would the depth of cables etc, same reason as smoke alarms.
 
That's an interesting question - how do people do an installation cert for a board and or circuit when there is no power there at the time due to it being supplied by "off peak" energy, I have tested storage heaters to find a fault by temporarily connecting the circuit to a spare way in the "normal" board for the property with chocblock and an extra piece of t+e to extend it - this is the only way I can think of to produce "live" test readings such as Zs and RCD testing (if RCD protected off peak board).....without coming back in the middle of the night.

older type have a small slider switch in the teleswitch,which you can flick to give you power at any time but I think you might have to break the seal to get at it. oh no!
 
I,ve had a few faulty rcd,s recently so testing that without power would be a prob. Would make sense to link out to perm live side i suppose.

This job just gets more complicated don,t you think. Would never have thoght we would be rcd,ing storage heaters, cookers ,lighting and immersion heaters (assuming they are flush wired)

So many things seem open to interpretation. I will have a few questions when my Niceic inspection comes up soon.

Ian
 
You only need to RCD the heaters if it is a new install. There is no requirement in 17th ed to upgrade an existing install to provide an RCD, unless you want to that is. A CU upgrade will require an RCD in this case, as you state the cables are shallow and unprotected, and as such require the additional protection.
(See OSG 3.6.1)
 
It is a small studio flat, has 5 on peak circuits and 2 off peak. I am going to try and get it all in 1 enclosure.
Way i see it, i will have a main switch isolating 2 rcd,s and 5 mcb,s then another rcd isolating 2 mcb,s for the off peak. What a lot of switches to explain!!

Ian
 
It is a small studio flat, has 5 on peak circuits and 2 off peak. I am going to try and get it all in 1 enclosure.
Way i see it, i will have a main switch isolating 2 rcd,s and 5 mcb,s then another rcd isolating 2 mcb,s for the off peak. What a lot of switches to explain!!

Ian
Your off peak supply should be on its own board.as it will need to be supplied with separate tails,but you can use your 30ma as the main switch.Do you not also have an off peak immersion heater?
 
I was going to use it as a dual tariff board-on and of peak. Actually there is only 1 heater and an immersion.

Ian

Aha,I've never come accross one of them,sorry I was thinking of econemy7 type of installation where the supply authority allow you to connect storage heaters and waterheating only I think.
 

Reply to RCD's and storage heaters in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock