I've recently put a new 10.5kw shower in and upgraded the mcb to a 50amp one. I realise that I need to put an RCD in but have little idea how. I am in no way a sparky and this is in fact my first dabble with the consumer unit so would be grateful if anyone could please help in novice terms!
How to put in a RCD?
- Thread starter no1geezer
- Start date
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geezer, do you have an MCB style consumer unit (fuse board)? If so, the next question is do you have any spare ways (unsused fuses or balnked of sections) If so isolate the power to the board by switching of the consumer unit. Then remove the unsed fuse(s) or blanking plates so that you have enough room to put the RCB in. The fuses and RCDs are held onto a metal busbar by a single screw that when undo you can then unhinge the fuse off the busbar. Put the RCD in in the same manner and screw down. then strip back the end of your cable (the live one that feeds your shower) and connect that into your RCD. Connect the neutral to the neutral block in the corresponding number hole to the fuse (does that make sense?) and also connect the earth to the earth block. If you are working on an old cartridge or rewireable fusebox, you can buy the adaptors to allow the RCD to sit in. These are available from a decent electrical stockist.
I hope this helps. Let me know if you need more help as I am a qualified sparks.
I hope this helps. Let me know if you need more help as I am a qualified sparks.
It is providing that the diyer isolates the power to the consumer unit. Once the power is off, then it should be safe. If the diyer has access to a multimeter or avo, it wouldnt hurt to verify that there is no supply to the busbar that I mentioned in the previous post.
As always if you are uncomfortable with it or in doubt, get a qualified person to do it.
As always if you are uncomfortable with it or in doubt, get a qualified person to do it.
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Can I ask what size cable you have going to your 10.5kW shower? It's not quite as easy as just screwing an RCD onto the bus-bar of the fuse board. You can buy a protective device that will screw straight onto the bus bar; it's called an RCBO(not all board manufacturers manufacture them and they can be pricey). If you tried to screw an RCD onto the bus bar you would have trouble, apart from the fact that doing away with your MCB and connecting it instead to an RCD would provide no protection to the cable from overload or fault currents. The neutral connection decribed would also give you trouble; if you're going to connect a live cable to the load side of an RCD, you must also ensure that the neutral conductor is connected to the load side of the RCD. If you connect it into the neutral bar (supply side) as described, you will find that the RCD will not even switch on. I would go for a stand alone 63amp RCD (30mA trip) in an enclosure. I hope I didn't read your post incorrectly filthy, but there's a bit more to it than just putting an RCD onto the busbar. With regard to live parts in the consumer unit masona, you will find that the supply terminals to the main switch are live all the time so you should exercise caution as these terminals are usually only protected by the suppliers fuse.
B
breezer
for what its worth I agree with spark you cant just put in a bigger shower and just change the mcb (it may not be safe) as for the rcd, it is going to cost a small fortune for a standalone version, and as for the consumers unit, as you are asking i would say don't touch it.
Again spark is right, the incoming side is still live and extra care should be taken.
Personally i would buy a bigger split load consumers unit and get an electrician to fit it for you.
electricity has no prejudices, it kills any one.
I think consumers units should be left to the qualified, not the mistified
Again spark is right, the incoming side is still live and extra care should be taken.
Personally i would buy a bigger split load consumers unit and get an electrician to fit it for you.
electricity has no prejudices, it kills any one.
I think consumers units should be left to the qualified, not the mistified
I agree with both of the last two posts. As I am an electrician it is easy to look at it differently than a normal DIYer. As I said if you are unsure, call an electrician.
Spark is right in saying an RCBO is a suitable device but I too would echo his comment about the cost, the are quite pricey, even from screwfix!
Spark is right in saying an RCBO is a suitable device but I too would echo his comment about the cost, the are quite pricey, even from screwfix!
Apart from the cost RCBO's only appear to go up to a 40amp rating anyway and that's too small for a 10.5KW shower so that's one option out of the way. Personally I would go for the split level board change, not much dearer than buying a shower consumer unit (if you shop around)and you will have better protection for the whole installation
RCBO's certainly are available in ratings greater than 40A. I think what alexnic is getting confused with is that the most commonly rated RCBO's are those rated up to 40A, and are therefore the only ones that are factory assembled. You can get B,C or D type RCBO's anything from 1A to 63A MCB rating and anything from 10mA to 500mA RCD trip currents. Not all maufacturers are this flexible and depending on your board, you may be more restricted. If you don't want to change your board, I'd still go for a stand alone RCD in an enclosure, try screwfix.
Cheers for the RCBO info Spark .... only fitted a few and they were 40A and under usually in domestic or the odd catering application.
TLC's 6x6 Wylex split load board is a great buy well designed and easy to fit.... best option I would think
TLC's 6x6 Wylex split load board is a great buy well designed and easy to fit.... best option I would think
The reason I posted originally was because I had already replaced the existing MCB for a RCD and it doesn't appear to work, it won't trip on the test button but does trip when you switch the shower on. Therefore I just wanted to see if I had done it right. I have no idea why it doesn't work and that is probably the best reason for getting a sparky in, not to mention the dangers etc...
Another question then, what should I be realistically paying someone to come in and sort it?
Another question then, what should I be realistically paying someone to come in and sort it?
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