Hi
I found an EV charger today with built in type A RCD + RDC-DD connected to a type AC RCD in the consumer unit, the AC RCD is also protecting 3 other circuits including sockets. I know this is incorrect because the type AC RCD could be blinded by DC currents, but I am struggling to find a regulation to reference when providing information to the customer?
Thanks
Alan
A Type B may be required. A type A is suitable when the charger (or circuit) incorporates a RDCDD. If there is no RDCDD then a type B RCD is required. Details in section 5.6.1 of the code of practice or 722.531.3.101 of the big brown book
There’s much speculation on determining what RCD should be selected. The reality is it’s getting difficult to buy AC RCDs, all the standard RCDs and RCBOs in my local wholesale places are now A types. You can get a type B or F if you bring them a wheel barrow full of gold bars.
I have recently been installing external lights at a domestic property. I found that the AC RCD did not trip when tested. I isolated all MCBs and it did. The culprit was the kitchen ring circuit, very posh digital appliances in that kitchen, including a very naughty fridge and washing machine. I whipped that RCD out and replaced it with exactly the same model which as standard from Hager is now an A type. No problems even with the naughty fridge connected, interestingly when I tested it on the A type setting on my fluke 1664FC I got the exact same results when testing it on the AC setting, so I’m not sure what the difference there is. It was a really nice fridge, it had a touch screen and you could order more milk and eggs right there on the fridge. It apparently can be set to automatically detect when your eggs or milk are running low and automatically add them to your online shopping list. We live in the future but for now I’ll keep going down the garden to collect my eggs in the traditional analogue way! I like frying an egg that’s still as warm as the chickens bum!
If Type A RCDs have been generally installed for longer on Mainland Europe, but only on circuits with appliances known to have issues with DC leakage, does the new UK requirements to have them on far more circuits mean there’s problems that are not being dealt with in the rest of Europe?
This discussion is starting to lose continuity with too many new posts being added to posts from a few days ago.
If Type A RCDs have been generally installed for longer on Mainland Europe, but only on circuits with appliances known to have issues with DC leakage, does the new UK requirements to have them on far more circuits mean there’s problems that are not being dealt with in the rest of Europe?
I was under the impression that the German regs had moved over to minimum A-type RCDs quite a while ago - the French might be a little behind (or Legrand's website might not be entirely up-to-date). There's still no single European standard, but lots of (differing) national ones, often with different lifecycles. I guess we're all playing catch-up to some extend with this problem with UK neither in the lead or lagging too far behind, but in the middle of the pack somewhere.
- Andy.
CEF are notorious round here for inflated prices and often over charge or bump up numbers on your order…. Apparently the branch managers get a commission on sales so that says it all really. I found a B type RCD recently for £50. Could be worse
Currently Screwfix are selling all ratings of BG 30 mA Type AC RCDs off for £12.25 each, but Type A are not held as local stock and are next day delivery, a cynic might say to encourage people to have the Type AC that are in stock and half the price.
However their BG consumer units also still have Type AC in them as well, so may need swapping out making them less of a bargain.
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