RCD types and DC current

[Selfmade]

So, this article https://electrical.----------/wirin...----/wiring-matters/issues/77/which-rcd-type/ seems to suggest we should install a type F RCD wherever a washing machine is found (among other things). Is anyone actually doing this? If not, how do we justify not doing? Both BG & Wylex CUs at Screwfix both still come with AC RCDs as far as I can see. Further, most appliances in domestic premises are plugged in, so how can we have any idea what might be used there, and so whether it might produce DC fault currents?
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The link is being changed when I post and so is not working. The article can be found on the IET's website under

• Wiring Matters
• Years
• 2019
• 77 - September 2019
• Which RCD Type?

 

[AJshep]

e5 have done some brilliant podcasts and videos on YouTube regarding this, well worth checking out.
Wiring matters had an article in around the end of 2017 about RCDs and since reading that I've been installing A type RCDs, and since the 18th I've only installed RCBO CUs I've never installed a F type or a B type yet, but I'm aware that some washing machines with synchronous motors state that they need protecting against a high frequency leakage, which can render normal RCDs useless.

John Ward has also done some brilliant videos about the effects of pulsed DC on AC RCDs.
I think in due course AC RCDs will be non compliant like they are in some other European countries.

 

[snowhead]

so how can we have any idea what might be used there, and so whether it might produce DC fault currents?

Only the appliance manufacturer would know if they are using D.C and there's a fault risk, much like Electric Vehicle charging.

 

[Selfmade]

... I'm aware that some washing machines with synchronous motors state that they need protecting against a high frequency leakage, which can render normal RCDs useless.

Only the appliance manufacturer would know if they are using D.C and there's a fault risk, much like Electric Vehicle charging.

These points kind of illustrate my thinking: are we really supposed to read the manuals of all the appliances in a house before specifying RCDs? Is anyone doing that? And with the best will in the world, we could go into a house with a twin-tub, fit AC RCDs, then next week the customer buys a brand new washing machine with all the electronics and high-frequency leakage.

AJShep I will have a look for those videos, thanks.
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People have had audiovisuals (electronics) for decades. This starts to look like another example of manufacturers pedalling stuff which is not, and never has been, fit for purpose. ELCBs, plastic consumer units, and now seemingly AC RCDs.

 

[Selfmade]

e5 have done some brilliant podcasts and videos on YouTube regarding this, well worth checking out.

...

John Ward has also done some brilliant videos about the effects of pulsed DC on AC RCDs.
I think in due course AC RCDs will be non compliant like they are in some other European countries.

Some very good videos, thanks. Looks like I may be fitting more A type RCDs in future. It's just a shame all the dual RCD consumer units (except perhaps Hager) seem to come with AC type. I might also make a habit of watching the e5 channel and JW too.

 

[JK-Electrical]

e5 have done some brilliant podcasts and videos on YouTube regarding this, well worth checking out.
Wiring matters had an article in around the end of 2017 about RCDs and since reading that I've been installing A type RCDs, and since the 18th I've only installed RCBO CUs I've never installed a F type or a B type yet, but I'm aware that some washing machines with synchronous motors state that they need protecting against a high frequency leakage, which can render normal RCDs useless.

John Ward has also done some brilliant videos about the effects of pulsed DC on AC RCDs.
I think in due course AC RCDs will be non compliant like they are in some other European countries.

I too no longer install dual RCD boards, having switched to A type RCBOs since the 18th edition came into effect. Apart from the better protection that A type RCBOs offer, fitting these RCBOs will ensure that regulations 531.3.2, 536.4.3.2 and 536.4.202 are complied with.

I think the AC type RCD has had its day and is now all but redundant. I expect these devices to be phased-out in due course, perhaps around the same time as the IET eventually decide to make AFDDs compulsory, as no doubt they surely will.