Board change and the use of rcds

[APE37]

Hi guys.
Looking for a bit of advice if poss.
Looking at changing a board as part of an assesment. Looking at the new regs it states that the use of type a rcd now should be used. But I have had conflicting info from others saying ac is still ok? I know type a is for the allowance of detecting DC faults and I have also noticed that in wholesalers and other places boards are still with ac rcd. Just looking at getting some info as i dont want to get pulled up on it as I see it it should be a type a now for domestic but cant see why it seems still the norm for ac rcd to come with the boards. If anyone can give me some clarity I would be grateful.
Cheers

 

[HappyHippyDad]

I very, very much doubt the assessor will even notice this let alone pick you up on it.

However, I know how you feel as I remember my first assessment and you just want to try and cover absolutely every eventuality.

The regulations do not say you have to use a Type A RCD, they state you have to use the 'appropriate' RCD (531.3.3). They also go on to say "For general purposes, Type AC RCD's may be used. (See end of Note 3 reg 531.3.3).

In the unlikely event the assessor does mention the type of RCD you can then show him that you have an understanding of this and also justify your use of a type AC RCD by quoting the reg. That is of course if you deem the Type AC RCD to be suitable, which it probably is.

 

[HappyHippyDad]

A quick follow on... I'm a bit confused as to why a number of people are saying a Type A RCD has to be used. I realise they may well be a good idea and also I have seen the hagar video with their new board with Type A RCD's but I am unaware of any regulation saying a Type A 'has' to be used. Does anyone know where this myth is coming from?

 

[Bobster]

A quick follow on... I'm a bit confused as to why a number of people are saying a Type A RCD has to be used. I realise they may well be a good idea and also I have seen the hagar video with their new board with Type A RCD's but I am unaware of any regulation saying a Type A 'has' to be used. Does anyone know where this myth is coming from?

Not sure, I know more an more tech found in households have switch mode power supplies etc... an can introduce a DC ripple on the AC waveform. This can saturate the sensing coil on standard RCD's causing them not to function.

As for the myth, I guess the same as AFDDs, someone somewhere has a good marketing team. As I presume the 'A' type RCD's are more expensive still.

 

[APE37]

Hi hhd and rob
Thanks for the input. I was under the impression now that type a needs to be used as they deal with DC faults, and with more people installing led lighting, newer TVs, kitchen appliances, that all have DC components type ac was not suitable? May be just a myth but as said dont want to be caught out. Once again thanks for all your help in this matter.

 

[Deleted member 26818]

Type A RCDs are for use, where the dc leakage is not greater than 6mA.

 

[APE37]

yes spin I did realise that. But would have thought that with new appliances it would be required.

 

[Markyd]

seems to me that afdd's as a buzzword has been worn out......and the new buzzword is type A rcd's

 

[Toneyz]

It is all a marketing hype read what the regulation says, what is the regulation trying to achieve in this case is there a risk that the load will require a type A RCD/RCBO.