Does this comply with 314?

[Deleted member 9648]

Makes sense to me, I do think that a lot of this accumulated current can be a bit of a myth though.

I work at a site where there are two IT suites each with 20-30 PC's all fed from a TPN DB with a 30ma RCD main switch. It never trips...except when it's tested.

 

[Wilko]

By the looks, the reg makes us responsible for equipment leakage in the installation design. For me to do that, the appliances would need to have a stated and rated leakage current. Or have I misunderstood?
Just now I can't recall working on a domestic dual RCD installation that was tripping for reasons other than a fault.

 

[Phil Thompson]

By the looks, the reg makes us responsible for equipment leakage in the installation design. For me to do that, the appliances would need to have a stated and rated leakage current. Or have I misunderstood?
Just now I can't recall working on a domestic dual RCD installation that was tripping for reasons other than a fault.

Same here, I'd one a fortnight ago, cheap 4way extension lead.

 

[telectrix]

I am not aware of those proposals, are you saying it is proposed that a 63a RCD would be restricted to a load of 21a?.....then presumably a 32a RCBO would be restricted to under 11a?
So a 10kw shower would need a minimum 135a RCBO ?....Sorry if I'm having a blonde moment but that just doesn't make any sense.

as i read it, it's talking about leakage currents not being more than 30% of the mA rating of the RCD, unrelated to load current.

 

[Midwest]

Since my #25 (trying not to big myself up too much here ),it has brought numerous comments and posts on 531.3.2 (draft 18th).

You'd been surprised perhaps, that the draft has only collected a few comments on this new proposed reg, which therefore may see its introduction in the 18th.

In fact the current '531.2 RCDs', will be Over Current Protective Devices. RCDs will be moved to 531.3, as far as I can make out. This includes the reg on unwanted tripping, as well as some other changes; '531.3.1.201 Except in certain special installations or locations (Part 7), for protection against electric shock, there is no requirement to disconnect/switch the neutral in TT or TN Systems'. Haven't noted that before, seem to recall members stating the opposite previously for a TT system (SP RCBO's)?

Apologies for hijacking your thread Murdoch, but you started it

 

[Octopus]

^^ ha ha.

Seeing as nobody can explain why we can fit dual board now, I have come to conclusion that my interpretation of 314.2 is correct in the op and my example stands as a non compliance to the regs.

 

[Octopus]

By the looks, the reg makes us responsible for equipment leakage in the installation design. For me to do that, the appliances would need to have a stated and rated leakage current. Or have I misunderstood?
Just now I can't recall working on a domestic dual RCD installation that was tripping for reasons other than a fault.

It's abundantly clear that the 18th will add further confusion to the regs.

Do the people who dream up these changes actually consider the impact of what they write and add. I don't think so

 

[seltechpc]

I decided to make up a small extension lead with the earth broken out so I can check the earth leakage of various plug in appliances by clamping the L+N.
It was very revealing, I checked 3 Miele appliances and found they were all around 3mA leakage; one of them was a brand new dishwasher. The leakage increased slightly when switched off on the machine. A Neff induction hob I clamped the cable and measured 2mA leakage.
These leakage currents add up and may be the reason that the proposed 18th edition is specifying a limit of 30% of the RCD trip current. Problem is I do not see how a sparky will know what appliances the householder will plug in, and will he have to check items that are hard wired like hobs. I think it is all the filters fitted to modern day electronic appliances that is giving rise to increasing leakage currents.
The only way around this, unless I am missing a trick is to fit all RCBO boards, even then you could easily exceed the 30% RCD current on 1 ring final.

 

[Midwest]

I clamped my own house the other day. PC running, few led lights on, tv on, appliance turned on but not running. Clamp meter's a cheap en, but I had 14mA leakage. But I've have that split across RCD & RCBO's. Went to a job in the afternoon, semi with 1 x lighting, 1 x RFC & electric cooker. 9mA eath leakage.

^^^ ditto

 

[Octopus]

The only way around this, unless I am missing a trick is to fit all RCBO boards, even then you could easily exceed the 30% RCD current on 1 ring final.

Hit, nail and head spring to mind..... I stopped fitting dual RCD boards when AMD3 boards arrived - far, far, far better when something trips.