Type B rcd's

[Adam_151]

For anyone not familiar, the Memshield 2 RCBO is assembled, in the factory or in the field, by snapping an RCD pod onto a MCB. They are made to fit together, and this enables a very wide range of options to be built.

I seem to recall, that they have pulsating DC protection, but do not seem to be listed on a search of "Eaton" and I don't have the technical literature from the time.

I found a spec of the MR30 on a distributors website that says "tripping class A" which is what we now prefer.

Can we have a pic John (focuses around the test buttons) , The ones I found online were indeed type A, however I do wonder if all of them were, the Mem2 range was current from 1997 up until 2009, and I's say a type A rcbo in the 1990s would have been unusual but not impossible

 

[ericmark]

I looked at adverts and technical spec for a MK 10 mA RCD socket outlet, and there is nothing to say type A or AC, but it does say AC and pulsing DC so one would assume type A.

I note many adverts now refer to curve B not type B when referring to MCB's, but not all, I still have the paper work for my RCBO's, it states "Tripping Curve B, C. Residual Operating Current (IΔn) 30 mA it includes the test procedure.

When newly fitted systems do not trip on the TEST button or using the RCD tester the problem is normally caused by an earth to neutral fault on the circuit (PME supply).
Installers can easily check the RCBO by removing the LOAD connection on the RCBO and applying power. If the TEST button works the fault is the circuit.

What do you make of that?

The only indication anywhere on the RCBO to show it was not type B as written on the box was a very small logo with just a single sine wave depicting type AC on the paper work it calls it curve B, C on the box it was written type B.

I looked on the screwfix web site to see what type A RCD's and RCBO's were available. For RCBO's it does not say what type, the BG picture shows it is type AC, the Wilex picture shows it is type A, MK picture shows type AC, Eaton picture shows type AC, Schneider picture shows type A, but the description does not actually say what they are, you have to enlarge the picture to find out.

RCD's there are 25 on offer, 7 are type A, one is a type S 100 mA time delay picture shows as type AC, the Schneider iKQ is called a double pole 3 phase RCD, work that one out.

But in the main the RCD comes with the consumer unit, and even that seems wrong, first on screwfix list, 16 module BG high integrity with 2 x 63A RCD's and 3 x 6A, 2 x 16A, 4 x 32A & 1 x 40A MCB's can you work out any combination which insures no more that 63A on any RCD? Yes you could use some RCBO's but it comes with 10 MCB's and 6 modules taken up with the isolator and RCD's so fully populated. No surge protection device. I don't blame Screwfix it's how the manufactures package them. And my house still has a 60 amp fuse, so 63A RCD would be OK. But it is very cheap at £68, I paid over £200 for mine with all RCBO's and that was cheap.

Point is the type A or AC is not the only problem, we are getting new consumer units fitted which are not fit for purpose. And the whole sale outlets are hiding vital details in the hope we will not notice.

 

[JohnD]

Can we have a pic John (focuses around the test buttons)

Ah, I see what you're looking for now.



Yes, conveniently printed, very tiny, in mid-grey on the light-grey plastic, both the AC Sine wave and the pulsating DC gappy teeth are shown.

There is nothing else on the box label, or printed on the device itself, to indicate.

I don't know if "E1" or "R30" are significant.

Curiously, although I see that Memshield (edit - sorry - Memera) RCBOs are only about £30, they are a later (German?) design, and AC, whereas the MR30 pods, to the old MEM design, are "A" and around £100.

perhaps I should sell my spare ones.

 

[Adam_151]

That confuses me, I thought the Germans were far quicker than us realise the difference in RCD types and had been using a minimum of type A for years...

 

[JohnD]

yes, there is reference to type "A" being preferable in the Eaton document (in English) about RCDs I found on a German page.

But Memshield is more commercial and industrial than domestic, perhaps Screwfix are selling the cheapest version, or don't know the difference.

Edit
My mistake
Screwfix are selling a Memera RCBO, so it probably won't fit Memshield2 which has bigger teeth on the busbar. I don't know if it will be on the German market, and Memshield3 is different..

The ones I have were Memshield2, which can be used in Memera and Memera 2000, but the budget Memera 2000 version (without red/green window) would not fit in Memshield, and did not accept the Pod.

 

[flameport]

I thought the Germans were far quicker than us realise the difference in RCD types and had been using a minimum of type A for years...

That's correct, but it would only apply to RCBOs / RCDs used in Germany. nothing to stop German companies making type AC provided they were used elsewhere.

The standard for RCBOs (61009) and RCDs (61008) allows the use of Type AC, but has a special note for Germany where type AC is not permitted.

 

[ericmark]

That's correct, but it would only apply to RCBOs / RCDs used in Germany. nothing to stop German companies making type AC provided they were used elsewhere.

The Germans are good at that, the batching plant I had my accident with was made so it did not comply with either German or British rules. It seems it was made for some third world country, but ended up in UK.

When people charge for PAT testing by item, I do wonder what they would do with that, it was portable it came and went behind 22 articulated tractor units, to inspect and test took three electricians two Sundays, it ran every other day.