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Topic Title: Memshield 2 RCBO
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Created On: 22 November 2014 11:59 AM
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 22 November 2014 11:59 AM
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Zs

Posts: 3814
Joined: 20 July 2006

Before I lose the details.

I've been searching for an RCBO for use in a Memshield 2 TPN DB on a single phase.

I don't do second-hand kit and places like ebay not good for 50A type C. This has been a bit of a trawl.

But, Eaton do a pod which locks on to the top of an MCB and here are the part numbers for you.
The Pod is MSH2 30ma field fit RCD POD, cat no MR30 . Cost £67.19 plus VAT. Yes, that's ma not mA.

The breaker is a straightforward Memshield 2 Type C, £11 odd plus VAT.

It's a once only fit and cannot be removed from the breaker. It's just taken a bit of a process to fit it but mostly because of the price and their massive disclaimer about buggering it up, so I took some time and followed the pictures. The pod comes with all the bits you need to adapt the length of the clip and a new badge with cut-out for the test switch.

Because of the price, I suppose a bolt-on small DB might have been an option but in this case it's the stables and I don't wish to make changes or extend cables if I can avoid it. Off to fit it now but thought I'd let you know the model numbers before I forget them.

Zs
 22 November 2014 12:31 PM
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slittle

Posts: 3678
Joined: 22 November 2007

We've used loads of them Zs, you should of asked

Annoyingly they haven't carried the pod over to memshield 3 as they were great to keep in stock to get over needing RCD protection on a circuit without a return trip to get an RCBO.

You can get them back off if you are really careful (it's been done) but it's not a sport for the faint hearted.


Stu
 22 November 2014 07:50 PM
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markwatson

Posts: 27
Joined: 26 May 2006

Yes they are useful as a get out of trouble option and I've managed to get one apart carefully before.
From memory I think you have to test them after the output terminals otherwise they don't give the right results.

Mark

-------------------------
sparkymark
 22 November 2014 09:27 PM
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prophet

Posts: 338
Joined: 09 October 2011

I did think Eaton had brought out an RCBO to avoid having to buy and fit the pod. I think i have some part numbers somewhere.

Tom
 23 November 2014 09:56 AM
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hertzal123

Posts: 468
Joined: 26 August 2007

Originally posted by: markwatson

Yes they are useful as a get out of trouble option and I've managed to get one apart carefully before.

From memory I think you have to test them after the output terminals otherwise they don't give the right results.



Mark

Can confirm that you have to test the rcbo at the end of the cct.Took mine back to Eddys thinking t was faulty.
Regards,Hz
 23 November 2014 10:59 AM
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Zs

Posts: 3814
Joined: 20 July 2006

Hertzal and Mark,

Thank you so much for the tip off. I'm over there today and hoping the horses will be out at an event, so I may test. Last time they turfed them all out for me the supply cable failed its tests in spades (edit, armour to neutral fault) and I'm in the throes of replacing a whole chunk now. Could do without the extra time it is taking but it goes well (in the rain). It's not the horse poo that annoys me it's the dog stuff. I try to keep my humour.

If you remember, I've long been an advocate of RCD testing at the end of the circuit and not at the board and I have to confess to feeling slightly validated by your advice.

Many thanks for that, on both levels.

Zs

Edited: 23 November 2014 at 11:08 AM by Zs
 23 November 2014 11:40 PM
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mapj1

Posts: 9387
Joined: 22 July 2004

Can confirm that you have to test the rcbo at the end of the cct.Took mine back to Eddys thinking t was faulty.


Actually, you really mean you can't test them from the terminal screws, taking the test current out the front - the construction is such that the bit of wire of the final circuit becomes the current transformer primary turn as you push it in from the top. If you can fiddle probes or bits of wire in from the top, the way the wire goes in, then you can test them that way, which rather depends how its located and if the tunnel is already too full of wires to sneak one more in.

-------------------------
regards Mike
 24 November 2014 05:37 AM
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GeoffBlackwell

Posts: 3793
Joined: 18 January 2003

Sharp thin needle probes (not inserted into the terminals) can do the trick

Regards

Geoff Blackwell
 24 November 2014 09:29 AM
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mapj1

Posts: 9387
Joined: 22 July 2004

But stabbing through the insulation (vampire testing) is not really in the spirit of GS38 complaint probes- or do you have another trick in mind.

And if you do mean vampire testing, do you attempt to fill in the hole with a light smear of something afterwards.
(thinking clear mastic or grease, or perhaps a turn of tape....)

-------------------------
regards Mike


Edited: 24 November 2014 at 05:03 PM by mapj1
 24 November 2014 01:14 PM
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GeoffBlackwell

Posts: 3793
Joined: 18 January 2003

Oh I couldn't possibly comment - suffice to say that many things are possible if the need exists and the pubs are open .

I did take one of these units apart and I can confirm that the terminals are the wrong side of the sensing coil - the conductors pass through the coil and then into the terminals.


EDIT
Just checking this and as I have answered questions about this unit two or three times before - to quote one from 2009

Is this an RCBO or an RCCB.

If it is an RCBO some makes will not trip if you apply the test at the terminals. This is because the line terminal is the wrong side (upstream)of the search coil.

When you test at a socket the line and neutral connections are both the right side of the search coil (downstream).

Regards

Geoff Blackwell


Regards

Geoff Blackwell

Edited: 24 November 2014 at 01:37 PM by GeoffBlackwell
 24 November 2014 05:03 PM
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ebee

Posts: 6340
Joined: 02 December 2004

I don`t think I`ve seen these.

I think that removing the circuit conductors and putting small wirelinks to get your tester alligator clips on (OK rough) or wing in a temp trailing socket on a short piece of T&E to plug your tester into might be advisable .

-------------------------
Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 24 November 2014 05:07 PM
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mapj1

Posts: 9387
Joined: 22 July 2004

Ah well, quite so, and I'm not saying I haven't vampired in at some point or that I wouldn't ever do it again. Just that I'd like to try and make sure the damage wasn't going to cause a problem later.

In a perfect world one would do it under the numbered ident sleeve that the initial installer used to label his wires, and slide it along to cover the pin hole afterwards.
But then of course just occasionally, there isn't any such sleeve to slide along.
Edit - I know -a little label printer making a small numbered flag -solves both these problems at one stroke !!

These vampire probes
make a right mess of your leg if you leave them stuffed hurriedly in your pocket and then sit down..

-------------------------
regards Mike


Edited: 24 November 2014 at 05:36 PM by mapj1
 24 November 2014 05:19 PM
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GeoffBlackwell

Posts: 3793
Joined: 18 January 2003

Originally posted by: ebee

I don`t think I`ve seen these.



I think that removing the circuit conductors and putting small wirelinks to get your tester alligator clips on (OK rough) or wing in a temp trailing socket on a short piece of T&E to plug your tester into might be advisable .


I sure your right ebee - but just out of interest see here. The needle probe is the thin one .

Regards

Geoff Blackwell
 24 November 2014 08:23 PM
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Zs

Posts: 3814
Joined: 20 July 2006

Every day a school day then?

I did not know that this was called vampire testing and I love that. Seen it, done it many times. But this one was tested this evening in the freezing cold and from the end of the circuit. It is a babe and all is well. Two soaking wet portacabins now being looked after by my dehumidifier until I get back from guitar playing. What a relief.

Confession...I can't abide pencils which are not put back into the pot needle-sharp and can happily while away time re-pointing my staedtlers before putting them in regimental lines in the drawer and at jaunty angles in the pot. My secret OCD and a possibly a bit silly but I don't think it's serious. So, I have the best electric pencil sharpener in the universe. Great if you stick an old probe into it .

Zs
 24 November 2014 09:04 PM
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ebee

Posts: 6340
Joined: 02 December 2004

A graphite probe Zs ?



-------------------------
Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 24 November 2014 09:16 PM
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mapj1

Posts: 9387
Joined: 22 July 2004

I did not know that this was called vampire testing


In the days of old when computer networks were wired in coax, and not twisted pair, and computer folk to a man all sported long hair and sandals, there were also these things
Vampire taps
which were quite a bit more sophisticated as they picked up core and braid separately, well, usually anyway, sometimes it all went horribly wrong..

Some festoon lights work on the same basis of teeth that stab the wire.
I think we are supposed to talk about "insulation displacement connections" nowadays, but 'vampire' is easier to remember and a good mental picture. (teeth to get to the 'juice' inside)
(We are also supposed to talk about internal and externally threaded parts nowadays instead of male and female threads, but that's another transition to modernity I've not yet made)

-------------------------
regards Mike
 25 November 2014 10:06 AM
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OMS

Posts: 22359
Joined: 23 March 2004

Talking of vampire testing, I found an old set of GEC fuse holders the other day - these were designed to physically clamp to a large cable and as you tightened up, the needle penetrated the insulation and allowed you to take (usually) an instrument voltage off the cable.

I've put a few on "live" over the years in conjunction with "split" CT's to get metering onto a supply - such fun

OMS

-------------------------
Let the wind blow you, across a big floor.
 26 November 2014 01:14 PM
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whjohnson

Posts: 934
Joined: 24 January 2009

I have used loads of the MR30 retrofit pods.
You can get them on and off quite easily.

Firstly, remove the DIN rail clip (black plastic) from the back of the mcb - it only pushes out one way.

Prise off the top front cover of the mcb - easily done with a small terminal driver.

Clip on the pod assembly by locating the pins and slots on the back first, then swing the front of the pod down onto the mcb and click it into place.
Push on the new front cover with hole for test button.
Slide the longer replacement DIN rail clip down the back to the assembly.

Connect up and Test and you're done.

I don't understand the manufacturer's warning notes - I've swapped loads of these units in and out and have never had a problem.

-------------------------
Political correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.
 22 February 2015 01:45 PM
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Cornelec

Posts: 1
Joined: 21 February 2015

Ok, new here, so go easy!!

I think I already know the answer to this question but we were asked by a local school to replace the MCB's in a Memshield 2 board with RCBO's. All the wholesalers came back with the same solution - the RCBO pods referred to above.

We lost the job to a contractor who fitted a load of (Far Eastern) imported RCBO's - circa £11 each from an online retailer.

So the question is - this will invalidate the warranty and certification of the board, right? Can anyone tell me whether, in their opinion they feel this also contravenes any other regulations - WR 530.3.4 "....a consumer unit incorporating components and protective devices specified by the manufacturer...."
 23 February 2015 01:39 PM
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AJJewsbury

Posts: 15855
Joined: 13 August 2003

Can anyone tell me whether, in their opinion they feel this also contravenes any other regulations - WR 530.3.4 "....a consumer unit incorporating components and protective devices specified by the manufacturer...."

I doubt it's a breach of 530.3.4. That reg primarily applies to household situations - in a school you're perhaps unlikely to have a <= 100A supply to the entire installation, nor be relying on Annexe ZA for breaking capacity (i.e. trusting to hope that a 6kA MCB in a plastic box is suitable for a 16kA PFC). Even if it was <= 100A etc, I suspect you'd go down the reg 432.1 route (i.e. have MCBs suitable for the PFC or backup HBC fuse).
- Andy.
IET » Wiring and the regulations » Memshield 2 RCBO

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