RCD, Ze,Zs Instrument Testing

[calltronics]

Hi All,

With reference to verifying your RCD instruments on-going calibration.

I've heard and read so many times about verifying your RCD tester on a known socket for trip times and Zs

Have any of you come across a definitive document detailing this procedure?

Or can someone write one for me?

I keep getting asked all the time for this and I never have a definitive answer.

I Just issue my usual waffle but I

 

[kme]

OK - it isn`t complex.

Zs - unless you`ve got an "iffy" TT, your Zs won`t change much, to a given socket, at any time.

So you nominate a Zs testing socket ("left hand socket outlet in the office" for instance), and, when doing Calcheck, plug in & do Zs on that particular socket.

n.b. if your tester trips RCDs, install a socket adjacent to CU, on a 6A MCB, and label "testing only" - don`t put this socket through an RCD.

RCD tests - exactly the same. If possible, an RCBo cct for testing, so you don`t have to reset clocks in the house, etc. Same RCD / RCBo, under same conditions - test results should stay comparative.

That`s it, really mate.

HTH

KME

 

[sparkytim]

+1

I use a Non RCD protected socket adjacent to my Consumer Unit for Zs and a Plug in RCD kept just for the purpose + Calcard for other tests.

 

[NozSpark]

+1I use a Non RCD protected socket adjacent to my Consumer Unit for Zs and a Plug in RCD kept just for the purpose + Calcard for other tests.

+1

except I made my own:innocent

 

[kme]

I use the calcard (excellent kit), and have an RCD socket beside the CU, on a B6, from the hi-integ section of the board.

the intention is to eventually have all ccts on RCBo`s, as I pick up "spares"

 

[calltronics]

Thank you so much.

You've confimed my undertanding.

I've been receiving e-mails questioning this procedure and started doubting my understanding!

I couldn't believe it was that easy and thought I missed something!

cheers all

 

[calltronics]

So I've cobbled together all the information and instructions picked the bones out and put together a document that I can simply refer customers too when they enquire.

It's located at http://www.testcal.co.uk/Pages/Documentation/Instructions.html

It would be great if you experts could have a look just to make sure its not only comprehensive but most importantly correct.

I

 

[NozSpark]

Just had a look at your pdf..

I think you misunderstood what kme was saying, the test socket is not rcd/rcbo protected, its just fed from a mcb - first do your Zs test then plug in RCD and carry out RCD tests. Then do your ohms and IR tests.

You could of course have 2 test sockets... one supplied via a mcb and the other by a rcbo.

Any socket that isn't rcd protected requires a label to state it's use.

 

[Apache]

Just had a look at your pdf..I think you misunderstood what kme was saying, the test socket is not rcd/rcbo protected, its just fed from a mcb - first do your Zs test then plug in RCD and carry out RCD tests. Then do your ohms and IR tests.

You could of course have 2 test sockets... one supplied via a mcb and the other by a rcbo.

Any socket that isn't rcd protected requires a label to state it's use.

Or a radial with the first socket no RCD and the second either an RCD socket OR via RCD fused spur or plug in type?