4mm ring

[markyspark76]

Hi,I just wonder if how many of you would test a 4mm ring for ring continuity .The reason I ask is that a chap I work with testing has said a lot of sub contractors don't test 4mm ring as it can carry 32amps if the ring was broken.i my self have always tested ring regardless of conductor size, would be good to see what you think

 

[Manator]

I would test it if it was a 25mm ring!

 

[Zeespark]

You should test ALL installed work, though they are right as 4mm 6242Y can carry 32A.

AndyGuinness

 

[Andy™]

You should test ALL installed work, though they are right as 4mm 6242Y can carry 32A.AndyGuinness

actually, the 4mm may not be able to carry 32a due to insulation. which is probably why its wired in 4mm instead of 2.5 in the first place

 

[Zeespark]

I was merely going by numbers Andy, I apologise if I have gotten it wrong.

AndyGuinness

 

[ProDave]

Or it might be 4mm because it's a long run and otherwise might be excessive VD.

Whatever reason, it needs testing properly. It's not like it's a difficult test is it?

 

[Evans Electric]

So what are we saying here ? Anything over 4mm need not be tested ?

Or when filling out the cert , circuit 2 is left blank and a note on the cert saying "Not tested because its 4mm"

No it doesn't wash TBH Marky ,

 

[markyspark76]

The reason I asked is that we are testing a accommodation blocks on an army camp and have 100+ rings to test most are wired 4mm single live and cpc should I keep testing the rings or not. one block the Zs was excessive on all the rings but was protected by a rcbos do I test the ring or not!!

 

[wozz]

4mm LSF rings in schools were the norm during my apprentiship brill to second fix.

I think the op is referring to test them as a radial rather than a ring due to apparent ccc of cable rather than not testing at all.

 

[Sidewinder]

IF they are a Ring Final Circuit, then they MUST be tested as such, regardless of cable size.

There are other factors that will influence CCC rather than just the base rating of the cable.

 

[Manator]

Testing is fundamental, the continued use depends on the findings of that testing otherwise what is the point in testing at all.

The only limitations to testing are those that are agreed BEFORE any testing is carried out, so in short, yes you should continue to test each and every ring.

 

[Sidewinder]

Manator,

I'm guessing you are reading this as a "PIR", I am reading it as an "EIC" situation?...

 

[markyspark76]

The subbys in question would see two 4mm cables on a breaker and straight away would not even consider to test for a ring (they work for a large testing company,the more they test the more they earn )

 

[Sidewinder]

Shoot them, or arrange for Darwinian selection to take over, as they are incompetent.

 

[Revved Up Sparky]

......the more they test the more they earn

This I feel is where inspection and testing can get dangerous. Selfish greed takes precedence over electrical safety.

 

[Manator]

Manator,I'm guessing you are reading this as a "PIR", I am reading it as an "EIC" situation?...

Looks like a PIR from the description, any new installation would be tested as a matter of course.

 

[Sidewinder]

Emma Shaw anyone?...

 

[Manator]

Emma Shaw anyone?...

Exactly mate, one needless and avoidable death

 

[Sidewinder]

OK M,

IF it is an EIC, can they be sure that the 4mm will carry 32A for its fully installed condition if it is not in a ring configuration when it was required to be so by the original designer?...

I doubt it, so incompetence I suspect...

 

[Manator]

OK M,IF it is an EIC, can they be sure that the 4mm will carry 32A for its fully installed condition if it is not in a ring configuration when it was required to be so by the original designer?...

I doubt it, so incompetence I suspect...

Agree