schedule of test results

[chicd4]

My lighting circuits are on type b 6 amp mcb's on a 30ma rcd at the CU.
Can't do an efli on those circuits as they trip. What do i put in the ELI column relating to those circuits. Can I just put a note in the remarks column that they are sensitive to the test.

 

[electronicsuk]

My lighting circuits are on type b 6 amp mcb's on a 30ma rcd at the CU.
Can't do an efli on those circuits as they trip. What do i put in the ELI column relating to those circuits. Can I just put a note in the remarks column that they are sensitive to the test.

Get a new tester with a non-trip EFLI setting?

 

[shetland]

Add your R1+R2 measurement to your Ze measurement.

Zs=Ze+R1+R2

 

[chicd4]

Thanks Shetland, sounds cheaper than a new test instrument.

 

[Adam_151]

Or naughty naughty... but move the circuits to the none RCD side while you test.... not the proper way, but at least you get a number that might be worth writing down...

 

[sparkyspike]

No - you're not supposed to measure EFLI on individual circuits. Measure Ze with your tester (nothing will trip) and then measure R1+R2 to get Zs. This is the correct way to do it.

 

[Spark123]

I don't know about not supposed to??
To me either way is acceptable. I personally like directly measure the EFLI with the power on as shoving a few amps down a cable tends to show any problems whereas 200mA (R1+R2) doesn't always.

 

[holmslaw]

..

 

[sparkyspike]

You're not supposed to undertake live testing if it can be avoided. So for a lighting circuit for example, you would do R1+R2+Ze.

 

[flameport]

Direct meansurements of Zs are really only of use to confirm what you already know.
Adding Ze and R1R2 is the usual way, with any Zs test just to confirm that Zs is either equal or less than the calculated value. (usually it will be less due to parallel earth paths).

Non-trip testers limit the testing current to 15mA, so this really proves nothing regarding loose or corroded connections.

To really test Zs you need one of the old type testers, which typically applied a test current of 25A or more for many tens of seconds. Unfortunately, this type of testing can result in significant voltages appearing on the exposed metalwork in the property - plenty enough to injure or kill people.

 

[JonoPashley]

Wouldnt it be ZE + ((R1 + R2) x 1.2) to take into account the increase in temperature when the cables are running at operating temp?

 

[Goldberg]

You're not supposed to undertake live testing if it can be avoided.

You're imagining things.

Using a non-tripping EFLI tester is not live working.

No - you're not supposed to measure EFLI on individual circuits.

So for a lighting circuit for example, you would do R1+R2+Ze.

So which is it? If you're not supposed to measure an individual circuit then why are you giving an example of lighting circuit?

And another thing - how do you measure R1 and R2 unless it's on an individual circuit?

 

[ColJack]

do you read your replies before posting them?
he says "no EFLI on individual circuits."..
R1+R2 is a dead test before connection..
EFLI is a live test .. 2 different things..

 

[Goldberg]

do you read your replies before posting them?

No. I write them.

he says "no EFLI on individual circuits.".

Pray tell the objective of measuring EFLI on anything other than an individual circuit.

R1+R2 is a dead test before connection.

That's nice.

EFLI is a live test.

A live test, but not live working. There's no law, or any other earthly reason, not to carry out a live test. Switching on a light bulb, or an appliance, or using a test lamp to test for dead, are all live tests that are not illegal.

 

[ColJack]

EFLI gets you the Ze at the source of the CU..
which added to the R1+R2 of the circuits gives you the calculated Zs..
I'm not saying that you shouldn't do Zs with the meter on individual circuits, just pointing out that you're trying to make Sparkyspike look contradictory when he hasn't been.. his argument is consistent..

I didn't mean the "EFLI is a live test" in the manner that it appears you've taken it.. I was merely pointing out that measuring R1+R2 and EFLI are 2 different things..
I agree that live testing is not illegal and does not constitute live working..