Testing RCBO's

Fitting a new CU tomorrow and the customer would like RCBO's on all 6 circuits, do I test them individually for ADS probe on each one L/N. earth probe on CPC buss bar. Not done these before only split load MCB unit.

RCBO's bought off this site advert so have twin wire N + E

Thanks

Chas

If you don't know how to test an RCBO, what are you doing fitting them?

If you don't know how to test an RCBO, what are you doing fitting them?

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Like I said I normally use a split load CU with 2 RCD's and MCB's, the customer wants RCBO's that's why I am fitting them

Just never used them before so not had to test them before... we all have to learn.

Fitting a new CU tomorrow and the customer would like RCBO's on all 6 circuits, do I test them individually for ADS probe on each one L/N. earth probe on CPC buss bar. Not done these before only split load MCB unit.RCBO's bought off this site advert so have twin wire N + E

Thanks

Chas

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Are you asking HOW do I test them...

i.e. where to stick me test leads?

and NOT

Do I test them individually?????

which I cannot see any way you can note the operating times for each RCBO if you don't test them individually!

Guinness

what sort of earthing system do you have?

and will SP RCBOs actually comply with the regs for the installation?

not all installations will comply with normal RCBOs fitted.

Like I said I normally use a split load CU with 2 RCD's and MCB's, the customer wants RCBO's that's why I am fitting them Just never used them before so not had to test them before... we all have to learn.

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and when fitting a dual split load, do you only test 1 RCD?

RCBO sequence

1. two tests at each waveform

2 x 'no trip' tests at 50% rated current

2 trips at rated current

2 trips at 150mA (5 times).

Shoot me down if i am wrong and each tested separetley.

you test both sides of the waveform 0, 180. Hence 6 tests.

finally press functional test button to ensure no mechanical damage caused during test to rcb/rcbo

you only need to do 1 test at 1/2

Why only on one waveform Andy, Im at college so would not profess to be completely knowledgeable and very little on RCBO testing in books I have

Why only on one waveform Andy, Im at college so would not profess to be completely knowledgeable and very little on RCBO testing in books I have

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its a 2 second test. 100 cycles will pass in that time, so starting it at the opposite cycle aint going to make a difference

at 5x, you may well get a trip withing 20ms. which is less than 1 cycle, so it needs done on both 0 and 180

RCBO sequence two tests at each waveform

2 x 'no trip' tests at 50% rated current

2 trips at rated current

2 trips at 150mA (5 times).

Shoot me down if i am wrong and each tested separetley.

you test both sides of the waveform 0, 180. Hence 6 tests.

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You must also not forget to do the functional checks using the test button. After you have done your electrical tests with the meter.

Doc H.

Like I said I normally use a split load CU with 2 RCD's and MCB's, the customer wants RCBO's that's why I am fitting them Just never used them before so not had to test them before... we all have to learn.

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Yes, we all have to learn, but we should learn the principles, and how to apply them. Learning the "monkey see, monkey do" method, then competing for my business pee's me off somewhat!

RCBO sequence 1. Functional test on test button

two tests at each waveform

2 x 'no trip' tests at 50% rated current

2 trips at rated current

2 trips at 150mA (5 times).

Shoot me down if i am wrong and each tested separetley.

you test both sides of the waveform 0, 180. Hence 6 tests.

finally press functional test button again to ensure no mechanical damage caused during test to rcb/rcbo

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NEVER press the test button first,

this is the last test you carry out, and only if all other tests are satisfactory,

the reason is that the RCD could have 'grown' together, and therefore would not trip in case of a fault, which will show on your tests,

pressing the button will usually mechanically force the RCD to open, thus now allowing it to trip on your tests,

but this would not happen in the real world fault scenario, you have artificially forced the RCD to work by using the button.

also, if on your first test the RCD fails, DONT test it again looking for a better result, the poor chap on the other end of a live cable wont get another chance.......

NEVER press the test button first,this is the last test you carry out, and only if all other tests are satisfactory,

the reason is that the RCD could have 'grown' together, and therefore would not trip in case of a fault, which will show on your tests,

pressing the button will usually mechanically force the RCD to open, thus now allowing it to trip on your tests,

but this would not happen in the real world fault scenario, you have artificially forced the RCD to work by using the button.

also, if on your first test the RCD fails, DONT test it again looking for a better result, the poor chap on the other end of a live cable wont get another chance.......

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Excellent mate, I feel that I have been banging on about the correct sequence of tests for RCD's and that we should only test once and not carry on testing until we get a good result

However I do it in a slightly different order

1x - at 0 & 180

5x - at 0 & 180

Ramp

Manual

1/2x

Under no circumstances do any of the tests get a second chance

nice sequence Noz,

I do something similar,

1 test at 1x

1 test at 5x

0 or 180 is random as to if I change the setting on my meter or not

then let my meter run its auto sequence,

then manual,

seldom do I do a ramp unless I get a 'feeling' from one of my results.

Yes, we all have to learn, but we should learn the principles, and how to apply them. Learning the "monkey see, monkey do" method, then competing for my business pee's me off somewhat!

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Sorry Riggy I don't work or quote for jobs in the Cumbria area so I can't see how I compete agains your business but thank you for your comments

Chas

NEVER press the test button first,

this is the last test you carry out, and only if all other tests are satisfactory,

the reason is that the RCD could have 'grown' together, and therefore would not trip in case of a fault, which will show on your tests,

pressing the button will usually mechanically force the RCD to open, thus now allowing it to trip on your tests,

but this would not happen in the real world fault scenario, you have artificially forced the RCD to work by using the button.

also, if on your first test the RCD fails, DONT test it again looking for a better result, the poor chap on the other end of a live cable wont get another chance.......

" if on your first test the RCD fails, DONT test it again looking for a better result, the poor chap on the other end of a live cable wont get another chance....... "

THATS THE BEST ADVICE I HAVE HEARD IN A LONG TIME ....

Used an Ideal brand tester today with the students on the 2391-10 exams, never used one before, but I did like the RCD test sequence.

x1, x5, x1/2.

I found it very basic, difficult to use not intuitive, but probably would have got on with it a bit better if I had more experience of it.

NEVER press the test button first,this is the last test you carry out, and only if all other tests are satisfactory,

the reason is that the RCD could have 'grown' together, and therefore would not trip in case of a fault, which will show on your tests,

pressing the button will usually mechanically force the RCD to open, thus now allowing it to trip on your tests,

but this would not happen in the real world fault scenario, you have artificially forced the RCD to work by using the button.

also, if on your first test the RCD fails, DONT test it again looking for a better result, the poor chap on the other end of a live cable wont get another chance.......

" if on your first test the RCD fails, DONT test it again looking for a better result, the poor chap on the other end of a live cable wont get another chance....... "

THATS THE BEST ADVICE I HAVE HEARD IN A LONG TIME ....

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scoobs are the little star in the bottom left of the post.