mcb testing

[rovers1982]

Work advertised in my area to test faulty mcb's & replacing if necessary, am i right in thinking that Psc & Pefc results measured & results taken & checked against mcb ratings.

 

[Andy™]

testing of MCB's is rarely carried out. they would normally be taken off-site for testing.

only other form of 'testing' i can think of would be to check Zs is low enough that MCB will trip with required time

 

[Andy™]

other thought is this may be for Electrium, checking for their faulty MCB's and replacing as required?

 

[roys]

Last week we did a sample test of 2 MCB's a Type B 10A and a Type C 16A by current injecting at 1xIn and 2xIn. This to to check that they operated in line with the curves in the BRB. It is a long story on why we did this, but needless to say it is not a test we normally do. They both operated OK.

Cheers Steve

 

[m4tty]

Last week we did a sample test of 2 MCB's a Type B 10A and a Type C 16A by current injecting at 1xIn and 2xIn. This to to check that they operated in line with the curves in the BRB. It is a long story on why we did this, but needless to say it is not a test we normally do. They both operated OK. Cheers Steve

What did you use to inject the current ? Just interested in how this is done. And why arnt mcbs checked, as rcds are?

 

[Andy™]

What did you use to inject the current ? Just interested in how this is done. And why arnt mcbs checked, as rcds are?

RCD: upto 500mA req'd (normally only 150mA for most situations).

MCB: potentially thousands of amps

 

[kme]

why arnt mcbs checked, as rcds are?

Because MCBs are only rated for a certain no. of "trips" before they`re considered U/S. Though, as I was discussing with another forum member today, how do you know, when you arrive at a board, how many times a particular MCB has tripped??

 

[Andy™]

you dont.

and whilst were on about it - anyone know how i can test a fuse!?

 

[kme]

put it in series with a 9V battery and lick.......

If you feel a tingle, the fuse is ok :coat

 

[Andy™]

put it in series with a 9V battery and lick.......If you feel a tingle, the fuse is ok :coat

i mean test that it will melt at the required amps & within time?!

someone must know how to do it!

 

[Sidewinder]

Yep but you'll only do it once!



GOT to go to bed now, REALLLLLLLLYYYYYYYYYY!!!!!!!

:good night: :good night: :good night: :good night: :good night: :good night: :good night:

 

[rovers1982]

Thanks for that

Unsure why tests being carried out but it is happening to substantial amount of properties in Roptherham & also agencies are asking for this type of work in Doncaster, Chesterfield, Licoln & S****horpe but work description very vague.

May be able to find out more today.

Thanks All

 

[roys]

What did you use to inject the current ? Just interested in how this is done. And why arnt mcbs checked, as rcds are?

Hi m4tty. We have a current injection set that does up to about 50A. We use it a lot for checking motor overloads. This was a 'one of' checking of MCB's as it is not a common test, because as kme mentioned they are not designed to do loads of tripping. We just had some suspicions about a batch, as it turned out they were OK.

Cheers Steve

 

[Robojin]

[quote name='Andy

 

[Andy™]

I guess that would be a bit like testing matches ; \

or glow sticks

 

[Oracle]

Hi there,

When I worked at Rolls Royce, we tested new MCBs and performed scheduled testing of existing MCBs.

This was many years ago - where we had a custom made injector (testers weren't that common then).

Nowadays there are some decent testers about - but they aren't cheap!

MCCBs/ACBs anyone?

O.