Interesting video on testing type "A"'s RCBO and issues with MFT 's

[Lister1987]

Device standards should be dictating testing regimes, they don't so there is your route problem, OEM/Testers should be ensuring they test to the same standards otherwise there is no unified approach, it's that "It's a 6, not it's a 9" argument all over again.

 

[SparkySy]

Trouble is that then we would probably end up having to buy a copy of the manufacturer standard as well as the BBB on site guide and appendicitis and that's getting expensive! Or (and I'll try not to laugh while typing this) the manufacturer standard should be free to anyone with an interest!

 

[Markyd]

Yep the Megger man just came across as someone punting testers

 

[SparkySy]

but the megger man also said that their testing standard had wide tolerances compared to the manufacturer standard and that their testers although boasting they can test all types of RCD is greatly overstated, aaaannnddd that we only need to test the AC part of the trip so don't really need all the other fancy stuff they have sold us! I can still use my trusty Mft1552 and didn't really need to buy a new 1741+ at all?

 

[WallaceP]

only needing to test the ac part is crazy, unless it just to proven the mechanism works? at that point just use the test button and hope it will disconnect the same way we are hoping it will disconnect in a 'type a' fault

 

[loz2754]

only needing to test the ac part is crazy, unless it just to proven the mechanism works? at that point just use the test button and hope it will disconnect the same way we are hoping it will disconnect in a 'type a' fault

I think the point was that the only test that we can record results for is the AC test, as that's the only table in BS7671 that is available to compare with.
Then we need to do the test again with the instrument set for type A,B, or F. Just to show that it will trip.