Hi
Anybody know the answer to this?
(1)
The On Site Guide, referring to RCD testing, has two different tripping times.
For BSEN 61008 & 61009 it’s 300mS and BS 4293 it’s 200mS. I have never been able to find the reason why the newer ones are allowed a longer trip time. Surely if 300mS is allowable for one it should be okay for the other, even if originally manufactured to trip within 200mS
The other thing is time delayed ones. For the BSEN it’s stated as 130 to 500mS but the test for the BS it’s stated as 50% of rated time delay plus 200mS to 100% of rated time plus 200mS. What is the “rated time delay”?. It can’t be the 200ms as this is the max trip time, not the rated time delay. It doesn't make sense if you use to 200ms as that is 300mS to 400mS.
(2)
I haven’t yet come across a type B RCD but as my tester is capable I looked up the test in the manual (Megger MFT1700 series).
It says to do a type A first. Then you need 3 leads to do the B and only on times 1.
Okay so far as this suggests that it’s a special test only using smooth DC which was confirmed on doing a search on Google for this test.
The confusing thing, though, is that it states the result is in mA; not mS. No explanation for this.
There is nothing on YouTube about this test, which is surprising.
Hope someone can answer these.
Thanks.
