08-11-2012, 11:09 PM
Certainly the typical 50V dc signalling busbar is anything but straight dc; half wave rectified peaking at around 80V, so there is a large ac component. I don't quite see how it would work out, but perhaps if the component causing the short to earth was on the transformer side of the bridge rectifier then perhaps that short is only "seen" at the busbar for one of the half cycles. thing is that I'd have then expected for that short to be seen on the other side of the busbar during the opposite half cycle.
As Peter says this is interesting and a better understanding of what these filters actually are may help shed light on the matter.
As Peter says this is interesting and a better understanding of what these filters actually are may help shed light on the matter.
(08-11-2012, 07:52 PM)Archie Wrote: Many thanks for the quick reply, the small black filters are mounted on the inside right hand of the transformer NT6631, which I believe each act for all your different bus bar voltages 110bx b120 b50 b24, I believe like you mentioned that they are possibly shorting to the case of the transformer upon where they are mounted. But another colleague of mine mentioned that the B50 showing 25 volts to earth is half wave rectification, I am confused as how that relates if at all.
Any clarification would be greatly received.
PJW