Adiabatic Lecture.

That's an interesting picture. The N bar looks to be well insulated from the case, but the L bar looks suspiciously like a re-purposed PE bar so I wonder how well it's insulated from the metallic encosure. (It might be nice to see some shielding on it was well, but probably not a requirement).

   - Andy.

Freshly taken yesterdayAJ. Imagine working on a Saturday at my time of life! Periodic inspection on a church hall. Thankfully nowadays I always have a younger chap with me to do the frustrating stuff like remove covers of this adapted SquareD board. He also removed a Perspex screen that covered the re-purposed earth bar. That could easily have caught out even an old hand like me. 
I need to dig a little deeper to get a grip on the Im and IdeltaM issue. In this case, Im is exceeded by at least twice the stated value on the RCD but I am unsure what that means practically. The DNO fuse is the upstream device which will clear a 2KA fault in way less than 0.1s but quite how that relates to the stated Im value, I am not clear.

Freshly taken yesterdayAJ. Imagine working on a Saturday at my time of life! Periodic inspection on a church hall. Thankfully nowadays I always have a younger chap with me to do the frustrating stuff like remove covers of this adapted SquareD board. He also removed a Perspex screen that covered the re-purposed earth bar. That could easily have caught out even an old hand like me. 
I need to dig a little deeper to get a grip on the Im and IdeltaM issue. In this case, Im is exceeded by at least twice the stated value on the RCD but I am unsure what that means practically. The DNO fuse is the upstream device which will clear a 2KA fault in way less than 0.1s but quite how that relates to the stated Im value, I am not clear.