100mA RCD TT Question

[John-]

I am replacing a TP isolator for a 4 pole 100mA RCD.
The existing install is such with incoming cables at the top snd tales to the dis boards at the bottom. Am I right in thinking that for this application orientation of in and out on the RCD will not matter? Checking manufacturers details and there is no guidance for connections nor orientation. The conductors are not long enough to be revearsed so was going install with supply in at the top and load out on the bottom.

thoughts?
Thanks

john

 

[telectrix]

most RCDs in use have in at the top and out at the bottom. what's the problem?

 

[pc1966]

I asked Hager the same as they provide SFA information on supply/load orientation, and they eventually confirmed it did not matter (at least for the models I inquired about).

If in doubt then I would go with the orientation they have in the same brand of CU, which as @telectrix says is conventionally the load busbar at the bottom, supply top.

 

[John-]

Thanks. Obviously if i get any issues during testing then obviously all bets are off!

 

[R-fur]

Some times the test button wont work if the RCD is wired the wrong way round.

 

[DefyG]

If stand alone quite often in at the top but if used as a switch disconnector in a TPN DB then 'in' is at the bottom. Cant imaging the guts (electronics) are any different either way up!

 

[pc1966]

Cant imaging the guts (electronics) are any different either way up!

Up to the point of tripping, no.

But worst-case is they RCD depends on the contact's opening to stop the trip coil current after it fires and if wired the wrong way round simply roasts it as the "output" never stops!