Shower tripping rcd

[Johnnyryan]

Hi guys. I've been called to a house to sort a shower. They have two showers on priority switching all wired correctly. The priority shower is tripping the rcd.

I switched the showers around(same model) but it tripped again. I ran the shower on full twice for 10-20mins and no trip.

I did notice the contactor was buzzing pretty bad when shower was running. Its a 40A. I'd be more inclined to use a 63A as the shower draws close to 40A.

So my question: is it the contactor is gone and tripping the rcd or the fact that the contactor is running so close to it's rated amperage??? Can't see why it would trip the rcd and not the mcb on an overload condition. All hager by the way.

Thanks!!

 

[Doc Hudson]

Welcome to the forum. The first questions I would be looking at before considering contactors is what are the test results for the cable, continuity IR and RCD trip times, ramp test etc..

Doc H.

 

[kme]

Concur with the doc.

To quote Short Circuit`s Johnny 5......

"Need MORE input"