110v tranny and rcd's

markythesparky · Feb 9, 2014

This has probably been asked on here before but at the risk of being boring I shall ask again. Why do some 110v transformers trip rcd's when there is no sign of any fault in the supply flex or plug top?

Knobhead · Feb 9, 2014

Have you tested the transformer primary windings to earth?

telectrix · Feb 9, 2014

are you sure it's RCD tripping? if it's a RCBO, it's more likely that the inruch of the tranny has tripped the OC part of the RCBO.

i=p/u · Feb 9, 2014

I've noticed at times peoples equipment or trannys tripping rcds. As tony says test primary side to earth. Could this be done from plug top just..? Or am I talking ...beep

Knobhead · Feb 10, 2014

Easiest place to test.

Tel makes a good point as well.

Guest111 · Feb 10, 2014

They are a funny thing,my 3.3 kva used to trip a lot on some houses but never on others.

Guest55 · Feb 10, 2014

yeah , we all love a good tranny.......

oh ! that kind of tranny.
oops.
;-)

Darkwood · Feb 10, 2014

phil d said:
They are a funny thing,my 3.3 kva used to trip a lot on some houses but never on others.

Depends on the topography of the house if you high up a hill the electric has to pump uphill this slows it down and lessens the inrush

A few variables to consider ...:-
-The type of mcb
-The measured voltage at the house
-Network load

All play a role in what size inrush can be achieved before the fields build up..