Forum menu
I have a low voltage pendant light which I believe the 12v DC transformer has failed so I have purchased another one exactly the same rating etc.
The only thing I'm unsure of is the original transformer had one side of the output tied to ground.
I've not been able to find anything about the new transformer that says I either should or shouldn't do this.
Is it normal to tie one side of the output to ground in this situation?
If it has a metal case or parts of it aren't double insulated, then it will be earthed to mains earth so that if a fault develops and the case goes live, it will trip the RCD or blow a fuse.
You only need one earth connection as the box itself can earth both sides for you (not that you really need worry about the 12v side as it won't trip the RCD etc being effectively isolated from the mains by the transformer).
The case is metal and the AC side is earthed.
I got the impression that the earth tie on the output was to 'force' one side of the output to 0v as there are no polarities on the output.
The case is metal and the AC side is earthed.
All good.
I wouldn't worry about the 12v side. When they designed it they will have evaluated the failure modes and made a decision about whether to earth or let the DC side float. Either way, if it's needs earthing it will be earthed internally.