Balanced Power Supply problems - any ideas?

[worrasf]

My new balanced power supply arrived this one(http://www.airlinktransformers.com/transformer/bp3120-bp3120-balanced-power-supply.asp) and is all connected up.

The problem is it keeps tripping the RCD (Niglon 32/30) in the consumer unit. I have this on a dedicated ring for just the hifi. If just the supply to the BPS is connected no problem but when the load is connected to the BPS the RCD trips (with all wall sockets empty). However, if I disconnect the earth wire on the load side then all is fine and get full power to my hifi sockets. I have temporarily connected the earth tag on my mains distribution block (Merlin) to ground to ensure that there is an earth point (I did not have this connected at the same time as having the load earth wire connected in the BPS).

Any ideas how I can keep the BPS wired correctly without the RCD tripping?

Steve

[Reid Malenfant]

Let me see if i have this straight :scratch: When the balanced transformer is connected & nothing is connected to it's output all is well :) However, as soon as you connect your wall sockets to the transformer output (even if nothing is plugged into the wall sockets) then the RCD trips?

Is that right? :confused:

[worrasf]

Hi Mark - no not quite. Even with nothing connected to the sockets if I connect the output side earth wire inside the BPS then the RCD trips. If I do not connect the output side earth wire inside the BPS then all is fine and I get power to the sockets and can run the HiFi - it seems to be a problem with the output side earth wire. Maybe its the way the earthing is wired in the sockets I dont know - very strange.
Steve

[Welder]

Is your dedicated mains earth connected to the grid or a separate earth stake?

[Reid Malenfant]

Hi Mark - no not quite. Even with nothing connected to the sockets if I connect the output side earth wire inside the BPS then the RCD trips. If I do not connect the output side earth wire inside the BPS then all is fine and I get power to the sockets and can run the HiFi - it seems to be a problem with the output side earth wire. Maybe its the way the earthing is wired in the sockets I dont know - very strange.
Steve
Getting there... Now if you disconnect anything connected to the secondary of the transformer & have the secondary earth connected to mains earth does the RCD trip then?

It sounds like you have some kind of problem with the wiring that connects to the transformer output? :scratch:

[worrasf]

Yes.
I've found that if I disconnect the 2 earth leads going into and coming out of the first mains socket on the ring then the RCD doesnt not trip - sounds like a problem with the wiring after this socket - its a brand new mains installed by a qualified electrician.
Steve

[worrasf]

Is your dedicated mains earth connected to the grid or a separate earth stake?

To the grid - is that the problem?
Steve

[Reid Malenfant]

Oh dear, you should have let an amateur do it :lol:

I have a feeling that for some reason you have some kind of circuit between Earth & Neutral which is forcing current to flow to Earth. Test it with a multimeter & see if you have one that is ;)

This wouldn't be too much of a problem with standard mains as Earth & Neutral are tied back at the substation, but because it's now balanced it's messing it right up...

[worrasf]

Hi Mark I think that's exactly what's happening - just tested the wires going into the back of the second (last socket) all very strange.
Firstly, both cables are live! I dont understand that at I thought one would be coming in (live) and one going back to the consumer unit (only live when other cable was connected to it in socket)
Secondly there is a connection on my multimeter between earth and neutral on both cables.
This is bloody odd.

Steve

[Reid Malenfant]

Ohhh, it's not earth leakage that is causing the RCD to trip, it's shorting the secondary & drawing too much current :eek: :doh:

You need to get that wiring sorted, by an amateur going on your previous experiences :eyebrows:

[worrasf]

Sorted it :)

Just disconnected one of the earth leads at the back of the second socket and no RCD trips. I've made sure that the sole earth lead connected to the socket is indeed going to earth with a multimeter so unless I have missed something I think that's it but I'm not holding my breath.

If all continues well I'll check out how the BPS performs later in the weekend - always assuming there is no loud bang and a smell of burning :eek:

Steve

[Welder]

No, not a problem really. It’s just that when I had dedicated mains at my old place it took me some time to get a decent earth using a ground spike so I was going to be sensible for once and say don’t mess about with it until you’re satisfied current runs to ground. I got a fairly nasty jolt messing about with the last set up.

[Reid Malenfant]

Sorted it :)

Just disconnected one of the earth leads at the back of the second socket and no RCD trips. I've made sure that the sole earth lead connected to the socket is indeed going to earth with a multimeter so unless I have missed something I think that's it but I'm not holding my breath.
Good news :) I'd check that you have approximately 120V of AC on both Live & Neutral relative to earth & 240V accross from Live to Neutral & you are good to go :cool:

[worrasf]

Something definitely not right here Mark - I thought it was to good to be true :eyebrows:

240v across live and neutral
BUT 240v live to earth and 0v neutral to earth :steam:

Doesn't look balanced to me :mental:

Steve

[Reid Malenfant]

Have you reconnected the Earth on the secondary of the transformer to mains Earth?

[worrasf]

Sometimes my own stupidity amazes me :doh:

That's exactly what I did wrong.

All sorted now - 240V across live/neutral

120v across live/earth & neutral earth.

I am really grateful for your help Mark - esp previous post.

Thanks
Steve

[Reid Malenfant]

No worries, i'm pleased all is now as it should be :) Might as well help out where i can, i'm sure that anyone else on here would do the very same if they could lend a hand ;)