Power supply question

[PsyKotyk]

I have a power supply (see attachments). I was attempting to use the two red wires to create my 52VDC, but I found I kept tripping the breaker. Turns out the common on the red coil (brown) is the same as chassis ground, and my circuit boards have their logical ground attached to chassis ground. This had me sinking 24V to ground through the boards (fortunately I have HEAVY grounding planes on them).

I'm trying to think of a combination that will get me my 40VAC and still have logical ground == chassis ground. I have no problem adding more bridge rectifiers if needed.

My first thought was to connect brown on the primary side to ... well maybe just disconnect it and let it float up. Seems incorrect though. There is a 2 ohm resistance between brown on the primary to brown on the secondary coils, so I assume they are not directly connected.

My second thought was to bring the blue coil into it, and chain the two together.

Grateful for any ideas.

P.S. If you're interested in this power supply, the place I got it from has about 4 or 5 more going for $35CDN each. The fuse rating is 6A, so I think it's good for quite a bit on the outputs. The place is called Computer Recyclers here in Ottawa, ON.

[Al_The_Man]

What do you mean by 'Brown on the primary side'? I assume there is no connection electrically with the primary, if so the brown is electrically on the Secondary side, and if grounded internally then you cannot use a DC ground reference, as one diode of the bridge would be short circuited.
You should however, be able to parallel the two secondaries for double capacity, providing they are very close to each other, voltage wise.
It would also require them to be phased correctly before paralleling.
If you can find the ground connection of the brown conductors, you may be able to isolate it, and then ground the DC -ve.
Al.

[PsyKotyk]

I disconnected the brown wire that was coming out on the primary side, and that did the trick. I think it might have just been directly connected to the brown wires on the secondaries. If I start using the blue coil, I might need to change things, as I'm not sure the two commons are compatible.

Thanks for the reply Al. I'm still trying to understand it all.