Re: Sun 3/XXX 240v power supply — switch to 115v — is it possible?

[Tony Duell]

On Mon, Mar 18, 2019 at 2:59 AM Earl Baugh via cctalk
<cctalk at classiccmp.org> wrote:
>
> Howdy,
>
> I’ve recently gotten a second Sun 3/Xxx 3 slot VME chassis, however the
> power supply is a EU version, 240v. I know on a number of “newer” power
> supplies there is a switch to go from 240 to 115.  I’ve taken this one
> apart ( at least to the point where it comes off the bottom of the VME
> chassis — but left the thick cables still connected. )  I haven’t found any
> switch or any indication that it can switch.  Googling and looking at the
> FEH hasn’t yielded any info either.
>
> Anybody know if it’s possible to switch this type of PS?

The power supply was almost certainly not made by Sun. Are there any
markings/makers name on it? Can you provide a picutre of the PSU board?

Look for a jumper wire, soldered at one end and with a single socket
on the other that can be fitted to one of 2 pins on the PCB. Pins labelled
'115' and '230' for example.

Or a pair of terminals on the connector where the mains cable comes in to
the PCB marked 'link for 115V'

But before you go too far, look at the mains smoothing capacitors. If there
are pair, each rated at around 200V, then it is likely it can be
converted. If there's
just one rated at around 400V then it is likely it's 230V only.

-tony