New CNC Mill on the horizon

[fvfdrums]

Right we are wiring up the psu. Transformer wired correctly giving 52 Vac. Connected to the Bridge rec at correct terminals. Output from the rectifier on the dc terminals is 45v ?? Shouldn't this be 70ish? Do we have a broken rectifier?

[Jonathan]

Have you put the capacitor(s) on the output of the rectifier? If not then that reading seems about right, as the meter is reading the rectified AC waveform, not a smooth DC output.

[fvfdrums]

Thanks Jonathan,

so we have now connected the caps up to the BR, on powering up to check what voltage we were getting instead of even getting there we got a huge amount of humming and some extreme heat through the negative cable coming from the BR so immediately turned it off.

any ideas what could be going on / we are doing wrong?

we have checked that it is definitely the +ve of the BR going to the +ve on the caps and the same for the -ve.

does there need to be a load on the PSU before we power it up?

[fvfdrums]

scratch that - problem solved, 68/69 Vdc now :)