Problem with VMB3PS power supply

Just took delivery of a few Velbus bits to play with and have a go at programming in Visual Studio 2008, thats giving me issues… but first and more importantly…

I have got an issue with the power supply VMB3PS, it is powered from a Velbus transformer VMBTR1, however when connected up as described in the manual as a single output transformer… positive in to terminal A and negative into terminal F and terminals B and C bridged and then D and E bridged…

I get +20 volts at the output !

I get the right lights on, but do they just show power, or correct voltage and polarity ?

What am i missing ?


It is normal to measure 20V at no load.

Ok, I was worried this had a detrimental effect on the USB interface !
Many thanks