The manual is out of date. The current revision (B0) boards don't care. I've got a lot of documentation work to catch up on starting right after the Base3 starts shipping. The documentation changes are pretty much all things like this which just make things easier for people instead of things which they *have* to do differently.
The only thing which needs positive power is the old-style canopy sync board, since canopy sync pretty much requires positive power to operate. The return connection on each input is tied together and should be the grounded conductor, if you are grounding a site at all. If you're doing the DC to DC output thing, your -48VDC input should be hooked to the rackinjector such that the -48VDC is on the Vin pin and the return (or + in this case) is on the return. On the DC - DC converters, you tie the - output of each converter to this same point (the +/return on the -48VDC), and then you end up with +24VDC or +48VDC. So the +output goes to Vin and the - output goes to return, and the 'ground' side of everything else. On Wed, Feb 19, 2020 at 11:04 AM Adam Moffett <dmmoff...@gmail.com> wrote: > From the manual: > > "Important: At least one of the power sources must be of positive > polarity – the current revision of the RackInjector control board needs > at least one positive voltage in order to operate. If multiple positive > power sources are available, it will pull power from the input with the > highest voltage." > > Should I take that to mean a negative terminal needs to connect to > ground for some reason? > > I intend to connect a rectifier (-48V) and Meanwell RSD converters to > other voltages. The RSD's don't have a ground reference on the output > side if I recall correctly. I can add a connection from neg to ground > on the 24V converter, but is that really what they mean by positive > polarity? > > > > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > -- - Forrest
-- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
