Grounding question...

[alank2]

Hi,

So I've got this box I'm using for a CNC controller.  It is aluminum and I've got 120V (North America) coming into via a 3 conductor plug.  The chassis is connected to the AC ground.  The neutral goes to a 48V switching power supply.  The hot goes through a fuse then through a switch to the switching power supply.  The neutral-chassis and hot-chassis are open on my meter, but the ground-chassis is short (switching power supply is mounted to the aluminum case directly).  All of this is fine so far, right?

The switching supply is 48V DC has a V+ and V-.  With nothing connected to the V-, it is also open to the chassis, but it ends up getting tied to ground as well because the controller I am using (Geckodrive G540) is mounted directly to the aluminum chassis and obviously its metal case is grounded to the V-.  Is it ok that the V- gets connected to chassis ground?  Is this how DC devices in a metal chassis are normally done?

Thanks,

Alan

[ejeffrey]

Yes, that is the normal way you would configure electronics in a metal chassis.