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