MASSO Documentation

MASSO G3 Ground Loop Damage and Fixing

If a ground loop is formed on the MASSO G3 controller then the below components are expected to get damaged due to high current flow.


WARNING: MASSO G3 Touch controller when mounted on a machine with a metallic arm may form a grounding loop. Caution must be taken to avoid the ground loop and the below steps can help prevent this issue.





Examples of damage caused by ground loops





Preventing ground loops

On any machine setup, multiple ground loops can happen where long cables are connecting equipment. Some examples:

  • Ground wires between controller and motor drives.
  • VGA screen ground wire between controller and VGA monitor.
  • Ground wire between external powered USB HUB. NOTE: If the USB HUB is only powered by the controller's USB port then a ground loop is not formed.
  • If a long USB cable is used from the controller and the other side of the USB socket's body touches another ground such as the body of a machine.
  • If the controller's ground pin is connected to the frame of the machine. This is can happen on the MASSO G3 Touch controller via the rear mounting plate.


The best way to avoid ground loops is to make sure that the entire machine is only grounded at one point only. The same applies to when wiring the machine frame and other electronics. Ground loops can be formed in a lot of different ways and are hard to document but having this understanding can help plan the wiring of machines and troubleshooting.




WARNING: MASSO G3 Touch controller when mounted on a machine with a metallic arm may form a grounding loop. Caution must be taken to avoid the ground loop and the below steps can help prevent this issue.


On the MASSO G3 Touch controller if the ground loop from the machine frame can not be avoided then the controller electronics can be isolated from the enclosure rear mounting plate by following the below steps.


WARNING: Even after following the below steps the user must check that the ground loop is not formed by any other wiring to the unit.





The metal HEX spacer next to the USB socket connects the controller boards USB socket ground to the mounting plate and if the mounting plate will be mounted to the body of the machine which might result in a ground loop then this spacer can be removed and replaced with a plastic/nylon spacer or not installed.


CAUTION: When removing the HEX spacers caution must be taken not to damage any small components on the circuit board. Also, check for any small metal cuttings that might drop on the circuit board.








Next with a multimeter check the continuity between the rear metal plate and the USB sockets. There should not be any continuity between these two points.










Repairing

If the unit has been damaged due to a ground loop and damage can be seen on the marked components then the following steps can be followed.


If ONLY the below marked components are damaged, then these damaged components can be simply removed and the two points can be joined together with some solder. Removing these damaged components and replacing with solder joints will not affect the functionality of the unit.



WARNING: If the ground loop issue is not fixed prior to removing the damaged components and making solder joints then the ground loop might damage the unit beyond repair.