# Annex B: Wiring Recommendations
This chapter is incomplete - still being written/defined.
This makes recommendations for wiring devices in an Open DC Grid. These recommendations are not formally part of the standard.
# Critical Use Cases
To be checked against the grid standard.
# Separate ground path via audio or USB connection
Phone connected to one nanogrid controller, sound system to another. An audio / USB cable connects both devices.
# Multiple inverters connected in different locations to public grid
Are inverters always galvanically isolated? If not, does it create issues in the grid?
# Different grounding of connected existing SHS
Typical PWM charge controllers are grounded at positive terminal (if grounded at all). MPPT charge controllers might be grounded at negative terminal. What happens if batteries of both of these systems are connected to the nanogrid?