05 system isolation - wildekek/rdtech-firmware-unisoft GitHub Wiki

System Isolation

6 4. Nomenclature & Formatting ● Items in double quotes (“ ”) refer to Physical buttons. ○ The Font will also be changed to the one used on this line. ● Items in single quotes (‘ ‘) refer to unit settings or modes. ● CC mode - Unit will attempt to maintain a Constant Current (maximum) output, adjusting the Voltage output as required. ● CV mode - Unit will attempt to maintain a Constant Voltage (maximum) output, as long as the load’s current (Amps) demands are below the ‘I-Set’ Value. ● Protection Mode - Unit has sensed a value exceeding its protection setting. (eg OVP, OCP, etc) ○ Output will be immediately turned OFF when entering this mode. ● Normal Operating Mode - Unit is not currently experiencing any errors and is not in a protection mode. ● Graph Display mode - Any screen showing values graphically via a graph, rather than text. ● Primary Power Supply - The Power Supply (PS) that supplies DC power to the RD60xx Unit. ○ MAXIMUM Voltage In = 70V DC. DO NOT EXCEED 5. System Isolation Assuming your particular Primary Power Supply output is isolated from the AC mains' protective ground (i.e. green with yellow stripe insulated wire, or bare copper wire; also known as protective earth) then the 3 output terminals on the front of the RD60xx units will also be isolated. This makes the RD60xx unit a floating supply. Some confusion may arise due to Ruideng's choice of a green terminal as an alternate "+" terminal for battery charging, since many other power supplies choose to have a green "third" terminal on the front of their units connected to the AC mains protective ground. The USB port on the front of the RD60xx, is galvanically isolated from the rest of the unit. The isolation integrated circuit claims 3000 Volts AC rms isolation (UL certificate number: E494497). Even without dangerous voltages being involved, it is still possible to have unexpected current flows through the negative terminal (ground) if the USB port were not isolated. For example, a laptop connected to an external monitor could effectively be tied to the AC mains' protective ground (via the monitor). If a device that was protective ground referenced were connected, by a USB cable, between the laptop and a NON-isolated USB port the device could cause a protection trip or worse. Therefore, the USB port of the RD60xx unit being isolated is an important safety feature.