What methods are employed for measuring a 680 VDC bus to provide a 0-4 VDC feedback signal to a microcontroller ADC. The DC bus consists of 2- 450 VDC capacitors connected in series. I had initially considered a voltage divider measuring from the capacitor center tap to positive, but this would require bonding the center tap to GND. The HV DC bus normally floats, would it be acceptable to ground the center tap of the DC bus to GND and likewise the GND reference of the ADC?