What is the voltage of C16 circuit? Power supplies input voltage?
Are you using any sort of extension cord to get power to the miners?
What are the cards?
Voltage is european 230V, if that is what you mean.
Extension cord Brennenstuhl Premium-Line 16A/3600W. (but tried with another extension -> the same situation).
To this 2 miners are connected, both with 2 PSUs, so 4 wires in total for the extension.
Cards are Asus Dual OC RX580 8GB.