We recently bought two used Rittal PDUs (7979.216) which were still configured by the previous owner. Neither the web interface nor SSH was accessible, as the admin credentials were unknown and the default credentials didn’t work. Power-cycling the device or pressing the reset button once did not change anything.

I asked the Rittal technical support how to get the devices back to factory defaults and received a pretty simple answer.

Procedure

  1. Press and hold the upper left button (1) next to the display.
  2. While holding it, briefly press the hidden reset button (2) with a paperclip or similar.
  3. Keep holding the upper button until the status LED starts blinking white.
  4. Release the button.

The PDU now resets to the last working firmware version and returns to its factory configuration. Afterwards, the default credentials from the manual work again.

Output Sockets Stay Powered

The 7979.216 can measure the input feed, but it can’t switch the output sockets or the supply voltage. Therefore, the outlets stay powered during the whole procedure and connected equipment is not affected.

If the Reset Doesn’t Work

If a local reset is not possible, the PDU has to be sent back through the Rittal Service department. Costs and turnaround time need to be agreed upon with them directly.