Main breaker tripping.
By Erik Davidson
10 June, 2020

What’s going on?

If the main breaker has tripped or keep on tripping there are a few things you need to investigate to understand what’s causing the issue.

The main breaker can trip for a few reasons:

  1. The emergency stop has been activated.
  2. The neutral protection system been triggered.
  3. The main breaker has tripped itself due to overload.
  4. The test button on the main breaker has been pushed.

If the main breaker trip immediately after you turn it on and continue to do this repeatedly, the first thing you should check is if the Emergency stop is activated, twist the emergency stop clockwise to reset it to normal position.

If the behavior persists, the most likely cause is that the Neutral protection system has activated due to a missing or weak neutral connection. The best way to see if the neutral protection system has activated is the be connected to the remote supervision system where this will be indicated in the unit status block. The supervision system will run for about 10 minutes on battery back-up even if the unit is without power.

Check the neutral to make sure that you have a proper connection.

Insufficient wire gauge on the neutral can cause the voltage between neutral and earth to rise and trip the protection system, make sure you are using proper supply wires, remember that the neutral can be subjected to a very high current if the phases are carrying very uneven loads.

The main breakers on the smartPDU, C72tv and the C-qaud all have current limiting functionality that can cause the breaker to trip if there is any load that goes out of the selected range on the main breaker. The C12 and the C24 uses a disconnector without this function so this does not apply to them.

Check that the main breaker settings are relevant for the conditions at hand.

If you don’t have knowledge are solid information on what the settings should be, return the settings to the default mode.

Click on the buttons for the main breaker default settings: