Inverter Disconnect Switch with Precharge 2022-04-13

To get the paper, click on the orange button at the top of this page.


This circuit is designed as a disconnect switch that allows the user to pre-charge the inverter capacitors before turning the switch completely on.

26 June 2020 update:

• At request of a forum member I added a circuit design for 48 volts.
  Warning: I have not built/tested the 48 Volt design.
• Added comments on how to build the circuit without the PTC thermistor.

28 July 2020 update

• Expanded on building the circuit without the PTC thermistor. (It is not needed in many (Most?) situations)

8 August 2020 update

• Updated link to PTC in the parts list.

5 October 2020 update

• Added slide showing the connections in the four different switch states. (this helps explain how the circuit works)
• Added label and printing instructions for Perco 8511 switch.

6 October 2020 Update

• Added discussion of Inverter Disconnect vs Battery Disconnect

28 November 2020 Update

• Added assembly picture for building w/o the PTC resistor.