Pro-360 Locknut Service Bulletin

We’ve recently had two Pro-360s returned for repair that showed signs of incorrect installation. The locknuts securing the main terminal posts to the PCB had been loosened and this resulted in short circuits destroying both the mosfets and the control board.

This picture shows the issues…

Points to note are:

1] Never loosen the locknuts, these are set during production and do not need to be undone.

2] If a locknut does come undone, and if the terminal stud rotates in the bus bar, the stud may cut through the pink insulation strip between the bus bar and the heatsink creating a short circuit.

3] If you find that a locknut has become loose, it is ok to re-tighten it [to 6Nm], BUT you MUST use a multi-meter to check to see if any connection has been created between the terminal posts and the heatsink. If this has occurred, loosen the locknuts and wind the stud out of the bus bar until the connection disappears. Then re-tighten the locknut and re-check for connectivity.

4] If you use a Pro-360, we recommend disconnecting the power, removing the cover and inspecting all the locknuts for security.