How the controllers can go bad?
Wrong connections are major reason for damaging controller ( of any make ). As controller handles high line voltages it is dangerous to connect wires at wrong terminals. All controllers are protected against spikes, high voltages transients. There are some instances of burning off terminal of back panel. This happens in abnormal cases when thyristor of the machine shorts, due to some external reasons. If the controller is properly isolated by “isolation transformer ” ; most of the malfunctions can be eliminated. This isolation transformer provides 220V for control power of the controller.
