That governor looks like a dumb waiter type. No electrical trip as it appears to only activate the instantaneous safety gear. The tiller rope attached to the governor rope will trigger the action. Either way unless you happen to get the pump unit to massively over speed I cant see how it will trigger an overspeed situation. You may be able to test that the action works by lifting the roller high enough by another means ie an attached small rope linkage, whilst the lift is moving.
