The Sterling Power Alternator Protection Device (APD) is designed and intended to protect a 12V alternator from an open circuit or load dump. It is essentially a high power TVS diode unit that prevents damaging voltage transients that would otherwise blow the alternator diodes. Any boat that has an alternator circuit wired through a battery switch can benefit from the Sterling APD.
The Sterling APD can also be used as a transient suppressor for your DC panel or other sensitive DC circuit. It is far less costly than a re-wire and is a good insurance policy to minimize the risk of voltage transient damage..