Oceanic Systems AC Monitor w/ 200A Slg Phase AC Current - 3420Oceanic Systems AC Monitor w 200A Slg Phase AC Current 3420 The Oceanic Systems 3420 AC Monitor accurately measures the AC voltage, AC current and AC Frequency and reports them over the NMEA2000 network. The unit can be used for Single Phase, Bi Phase and Three Phase systems and is suitable for measuring AC sources such as Shore Power, Generators and Invertors. It can also measure the voltage and frequency on AC Bus Bar Systems. The voltage sensing is