The 50mV/500A Shunt can be used with several popular Amp-Hour Meters, such as Xantrex Link 10 or TM-500A, or Trimetric 2020, the Pentametric Battery Monitor or the new outback Power FLEXnet DC.
How a shunt works:
A shunt is necessary in order to measure amps and amp-hours with these Amp-Hour Meters. A shunt is an accurate, very low resistance resistor which is placed ‘in line’ with the wire carrying the current to be measured. This can the battery cables to the Inverter or the PV IN or PV Out of a Charge Controller. When current flows through the shunt, a small voltage is developed across the shunt which is proportional to the current flow. The Amp-Hour Meter battery monitor accurately measures this very low voltage and converts it to the ‘amps’ reading on the meter. The resistance, which is the ratio between the voltage across the shunt and the current flowing through it, is a constant for any particular shunt–and is one of its important parameters. For most substances, resistance is usually described in ‘ohms’, however for some reason shunts are described by the voltage drop that occurs with a certain current: for example: ’50 millivolts at 500 amperes.’ However the meter only cares about the ratio-which is the resistance–so a 500Amp/50 millivolt shunt is equivalent, to a 250Amp/25 millivolt shunt. They both have a resistance of 0.1 milliohm, or one ten thousandth of an ohm.
Keep in mind, many DC Disconnect Boxes already have or provide a Shunt of their own. Some are exactly the same dimensions as this shunt, some are not. All 500A/50mV are electrically the same, so you can use the shunt that came with the DC Disconnect if it is also a 500A/50mV Shunt.