The VA-1A and the VA-1A-XX both have shunts. By measuring the voltage drop across a shunt, the VA-1A and VA-1A-XX can
determine how much amperage is being loaded on the aircraft's battery or alternater/generator.
The VA-1A has an internal shunt, and the VA-1A-XX requires an external shunt. For the VA-1A-XX, the "XX" equals the
value of the shunt. To determine the value of your aircraft's shunt, visit the Downloads section of the VA-1A and download the
sheet entitled "Shunt Value." The VA-1A-XX can be custom built to match your aircraft's existing shunt.
Most people who are replacing their existing Voltammeter will replace it with a similar type (internal or external).
Internally shunted systems generally have large lugs at the back of the instrument (this is part of the internal shunt), while
externally shunted instruments have small wires that leave the back of the instrument.
Used with the VA-1A-50.
For amperage loads up to 100 Amps.
Used with the VA-1A-300.
For amperage loads up to 300 Amps
The RSVA-3 allows pilots to switch between three shunts for a twin engine application. The switch will select between
Left Alternator (or Gen), Right Alternator (or Gen), and Battery shunts. This allows the pilot of a twin engine aircraft
to monitor all loads on the aircraft system with only one instrument.
Shunts are not included in the RSVA-3 price and must be purchased seperately.