Electronics International VA-1A-50 Volt-Ammeter, For 50A External Shunt
The Electronics International VA-1A vs VA-1A-xxIn order to accurately monitor amps in an aircraft, a voltammeter must have a shunt through which aircraft current flows. This shunt is built into the VA-1A, meaning you do not have to purchase a shunt with the VA-1A. The VA1-XX (where "XX " is the value of the shunt), on the other hand, must be connected to an external shunt. Be sure to specify what your shunt value is when ordering. If you aren't certain, download "Determining Your Shunt Value" for steps on how to locate what shunt you have installed on your aircraft.
Certification: The VA1 is a Primary Replacement, FAA STC'd instrument.
Not only does the VA1-XX provide pilots with precision voltage (to .1 volts) and Amps (to .1 Amps), but it keeps a watchful eye on the electrical system. The system have a "Discharge" light for low voltage situations, as well as a "High Voltage" warning light for over-voltage situations.
The systems also come complete with an external warning line that can be attached to a warning device, such as an Electronics International AL-1 Warning Light, AV-17 Voice Annunciator or ATG-1 Tone Generator, or myriad other warning devices.
Discharge Warning Light
For a 12 volt system, the light will be on when bus voltage falls below 12.8 volts (+/- .2 volts). For a 24 volt system, the light will be on when the bus voltage falls below 25.6 volts (+/- .4 volts). The voltage signal is picked up on the red power lead to the instrument.
High Volts Light
For a 12 volt system, the light will be on when the bus voltage exceeds 15.4 volts (+/- .3 volts). For a 24 volt system, the light will be on when the bus voltage exceeds 30.8 volts (+/- .6 volts). The voltage signal is picked up on the red power lead to the instrument.
External Warning Line
The VA1-XX has an external warning line that activates during a "High Volts" or "Discharge " scenario. The line is normally open, but when activated, it pulls to ground. You can hook the external warning line to any Electronics International warning device, such as an Al-1 warning light, AP-7 Annunciator Panel, ATG-1 Tone Generator or the AV-17 Voice Annunciator.
12/24 Volt Switch
A selector switch is located on the back of each VA instrument, which allows the instrument to be configured for either a 12 volt system or 24 volt system.
Kit Includes: (VA-1A or VA-1A-XX) Instrument, Wire Harness, Installation and Operating Instructions.
Size (H x W x D): 2.5" x 2.5" x 2.5," with a 2.25" Bezel
Weight: Instrument - 9 oz.; S-50 Shunt - 3 oz.; S-300 Shunt - 12 oz.
Power Requirements: 7.0 to 40 Volts, 2/10 Amp
Display: Viewable in direct sunlight, with dimmable 12 and 24 volt backlight control lines.
Accuracy: 1% of reading +/- one count.
Resolution: VA1-XX (60 Amps and below for "XX") resolve amperage to .1 amps. VA1-XX (above 60 for "XX") resolve to 1 amps. All units resolve voltage to .1 volts.
VA1-XX Configuration: This unit must be matched to the aircraft's external shunt. The shunt value is determined by how many amps must pass through the external shunt in order to acheive a 50mV drop across the shunt leads (i.e., 100 amp, 50mV external shunt would be matched to a VA-1A-100, a 70 amp, 50mV external shunt would be matched to a VA1-70, etc...).