GRT Avionics

Hi folks,

I have a dual electronic ignition and so have a secondary battery to power it. I would like to be able to see that battery's voltage on my engine page. The set up is: EIS 4000, dual HX, VPX. I have a sensor wire going into the VPX so on that page you can see the voltage of the aux battery. On the EFIS screen I have a bar that says EIS voltage, a second one that says EFIS voltage and was able to bring up a bar that says Aux Voltage. The Aux voltage bar reads zero. I am not sure how to get the aux battery voltage to be reflected there. Do I need to run a wire or is there are way to tell the EFIS where to look for this?

Regards,

Michael Wynn
RV 8
KLVK

Michael,

I am also based at LVK, let me know if you would like to get together sometime. It is always easier to answer questions with a wiring diagram in front of you. That being said, I would run a wire from your aux battery to the number 2 power input on the HX. There are then options (see set up manual) to display that voltage in a box on the PFD, or as a bar on the engine page. If wired this way, the HX will draw power from whichever source has a higher voltage. I would wire the aux battery wire thru a pullable CB, so if in a complete failure you need to preserve that aux battery you can pull the breaker and save the power the HX would draw.

Bob

The VP-X Aux battery input is not connected to one of the bar graphs at the moment. It does display a line of text and a digital value in the upper left corner of the VP-X page if you tell the EFIS there is an Aux Battery connected in the SET MENU, Display Unit Maintenance, VP-X Configuration.

If you don't want the HX to ever draw any power, as Bob suggested, it's possible to wire any voltage to one of the EIS Aux or HX Analog inputs with some resistors and configure it as a bar graph.