I am in the process of powering the subject unit and start the programing. As soon as I install the connectors, it powers up. I assume this is because I have a standby battery. However, I can't figure out how to power it down with the front keys. I don't see anything in the manual and GRT support is at SnF. Can someone help me with this. Do I need to disconnect the standby battery until I get it programmed? Thanks for the help.
Van's Air Force
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GRT Sport/Horizon 10.1
- Thread starter ten4teg
- Start date
moosepileit
Well Known Member
Switches fail, you install them in the plane for each power source.
BH1166
Well Known Member
I have same unit. There is no on off switch /way to use keys to turn it off. You can reboot the already running unit with keys , but no on/off that Im aware of after years of use. Thinking you should have a breaker to it, you can pull it to power disconnect . If unit is on via backup, what toggles it to come on? You sure that is wired correctly? Doesn’t seem so. Seems yours will be on all the time when avionics master is off, snd back turns it back on . If you have made the pin out correctly in the DB connector , plugging it in should not be powering up the unit, if so something seems off about how back is wired? Disconnect your BU battery, get the unit powered up and configure, then go back and review your BU installation.
Canadian_JOY
Well Known Member
Concur with the above statements. GRT EFIS devices are very simple - they are ON when power is ON. (One minor exception is the Mini series with internal battery but that's a totally different kettle of fish.)
If you are powering via both main bus and backup battery then you'll need to rethink how you have made those connections.
I have three GRT EFIS devices in the airplane. Two of them are wired to a backup battery. This backup battery is charged from the main bus.
Schematically power runs from main bus through a breaker and diode to the backup battery. Power then runs from the backup battery through a fusible link to a SPDT switch, then to the Essential Bus. From the Essential bus power flows through individual circuit breakers to the EFIS devices.
Primary power for the EFIS devices comes from individual circuit breakers installed on the main bus.
In day-to-day operation this setup is very simple to operate. Get in the airplane, flip on the ESS BUS switch, the EFIS devices (and EIS) come alive. Go through all the pre-start checklist, flip on the Master switch to energize the Main Bus. The EFIS devices are now powered by the main bus. Crank the engine - if cranking current draws down the main bus the EFIS devices don't even blink because they have access to the ESS Bus power. In the event the main bus goes dead, the EFIS and EIS keep running until the ESS battery depletes.
Hope this helps.
If you are powering via both main bus and backup battery then you'll need to rethink how you have made those connections.
I have three GRT EFIS devices in the airplane. Two of them are wired to a backup battery. This backup battery is charged from the main bus.
Schematically power runs from main bus through a breaker and diode to the backup battery. Power then runs from the backup battery through a fusible link to a SPDT switch, then to the Essential Bus. From the Essential bus power flows through individual circuit breakers to the EFIS devices.
Primary power for the EFIS devices comes from individual circuit breakers installed on the main bus.
In day-to-day operation this setup is very simple to operate. Get in the airplane, flip on the ESS BUS switch, the EFIS devices (and EIS) come alive. Go through all the pre-start checklist, flip on the Master switch to energize the Main Bus. The EFIS devices are now powered by the main bus. Crank the engine - if cranking current draws down the main bus the EFIS devices don't even blink because they have access to the ESS Bus power. In the event the main bus goes dead, the EFIS and EIS keep running until the ESS battery depletes.
Hope this helps.
Thanks for the info. Sounds like I need to put a breaker/switch on the backup power. First time with GRT. Lot of options, but lots of programming.
