BeechTalk - BT - New CE-500 owner joined the club

Username Protected · **Posted:** 12 Apr 2023, 10:31

Username Protected wrote:

So what happens when it goes lower than 9 or 11 V? I was raised not to taxi before the flags pulled, etc, but I don’t understand how a G600 is powered on the battery bus vs any risk with the avionics bus on when starting?

My assumption was that it would shut off until the voltage came back - effectively it would reboot. This would be annoying as I would have to reset my V speeds, re-transfer my flight plan from Foreflight, etc but wouldn't be the end of the world. But I'm glad to know that my voltage doesn't sag enough to cause it.

Username Protected · **Posted:** 12 Apr 2023, 11:39

Username Protected wrote:

So what happens when it goes lower than 9 or 11 V? I was raised not to taxi before the flags pulled, etc, but I don’t understand how a G600 is powered on the battery bus vs any risk with the avionics bus on when starting?

My assumption was that it would shut off until the voltage came back - effectively it would reboot. This would be annoying as I would have to reset my V speeds, re-transfer my flight plan from Foreflight, etc but wouldn't be the end of the world. But I'm glad to know that my voltage doesn't sag enough to cause it.

Username Protected · **Posted:** 12 Apr 2023, 18:14

Username Protected wrote:

Especially an instrument designed for aircraft use will have "holdup" caps designed for transients well below the lowest rated voltage, so it can stay on during the start sequence. They don't always publish how long the holdup is for but typically a few hundred ms

That will deal with a quick glitch on start initiation, but it won't hold it up during a full start. That takes many seconds for a turbine.

A hold up of a few 100 ms would be long, and visually noticeable on shutdown. I suspect it is more in the 50 ms or less range. Having a long hold up requires using big capacitors. That in itself can be an issue for that means a high inrush at turn on, which wears out switches or relays.

Mike C.

Username Protected · **Posted:** 12 Apr 2023, 18:26

Username Protected wrote:

That in itself can be an issue for that means a high inrush at turn on, which wears out switches or relays.

Inrush can be limited to something reasonable

And my point was that during a start the time below the lowest operating voltage may be much less than the start sequence, so it can help

Username Protected · **Posted:** 14 Apr 2023, 00:07

Congratulations on the 500

I have a 501 SP with gross wt mod and no TR,s

Your mission is exactly what I do

No com flights to bahamas

11R MYEH is my main reason for purchase
Now anywhere in us is a go as well

These planes have increased in value in the past 5 years. Amazing

Be careful at high altitudes as summer gets here

As many 500/501 jets on here we should get a forum from administration 500/501
It’s Mike T,s fault!

I have never yet regretted my 501 SP purchase

Enjoy !