Questions about 2 batteries gauges and Anti-Coll light...

[Skulleader]

Hello guys,

 

In this moment I work with the electrical systems and I have one question about the Anti-coll light.

Before to start the APU my Anti-coll light work fine but when I start my APU the Anti-coll light is cutoff, is it normal ?

The Anti-coll light work fine again when my throttle are full open, is it normal ?

 

I have on second question but this time about the tow gauges of Batteries Load 1 & 2.

After my rampstart these gauges seems do not work, is it normal or one bug ?

 

I would like to thank you in advance because these two functions drive me crazy...

 

Bye, Skull.

[Strekaya]

When you start the APU, there is a fairly large drop in battery voltage, enough that depending on prior battery use or ambient temperature it may not be possible to stop and restart the APU for whatever reason on batteries alone. The batteries provide 24 volts DC at the start.

 

It appears that the collision lights stop working entirely at or below 20 volts DC, which is right around the threshold the batteries are providing after a battery APU start. (Often times, it's around 19 volts DC.) Once you start the main generators (or standby generator on the APU), or external power, this voltage jumps back up to 27 volts DC, and the collision light comes back on.

 

Leading to your second question, once you have either turned on external power, or the two main generators, or the standby generator, they are supplying power to the accumulator bus at or over 27 volts DC, and are no longer pulling from the batteries, and the battery load gauges drop to zero. In fact, the batteries are being charged during this time.

 

It is worth noting, though, that the APU load gauge (the lone gauge roughly above the anti collision light switch and to the left of the battery and rectifier switches) is meant to show load if the standby generator is on, but as of now still doesn't work.