Blackbird Sims / Milviz Forum Archive

As in the subject, with engine running at idle, rpm amperage draw still shows 0 with all electrical equipment turned on.

Hi,

With engine running, amperage displays generator load in amps.
When engine is in idle, there is no generator load hence needle remains at 0.

It is working properly.


Tomas

Hi Tomas,
Point taken for generator load gauge. Not it's more clear.

All electrical consumers draw approx 60Amps (if you turn on all equipment)
To reproduce, you need to start engine, run it at idle and enable all consumers. According to documentation, battery has capacity of 23Ah, so it should deplete completely in less than 30 minutes approximately.
Following your information, if engine is over 1000rpm, generator delivers 10Amps, so 50 still comes from battery. With 13000rpm, generator takes full load + additionally should have more load due additional amps required to charge battery.
With discharged battery, generator running at 1000rpm is still able to deliver full power to all consumers (60amps).
Additional issue is that strobe lights are still operational when battery is dead.

Jarek

jarek wrote: ↑

Mon Nov 05, 2018 6:10 pm

All electrical consumers draw approx 60Amps (if you turn on all equipment)

That is correct.

Following your information, if engine is over 1000rpm, generator delivers 10Amps, so 50 still comes from battery.

No. With all stuff on and generator charging, generator load is ~ 56 Ah:

With 13000rpm, generator takes full load + additionally should have more load due additional amps required to charge battery.

Correct. Generator load increases a bit (example after 1 minute of battery discharge):

With discharged battery, generator running at 1000rpm is still able to deliver full power to all consumers (60amps).

Correct.

Additional issue is that strobe lights are still operational when battery is dead.

Despite most electrical instruments are off, battery has some voltage (it is not 0); nav & strobe lights still work with very low batt voltage. Perhaps I put that limit too low, as all electric system is custom coded. I would have to revise.

Tomas

Well, to summarize generator operation with full electrical load (except boost pump) - this is what I see on this plane:

• from idle to 1000rpm load is 0

• between 1000 and 1300rpm, load is ~30Amps.

• above 1300 it peaks to 56 and then goes back after a while to 36. (looks like charge)

If you switch off generator with engine running, amperage goes back to -56. I believe some gremlin hides here...

jarek wrote: ↑

Mon Nov 05, 2018 11:24 pm

Well, to summarize generator operation with full electrical load (except boost pump) - this is what I see on this plane:

• from idle to 1000rpm load is 0

• between 1000 and 1300rpm, load is ~30Amps.

• above 1300 it peaks to 56 and then goes back after a while to 36. (looks like charge)

All of that is correct

If you switch off generator with engine running, amperage goes back to -56. I believe some gremlin hides here...

Correct, no gremlins. If you switch generator OFF the ammeter gauge reflects battery discharge, as you are now on battery power. Discharge value depends on how many systems are powered at the moment.

Tomas

What is your reading on the ammeter after battery has charged, say 3 minutes after you start the engine with all consumers turned on and engine running at 1300 rpm? I'm comparing power budget on battery (20V) and on generator (28V).