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Aural alerts for yellow range on EMS widgets? (Read 307 times)
May 26th, 2018 at 6:18am

gtae07   Offline
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Is there any possibility of getting aural alerts for selected EMS widgets that enter the yellow range?

I'm asking because I'm planning an electrically-dependent engine, and I want to configure some kind of aural warning that I've lost an alternator.  I'd planned to set the green range for voltage to a band around the usual alternator output, have it be yellow in the "operating on battery" range, and go red for a "critical battery low" condition.  But then I realized I wouldn't get a "caution" alert for the yellow range.

I also thought of an "alternator status" light widget but that would only give me "warning" and I am not sure if you can create multiple widgets off of one signal (e.g. a gauge and a discrete light).



 
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Reply #1 - May 26th, 2018 at 8:53pm

mmarien   Offline
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Murray M.
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Use an EMS pin to connect to the alternator inop lamp wire. It normally goes to ground when the alternator quits working. There doesn't have to be a gauge on the engine page to get the audio warning. If the alarm is set to SELF CLEAR or LATCHING for the contact, the red range will give an "Engine Monitor" audio warning. A scan of the gauges will show the voltage in the yellow range. An indication the alternate can't keep up or has quit altogether.

If you need a light, the notification area on Skyview will display a red WARNING. You also can connect a light to the EMS. It will come on anytime there is an EMS ERROR condition. Page 7-72 of the Install manual.

If all this happens and the voltage eventually drops into the "critical battery low" condition you probably don't need any more audio warnings to alert you about that condition. If you do have an "electrically-dependent engine" a second alternator is good insurance and failing that, knowing how far your battery will take you is a good survival plan.
 

Glasair II FT - o320 - P-Mags - EFII - MTV 3 Blade CS - VP-X - Single 10" Skyview - Stratux Dual Band - zooooom ...
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Reply #2 - May 27th, 2018 at 5:08am

gtae07   Offline
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mmarien wrote on May 26th, 2018 at 8:53pm:
Use an EMS pin to connect to the alternator inop lamp wire. It normally goes to ground when the alternator quits working. There doesn't have to be a gauge on the engine page to get the audio warning. If the alarm is set to SELF CLEAR or LATCHING for the contact, the red range will give an "Engine Monitor" audio warning. A scan of the gauges will show the voltage in the yellow range. An indication the alternate can't keep up or has quit altogether.

Hmm, didn't think about that approach.  I'd have to get the details but I wonder if the "low voltage" light on a B&C regulator would work...

Quote:
If you need a light, the notification area on Skyview will display a red WARNING. You also can connect a light to the EMS. It will come on anytime there is an EMS ERROR condition. Page 7-72 of the Install manual.

Yep, already planning on the master warning light. 

Quote:
If all this happens and the voltage eventually drops into the "critical battery low" condition you probably don't need any more audio warnings to alert you about that condition. If you do have an "electrically-dependent engine" a second alternator is good insurance and failing that, knowing how far your battery will take you is a good survival plan.

Planning on a dual-alternator, dual-battery setup.  I want the audio warning and not just a warning light because I want to know as soon as I lose an alternator--that way I can take the appropriate mitigation steps, and start the countdown for "estimated battery life remaining".  I've heard too many stories of "I didn't know my alternator had failed till stuff started dropping offline", and with lithium batteries getting that pretty much means you're out of juice.

The critical battery alarm would be more the "hey, you have 10 minutes left" warning, like the low fuel light in the car.  Again, with lithiums that critical voltage is over 12V; you won't get that progressive "stuff dropping offline" like you do on a lead-acid battery.  Everything will go till the battery cuts itself off at 11-ish volts.
 
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Reply #3 - May 27th, 2018 at 5:21pm

jakej   Offline
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Australia

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FWIW I set my ‘warn’ low volts at 13 (red) so that if an alternator fails in flight I’ll know immediately 😉 & have the alarm set to ‘latching’.
« Last Edit: May 27th, 2018 at 5:24pm by jakej »  
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Reply #4 - May 27th, 2018 at 6:01pm

mmarien   Offline
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Murray M.
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gtae07 wrote on May 27th, 2018 at 5:08am:
Planning on a dual-alternator, dual-battery setup.

With dual alternators can you think of a situation where you would need to run on battery power?

Alternators are an unlimited power supply. True, they do fail. However what are the chances of the second alternator failing before you run out of fuel. In other words, when the first alternator fails, the second will get you safely down at your destination. No battery power used at all. So really, all you need is a warning that the alternator has quit so that you can switch to the backup alternator.

gtae07 wrote on May 27th, 2018 at 5:08am:
I've heard too many stories of "I didn't know my alternator had failed till stuff started dropping offline"
Not going to happen if you use Jake's or my suggestion. You'll know exactly when your alternator quit. Wink

 

Glasair II FT - o320 - P-Mags - EFII - MTV 3 Blade CS - VP-X - Single 10" Skyview - Stratux Dual Band - zooooom ...
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Reply #5 - May 28th, 2018 at 8:58am

airguy   Offline
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I'm electrically dependent, with dual alternators and a single ETX-900VNT battery. I operate off the primary alternator as standard ops, but I always check the backup alternator for output during the runup. Occasionally in flight I will go to the backup alternator for 30 minutes or so just to verify it won't quit on me once it warms up.

I have the EMS warning set both on low voltage and high current discharge, so either way if the primary alternator goes south I will know it, and can switch to the backup.

As MMarien said, the backup alternator only has to last longer than the remaining fuel in the tanks - but the ETX-900VNT will give me another hour if for some reason the odds are stacked up against me so badly that I lose two alternators in the same flight. In that case, I'm buying a lotto ticket as soon as I land...  Cool
« Last Edit: May 28th, 2018 at 8:59am by airguy »  
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Reply #6 - Jun 2nd, 2018 at 4:36am

gtae07   Offline
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airguy wrote on May 28th, 2018 at 8:58am:
I have the EMS warning set both on low voltage and high current discharge, so either way if the primary alternator goes south I will know it, and can switch to the backup.


Setting based on current... there's an idea!  I like that. 

My thinking with dual batteries and alternators is somewhat along your reasoning--it's extra insurance.  It also gives me margin in case I lose the primary alternator and I'm in a situation where I need extra juice beyond what the aux alternator can supply.  The batteries give me a reserve I can draw upon until I can safely load-shed.
 
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