Alternator issue?

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astaib
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Alternator issue?

Post by astaib »

Hello,

I was flying today when suddenly I had the following alerts:
"CAUTION" - Orange
"WARNING" - Red
'Alternator" - Red
"Low volt" - Orange

All these alarms where blinking and beeping not simultaneously like a Christmas tree :)!

I immediately checked the VM100, where I read:
29.2 volts (but the value was variating up to 30.xx)
21 amps (but the value was variating between 5 and 30 approx)

This continued every x minutes, then stops, then starts again... No matter, if I shut down the pitot heating and all possible instruments and lights?!

I finished the flight, called my mechanic and he told me that it is for sure an issue of charging and it might be the brushes. What do you think?

I had to come back to my home base (02h00 flight) after this flight and I again had this issues several times, but not continuously.

In the same time I had a lot of parasites that I can hear on the headset (these parasites starts not continuously some flights before the issue with the alarms this morning); my mechanic think that it is related, what do you think?

I tried during the flight today to shut down the alternator when I had these parasites, and almost 100% of the times the parasites stops.

Thank you for your help.


Arnaud.
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Arnaud
DA40 Star 180 / 40.026 / 2001
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Rich
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Re: Alternator issue?

Post by Rich »

With the excessive voltage, check the voltage regulator. VR's have been known to fail. Make sure its connector and wiring looks OK. The connector is a large black plastic cannon-type plug near the SlickStart.
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
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astaib
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Re: Alternator issue?

Post by astaib »

Can the excessive voltage damage something ?
Can it be the reason for « low voltage » and « alternator » alarm? Also can it be the reason for the parasites?

If the connectors and wiring are ok, what has to be replaced ?

Thanks again Rich!
Arnaud
DA40 Star 180 / 40.026 / 2001
Wingtip, landing and taxing LED (Whelen)
Skitube
GNS430 NON-WAAS
Steam gauges
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Rich
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Re: Alternator issue?

Post by Rich »

astaib wrote: Wed Mar 03, 2021 5:06 pm Can the excessive voltage damage something ?
Can it be the reason for « low voltage » and « alternator » alarm? Also can it be the reason for the parasites?

If the connectors and wiring are ok, what has to be replaced ?

Thanks again Rich!
The voltage regulator is a fairly small component that is mounted right behind the SlickStart. It's an Electrosystems VR2000-28-1 (D). Details in the AMM for removal/installation.
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
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astaib
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Re: Alternator issue?

Post by astaib »

Is it generic or diamond special component ?
Do you know if it’s an expensive one?

How can I be sure that it is the faulty component ?
Do you think that what I described can result of also an alternator issue ?

Sorry for all that question, but I have no knowledge on this !

Thanks
Arnaud
DA40 Star 180 / 40.026 / 2001
Wingtip, landing and taxing LED (Whelen)
Skitube
GNS430 NON-WAAS
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Rich
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Re: Alternator issue?

Post by Rich »

astaib wrote: Wed Mar 03, 2021 5:23 pm Is it generic or diamond special component ?
Do you know if it’s an expensive one?

How can I be sure that it is the faulty component ?
Do you think that what I described can result of also an alternator issue ?

Sorry for all that question, but I have no knowledge on this !

Thanks
It's 3rd party, but I think this model is specific to Diamond. I see it listed on Sky Geek for about $650.00. The product line (Electrodelta) is now owned by Lamar technologies. http://www.lamartech.com/voltage-regulators.html

If it were me, I'd replace the regulator as step 1. An alternator is a pretty dumb device. In alternators like this the voltage regulator controls the voltage supplied by adjusting the field current supplied to the alternator. This particular regulator is supposed to control voltage based on what it senses on pin 7 of the connector. Given a functioning VR, alternator malfunctions or almost always limited to failure to provide enough voltage or amps, not excessive voltage.

Having said that, flakiness in the connections to the VR could also produce this kind of behavior. Certainly I'd doublecheck that the connector is tight. This VR is electro-mechanical so internal chatter as well as a connection problems as it's operating erratically could certainly produce static in radios and such.

I have seen, during a jump start, voltage above 40 and nothing was damaged. But certain electronic components available aftermarket may fail if voltage gets beyond 32.
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
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Re: Alternator issue?

Post by astaib »

Thank you very much Rich, I will check the connections shortly first, then à a change of the VR is clever.

Last question: why low voltage alarm was blinking when it’s more « high voltage ». And also why amp meter was fluctuating ?
Alternator alarm was also blinking, why if it’s more a matter of VR ?

Arnaud.
Arnaud
DA40 Star 180 / 40.026 / 2001
Wingtip, landing and taxing LED (Whelen)
Skitube
GNS430 NON-WAAS
Steam gauges
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Rich
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Re: Alternator issue?

Post by Rich »

astaib wrote: Wed Mar 03, 2021 6:08 pm Thank you very much Rich, I will check the connections shortly first, then à a change of the VR is clever.

Last question: why low voltage alarm was blinking when it’s more « high voltage ». And also why amp meter was fluctuating ?
Alternator alarm was also blinking, why if it’s more a matter of VR ?

Arnaud.
Low Voltage and Alt. alarm both are signals from the VR, The VM1000 independently displays the voltage it is sensing. When you turn off the alternator side of the master you are actually turning off the VR.

The current sensor is independent and is reading the current flowing from the alternator. With the voltage being high the the amps could be expected to rise. There is a legitimate question where the extra amps are going, since . I expect into the battery. I don't know about you, but my normal current load in daytime has long been 8-9 amps. The only time it's above that is for a short duration (< 1 minute) after start of 22-25 amps to recover the battery charge. How old is your main aircraft battery?

One other note: The VR has an adjusting screw to set the nominal voltage. The DA40 MM says the VR will control voltage at 28 +/- 2.5 % (0.7 volts). My system voltage (measured at 2 points) runs 28.2 - 28.3. This is consistent with what others have reported.
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
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Re: Alternator issue?

Post by Steve »

Arnaud:

Rich has given you some useful information for troubleshooting the problem. I would carefully check all connections to the voltage regulator and alternator, as a loose, shorted, or broken wire can lead to over voltage. It is a lot cheaper to repair a bad connection than to buy a new VR, then repair the bad connection when the new VR doesn't solve the problem.

The VR2000-28-1 is not electromechanical, it is electronic. Here is a good article on how our VR works:
VoltageReg.pdf
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Good luck,

Steve
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Re: Alternator issue?

Post by astaib »

Hello,

I went today to my plane to check and tried to find something on this topic, the connector was a bit loose but was correctly locked, only the connector on VR side was able to twist.

I also removed the vr from the plane, opened it but nothing looked suspect (visually). I noticed that the manufacturing date is January 2017, so it is quite new but I cannot find any record of this VR replacement in the papers of the plane (I bought the plane in April 2018).

The alternator looks in good condition, a bit oily but shining. I’m not able to tell when it has been manufactured (is it something that is changed during engine overhaul?).

After remounting everything, I run the engine and I checked the red led on the VR, it never light ON.

I tried (on the ground) several configurations:
Everything ON (approx 20 amps)
Everything OFF (approx 2 amps)
1200 / 2000 / 2400 rpm
The tension was mainly steady at 28.4, but in some configuration it varies from 28.2 and 28.8 (idle rpm made a lower tension).
Then I tried to switch the ess bus on and the tension was 27.5.

Does it rings you a bell ?
Arnaud
DA40 Star 180 / 40.026 / 2001
Wingtip, landing and taxing LED (Whelen)
Skitube
GNS430 NON-WAAS
Steam gauges
Non certified ADS-b
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