We had an unusual problem in our DA40 that none of our mechanics/IAs have seen before.
After engine start smoke started coming from cowling.
The mechanics determined that the ground somehow got energized and heated up the metal fasteners on cowl melting the fiberglass,
They don’t know what to replace or how to troubleshoot,
If we put master on, everything powers up normally.
We did just change out the alternator.
Anyone seen this problem before?
Ground getting energized
Moderators: Rick, Lance Murray
- startingovercfi
- 2 Diamonds Member
- Posts: 33
- Joined: Thu Sep 25, 2014 12:32 am
- First Name: Jeff
- Aircraft Type: DA40
- Airports: 39N
- Has thanked: 2 times
- Been thanked: 13 times
- astaib
- 5 Diamonds Member
- Posts: 617
- Joined: Mon Feb 26, 2018 9:00 pm
- First Name: Arnaud
- Aircraft Type: DA40
- Aircraft Registration: FGNJX
- Airports: LFPX
- Has thanked: 244 times
- Been thanked: 51 times
Re: Ground getting energized
How is connected the new alternator ?
F1
F2
Ground
Aux
??
Is it a lyco version ?
F1
F2
Ground
Aux
??
Is it a lyco version ?
Arnaud
DA40 Star 180 / 40.026 / 2001
Wingtip, landing and taxing LED (Whelen)
Skitube
GNS430 NON-WAAS
Steam gauges
Non certified ADS-b
DA40 Star 180 / 40.026 / 2001
Wingtip, landing and taxing LED (Whelen)
Skitube
GNS430 NON-WAAS
Steam gauges
Non certified ADS-b
- Charles K
- 4 Diamonds Member
- Posts: 308
- Joined: Mon Feb 21, 2011 7:46 pm
- First Name: Charles
- Aircraft Type: DA40
- Aircraft Registration: N5WU
- Airports: KCCR
- Has thanked: 26 times
- Been thanked: 98 times
Re: Ground getting energized
Did you put in a plane power 150A alternator. That alternator's positive terminal will short out against the air vent metal pipe for the alternator. The plane power alternator does not need that. Another member here tipped us off to that. I let shop know when they put it in and they had that part cut shorter and welded shut (the PP alternator does not need the outside cooling air - it has two built in fans.
Charles
KCCR Based
N5WU - 2004 G1000 DA40 40.400, GTX345R ADS-B, WAAS Upgraded in 2021 via Diamond Upgrade Program
IFR and ME Rated - Advanced Ground Instructor Rated
KCCR Based
N5WU - 2004 G1000 DA40 40.400, GTX345R ADS-B, WAAS Upgraded in 2021 via Diamond Upgrade Program
IFR and ME Rated - Advanced Ground Instructor Rated
- startingovercfi
- 2 Diamonds Member
- Posts: 33
- Joined: Thu Sep 25, 2014 12:32 am
- First Name: Jeff
- Aircraft Type: DA40
- Airports: 39N
- Has thanked: 2 times
- Been thanked: 13 times
Re: Ground getting energized
That is the one we installed. Good lead. I will have them take a look at that. Thanks.Charles K wrote: ↑Fri Apr 09, 2021 10:26 pm Did you put in a plane power 150A alternator. That alternator's positive terminal will short out against the air vent metal pipe for the alternator. The plane power alternator does not need that. Another member here tipped us off to that. I let shop know when they put it in and they had that part cut shorter and welded shut (the PP alternator does not need the outside cooling air - it has two built in fans.
- Steve
- 5 Diamonds Member
- Posts: 1972
- Joined: Thu Aug 12, 2010 1:23 am
- First Name: Steve
- Aircraft Type: DA40
- Aircraft Registration: N432SC
- Airports: 1T7
- Has thanked: 85 times
- Been thanked: 503 times
Re: Ground getting energized
Wow, that is amazing, but it makes sense. Our composite cowling could act as a resistive load between an inadvertent B+ contact point and ground through one of the Dzus fittings. Unlike a metal cowling it wouldn't cause a dead short.
An important reminder to check clearances when working under the cowl...
An important reminder to check clearances when working under the cowl...
- startingovercfi
- 2 Diamonds Member
- Posts: 33
- Joined: Thu Sep 25, 2014 12:32 am
- First Name: Jeff
- Aircraft Type: DA40
- Airports: 39N
- Has thanked: 2 times
- Been thanked: 13 times
Re: Ground getting energized
The essential bus breaker was popped. Does that help any? Still troubleshooting