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  #1  
Old 03-19-2019, 04:36 PM
Tacco Tacco is offline
 
Join Date: Jan 2017
Location: White Salmon, WA
Posts: 107
Default VR Infant Mortality ?

I have a total of 6 (six) hours on my 12 ULS. This morning the system was not charging upon start up or during run-up.

Could the VR have failed this early? I suspect a connection has vibrated loose but I reseated the connection at the VR with no effect. Where else should I check?
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  #2  
Old 03-19-2019, 05:17 PM
Slider52 Slider52 is offline
 
Join Date: Aug 2013
Location: Everett, Wa.
Posts: 1
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I had a defective master switch that gave me the same symptoms. It might be worth checking.
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  #3  
Old 03-19-2019, 05:38 PM
Mich48041 Mich48041 is offline
 
Join Date: Apr 2008
Location: Riley TWP MI
Posts: 2,886
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Check the voltage on regulator terminal "C". It should equal battery voltage.
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  #4  
Old 03-19-2019, 05:47 PM
Tacco Tacco is offline
 
Join Date: Jan 2017
Location: White Salmon, WA
Posts: 107
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Voltage at C looks good.

How did you diagnose the master switch issue?
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  #5  
Old 03-19-2019, 06:57 PM
Mich48041 Mich48041 is offline
 
Join Date: Apr 2008
Location: Riley TWP MI
Posts: 2,886
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If the voltage on terminal C is OK, then the problem is most likely within the voltage regulator.
The master switch is not the problem.
Read THIS thread:
http://www.vansairforce.com/communit...ad.php?t=80487
AM101406, or MIA881279, or JDR1406 are alternative regulators,
although the mounting and electrical terminals are different.
eBay item number:163565296051
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  #6  
Old 03-20-2019, 10:16 AM
Tacco Tacco is offline
 
Join Date: Jan 2017
Location: White Salmon, WA
Posts: 107
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So far, i’ve...

1) Checked the Stator coils. Measured about half an ohm resistance between the two heavy yellow wires at the regulator.

2). With the Master ON ( Mag A & B OFF), measured battery voltage from ground to the thin Yellow wire (“C” terminal).

3) Checked battery wire continuity. With the Master still ON, measured from ground to each white wire (“B” and “R” terminals). Measured battery voltage at both.

4) Checked the regulator ground but I did not do so at load. Looks pretty good though with lots of contact area.

So....it’s indeed looking like a bad regulator. I just can’t believe it failed a six hours. I have a new one inbound and will install it to confirm. Also have ordered the S H kit from Van’s.

Now I’ll have to decide wether to keep the Ducati installed to finish the test program or just bit the bullet and install the H S kit now. (I’ll be crying as I cut into my flawlessly painted cowl.)

Btw, since I was in test and downloading data, I looked back and found the the charging amps went negative for a short time during the last flight and then failed hard during approach. I didn’t notice it until startup the next day.

Thanks everyone for your help.

Last edited by Tacco : 03-20-2019 at 10:17 AM. Reason: Grammar
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  #7  
Old 03-20-2019, 10:30 AM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 1,494
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I assume you have VR mounted on firewall shelf under cowling. A third option not requiring cutting of the painted cowling... install John Deere VR in same location as Ducati. Search this forum for installation and wiring. This is path I followed when my Ducati VR failed at ~100TT. Now have 400TT and JD VR is going strong mounted in same location on firewall shelf.

I have adapted a procedure to open oil access door when done flying in order to vent residual heat. Maybe this helps?

Looks like you won the prize for least hours for failed Ducati VR...
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1130 hrs Flying 46 Piper J-3 Cub N6841H
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  #8  
Old 03-20-2019, 11:57 AM
DHeal DHeal is offline
 
Join Date: Sep 2006
Location: Windsor, California
Posts: 824
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Another data point: My first "firewall-shelf mounted with blast tube" Ducati RR failed at @ one-year-old and 133 Hobbs hours -- IMHO the failure was caused by heat, vibration, and poor internal soldering. I installed the replacement Ducati RR under the avionics shelf per Van's suggestion and added a small forced air duct to blow a bit of ambient air across the RR's cooling fins. This set-up has been running fine for the past 600+ Hobbs hours (Knock on wood!!). I honestly don't know how I will proceed when my current RR fails -- either just replace it with another Ducati or perhaps try the SH or other brand RRs in use. I will be curious to see if the stepped recharging cycle of the SH works adequately with short duration flight operations (i.e., less than one hour).
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  #9  
Old 03-20-2019, 12:51 PM
Tacco Tacco is offline
 
Join Date: Jan 2017
Location: White Salmon, WA
Posts: 107
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My VR is mounted in the cockpit. I agree that temperature eventually does these things in. However I think mine is clearly a QA issue, probably helped along by poor design. The first flight was January 1st and all of the six hours of operating time were conducted in 30-40 degrees outside temps. Probably 50 in the cockpit.
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  #10  
Old 03-21-2019, 07:42 AM
John-G John-G is offline
 
Join Date: Jan 2012
Location: Northeast Ohio
Posts: 589
Default regulator alternative mounting location

I decided to opt for an alternative mounting location for my Silent Hektik voltage regulator. My RV-12 has the old style cowling with the ducting going to the coolant regulator mounted on the firewall.

Taking a page from Jean-Pierre's (WingedFrog) playbook where he mounted his voltage regulator inside the air duct in the lower cowling in front of the coolant radiator .... and blending that idea with John Bender's (JBPILOT) "Bender baffle", I mounted my regulator inside the air duct and on the baffle plate.

The install now has 50 hours on it and I'm guessing Jean-Pierre and I probably have the coolest running regulators in the RV-12 fleet.

Below are a couple of photos of the SH regulator mounted on the "Bender baffle". To accommodate the mass of the regulator, I used bushings and large washers above and below the baffle to insure a tight fit on all axis and installed hard stops to establish full closed and full open limits. Wiring goes to a screw down terminal strip mounted on the firewall shelf. The old Ducati regulator was left on the firewall shelf as a backup (which I will likely never need).

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Last edited by John-G : 03-21-2019 at 07:49 AM.
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