M

morsesc

Active Member
Hello everyone. I have the D180. During a cross country trip I received numerous "high voltage warnings". When I looked, the D180 was showing 14.7 volts. The warning would last only a few seconds and then the volts would drop down to 14.3 or so and then peak again after several minutes. The temperature was 99f when I left and I'm wondering if high temps can effect the voltage regulator's ablity to regulate the voltage? I flew today and was seeing 14.1 - 14.4 volts most of the time and never received a high voltage warning. I'm not sure what the "volts" mean. Is this what the battery is charged to or is it what the voltage regulator is out-putting to the battery?

Any ideas or thoughts?

Thanks, Rick.
 
Bus Voltage

That should be the voltage currently on the bus and at the voltage, feeding the battery from the alternator.
Have you got a blast tube on the back of the alternator? A hot regulator could cause the variation. Don't know what unit you have but a quick check of the wires around the alternator would be prudent.
 
Rick,
The voltage regulator causes high voltage. And High voltage can damage some electrical devices. The most likely cause is a bad connection between the voltage regulator and ground. The firewall shelf should not be painted under the regulator. There should not be any corrosion either and the mounting bolts should be tight. Another possible cause for high voltage is a bad connection someplace in the small yellow wire going to terminal "C". The bad connection could be at either end of the small yellow wire or the master switch could be going bad.
If not done already, Van's regulator cooling kit should be installed to prolong the life of the voltage regulator.
The way to test the regulator is to monitor the voltage between terminal C and the regulator case (fins) while the engine is running. If that voltage is normal, then the regulator is doing its job and is OK. If the voltage regulator is OK but system voltage is too high, then the problem is with the aircraft wiring as mentioned above.
Joe Gores
 
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First of all, thanks for the quick replies. I don't have the cooling kit for the regulator. I called Van's yesterday about this and the person I talked to didn't mention it. Will call again. I think heat is a factor because on my first flight yesterday, the voltage never got above 14.1 volts. After I landed and let the plane sit in the 90+ degree sun for an hour and then flew again, the voltage fluctuated between up to 14.3 - 14.4 during cruise. I will also ck the ground(s) connection and measure voltage between the small yellow wire terminal and regulator fins/ground. I have a Ducati regulator. What is a normal output voltage for these at cruise RPM? I think the yellow warnings start at 14.2 if I recall.

Rick.
 
Rick,

If you're operating in those kinds of temperatures if it was me I would install the regulator cooling kit as a matter of general principle. The kit was included as a part of the lighting kit because of the higher power demand, but even if you don't have the lights installed it just makes good sense to keep that unit as cool as possible. Heat is the enemy of electronics!

John
 
The most likely cause of your high voltage is a poor ground of the regulator case. Heat could also be a problem. Measuring the voltage between the small yellow wire and the regulator case is not a meaningful test unless the system voltage happens to be too high at the time.
I am going to guess at normal system voltage with the engine running to be somewhere between 13.6 and 14.2.
Joe Gores
 
External regulator

Mich48041 said:
The most likely cause of your high voltage is a poor ground of the regulator case. Heat could also be a problem. Measuring the voltage between the small yellow wire and the regulator case is not a meaningful test unless the system voltage happens to be too high at the time.
I am going to guess at normal system voltage with the engine running to be somewhere between 13.6 and 14.2.
Joe Gores
Click to expand...

If this is an external regulator I agree with Joe, check your ground reference on the regulator module. If it is an internal regulator check the cooling. Unlikely but also check the ground strap between the engine and frame.
 
I flew this morning with the OAT around 70 degrees f. The voltage varied between 12.7 to 14.2 (depending on rpm's). With the engine at cruise speed, the voltage stays around 14.1. This is within normal limits but is at the upper level of the green. I then checked the voltage between terminal C of the regulator and the regulator fins with a voltmeter. This voltage read the same voltage as was being displayed on the Dynon and never went over 14.1 volts. I also used the airframe as a grounding point with the same results. I am guessing now that the high voltage output was related to high heat at the regulator. Are the grounding points to check - the engine to the airframe, the battery to airframe and regulator to airframe? Also, does anyone know at what voltage the instruments can be damaged? I will be ordering the regulator cooling kit today.

Rick.
 
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I changed the voltage regulator and it's outputting 13.8 volts at cruise. I guess the original one was headed south.
 
John, I'm installing the regulator cooling kit this week. It has been reaching 105+ here lately. Also, I'm having to watch the oil temps during cruise. Nothing in the red but during climb I have to start pulling the throttle back and level off when oil temps hit about 225. Wish there was a way to blast some more fresh air on to the oil cooler...
 
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