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Voltage Regulator giving up?

kevinmax

BENEFACTOR
Hello all,

I have a 1976 C-180J, with a Pponk, currently on straight Aerocets. About 10 days ago, on one of those REALLY hot days, climbing out of Seattle to cross the Cascades headed to Idaho, step climbing to manage the heat. Near the top of climb I have a couple things happen at about the same time (maybe THE same time): Low 'batt' warning on my JPI and a surging engine sound on a regular basis. Had pulse lights (LED), nav lights (incan) and beacon (tail mounters incan) all on. Turned off the nav lights to start shedding the load and more or less immediately the voltage came up a few tenths. Finished the flight like that, paying extra attention for burning smells, indications etc... All clear.

Next flight a few days later, and paying close attention, there's no surging in the headset, but I do see the voltage is running low if all lights are on, and I notice a flicker in the factory ammeter. The flicker runs about the same timing as the surging from the last flight. Also goes away when I turn off the beacon. Never noticed the recurring movement in the ammeter before.

This a.m. taxiing out, I notice, with all lights on, voltage is running a couple tenths HIGHER than normal. (Incidentally the flight was scrapped due to incoming wx)

Battery is a new Concorde last year.

Am I losing my regulator or is there a better place to start diagnosing?

Thanks for any thoughts!

Kevin
N7521K
 
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Possible regulator issue but also possible brush/slip ring issues in the alternator. What charging system is this? How much time on the alternator and regulator? But be aware that charging system issues should NOT be a cause of a surging engine.

Web
 
Thanks Web! I'll gather the equipment answers a.s.a.p. After the subsequent flight I'm sure the 'surging' was just in my headset as the beacon cycled. Not the engine.

Kevin
 
Thanks again Web.

Kelly Aero Regulator VR600, New 11/2014 about 220 hours ago
Rebuilt alternator P/N DOFF10300JR, 10/2013 about 317 hours ago

(wow, I need to fly more)

Kevin
 
Here's a pic of your charging system. First, the best way to check your alternator is to have it tested on a load bench. They'll spin it while loading it to max amps out to see if it holds the load. To check the wiring and reg, (engine off, master on) the A+ and S terminals need to be exactly at bus voltage. anything less and there is a connection issue. The F terminal will show something less than bus voltage, usually around 10 volts. The master switch, over voltage relay, or even the breakers can cause voltage drops which spoof the reg. Moving the wires or rocking the switch while the voltmeter is connected, can show intermittent connections. And check voltage at each end of the wires. Sometimes you may find a bad terminal or broken wire. If you think the test results show that you need a reg, a cheap way to check that is to install a reg from an old Ford car or truck. Same reg but at a fraction of the price.

Web
 

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It seems I have had a rash of alternator issues coming through the shop for the past 2-3 years with many of them as you describe. It has been a mixed bag of faults from regulators, worn brushes/slip rings, brush float from out of round slip collars, high winding resistance and bad diodes. Some have been very low time since overhaul and my personal feeling is that they have been alternators for too long. The majority have been remedied by installing new equipment even though there isn't a lot of economic solutions other than plane power. I'm not fully sold on them but they are new, I just don't agree with the Hartzell Engine Tech warranty process.
One thing I am pretty certain on is that there is no substitute for proper troubleshooting. Bite the bullet and go through the process and even get the alternator/regulator run on a bench. An automotive shop can do that for you sand see what the output capability really is. The Cessna AMM has a bench test breakout that is old school but accurate.
Ken
 
No argument here. I've been using Plane-Power stuff for years and I called Hartzell after the buyout to inquire about being a dealer for the Plane-Power line here in Alaska. The guy on the phone actually said that he didn't want anything to do with me and to just go get my stuff through one of the 'big' distributors. Now I have to bite my tongue every time I buy parts from them. But the line is good stuff in spite of s&^%$# customer service.

I've also seen lots of overhauled alternators fail soon after install and for a variety of reasons. My thought on this is that the over haulers are not doing the stress tests on the windings and rectifiers. Seems to easy to just do a visual and install new brushes.

Web
 
Web, thank you very much.

And Ken for your thoughts as well.

I'll be sure to go through the process properly to see where I end up. And go 'new' if it's determined a component needs replacing. Will report back.

Kevin




No argument here. I've been using Plane-Power stuff for years and I called Hartzell after the buyout to inquire about being a dealer for the Plane-Power line here in Alaska. The guy on the phone actually said that he didn't want anything to do with me and to just go get my stuff through one of the 'big' distributors. Now I have to bite my tongue every time I buy parts from them. But the line is good stuff in spite of s&^%$# customer service.

I've also seen lots of overhauled alternators fail soon after install and for a variety of reasons. My thought on this is that the over haulers are not doing the stress tests on the windings and rectifiers. Seems to easy to just do a visual and install new brushes.

Web
 
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