Generator charging issues

[Pilotkyle581945]

Hey everyone. Looking for some help with a problem I'm having with my PA-22. It's got me stumped. So I bought a digital voltmeter and plugged it into the cig lighter just to have an idea what was going on. Flew and the voltmeter was showing 16.5 volts. The previous owner had told me he kept blowing master fuses and I was thinking that could be why. Bought a replacement voltage regulator and the overvolting went away. However, now my plane only charges for maybe 3-4 minutes at around 13.5 to 14 volts and the amp meter shows around 18 amps or so. I have a 20 amp generator and I'm guessing it works as it's was constantly overcharging when flying before, but now the new regulator only charges it seems for a few minutes. Any ideas? What would cause the generator to just stop charging after 3 minutes. It's always the same pattern. Also the battery without load shows 12.7 volts but when I'm flying the volts start to decrease slowly. Thanks for any help.

[Steve Pierce]

What is the voltage in cruise? Normally an amp meter will show a charge after starting while it recharges the battery and then it sits in the middle. Sounds like your previous regulator was set to high and was over charging the battery and system. Here is info on th regulator and a previous thread on the subject. Look forward to hearing back.

https://www.shortwingpipers.org/foru...r-not-charging

[dgapilot]

As Steve said, amp meter will show high draw while the battery is recharging after start, then drop down to only the loads you are using (radio, lights). A simple test would be to see what happens after the charge rate drops off, turn on the landing and taxi lights (assuming they are still incandescent), the load on the amp meter should jump up.

If you keep your volt meter plugged in, before start it should read battery voltage (12v) after start it should read somewhere between 13.5v and 14.25v and stay there as long as the engine is running ( with a generator, voltage may drop with low RPM, below about 1800 rpm). At shutdown, it should drop back to battery voltage.

Hope this helps.


Sent from my iPhone using Tapatalk

[Pilotkyle581945]

What is the voltage in cruise? Normally an amp meter will show a charge after starting while it recharges the battery and then it sits in the middle. Sounds like your previous regulator was set to high and was over charging the battery and system. Here is info on th regulator and a previous thread on the subject. Look forward to hearing back.

https://www.shortwingpipers.org/foru...r-not-charging

Hey Steve,

So my buddy hooked up a volt meter to check everything out and with 0 load on the battery, it shows 12.7 volts. When I cranked it up and set it to 2000 RPM it showed about 18 amps+ for about 2 minutes. The voltage also showed around 14.1. However, after about 3 minutes, you see both the volts and amp meter start to drop off which I understand is normal. However, it never goes back up. By 5 minutes, the amps showed a negative draw and voltage was around 12.4 with nothing but the engine running. I turned on all my lights and the amp meter showed around -10 amps and the voltage dropped to around 11.5 volts. So I shut it down. After about an hour I tried again and got the same pattern. I've even tried switching the master switch while it's running and it does nothing. Thought maybe "recycling" would help but it didn't do a thing.

[dgapilot]

Did you try running over 2000 rpm? It could be that you need a higher rpm to get the generator on line (normally about 1800 should do it).

Have you tried recycling the master switch after the voltage drops? The master is a double pole switch, and one pole switches the field circuit to turn the generator on and off.

Check ALL your grounds! Engine to airframe, voltage regulator to airframe. Could be with low power draw there is enough resistance that the generator drops off line.


Sent from my iPhone using Tapatalk

[Pilotkyle581945]

Did you try running over 2000 rpm? It could be that you need a higher rpm to get the generator on line (normally about 1800 should do it).


Sent from my iPhone using Tapatalk

Yes I took it to 2300RPM. When I've been flying at 2450RPM the voltage shows around 12.2 volts and amps show negative.

[Steve Pierce]

Yes I took it to 2300RPM. When I've been flying at 2450RPM the voltage shows around 12.2 volts and amps show negative.

<br><br>And this is with a new voltage regulator? Troubleshooting instructions here.<br>https://www.shortwingpipers.org/forum/showthread.php?6050-Charging-Troubles

[Pilotkyle581945]

<br><br>And this is with a new voltage regulator? Troubleshooting instructions here.<br>https://www.shortwingpipers.org/forum/showthread.php?6050-Charging-Troubles

Yes with a new regulator. The fact the old one in flight was constantly overvolting tells me the generator works too.

[dgapilot]

Sounds like something is kicking the gen off line. Did you try resetting it (flipping the master on then off? Almost sounds like your new regulator isn’t working right. Is the new one a vibrator type or electronic? What part number regulator did you install?


Sent from my iPhone using Tapatalk

[MrBill]

Dga.....that last test killed him. Long live PilotKyle.