Generator replacement

[mooney27239]

My generator failed today on my '65E and I am faced with either rebuilding it or going with a alternator conversion. I would be interested in hearing from others who have been in this position and their decision. If you went with the conversion what did it cost, any unexpected bugs, etc. At this point I am not sure which way to go.

[scottfromiowa]

Check through the archive posts.  There is recent discussion regarding Generator or Alternator...

I am in the Generator camp as will be shown in previous posts.  Good luck!

[takair]

Yes, see Voltage Regulator II postings. 

[MooneyMitch]

Quote: mooney27239

My generator failed today on my '65E and I am faced with either rebuilding it or going with a alternator conversion. I would be interested in hearing from others who have been in this position and their decision. If you went with the conversion what did it cost, any unexpected bugs, etc. At this point I am not sure which way to go.

[kerry]

I had a local guy overhaul my generator for under $100.  At the same time I replaced my volt regulator with a zeftronics.  I've been very happy since.

[1964-M20E]

Installing the Plane Power alt conversion in my 64E model tomorrow.  Will let you know how it goes.

My gen quit two weeks ago I changed the burshes only to realize I had two windings that were open two saturdays and a sunday spent on this.

 

 

 

[MooneyMitch]

Ok, this sounds great!  More power to spare with the conversion.  Keep us posted please.

[Alan Fox]

It truly amazes me how cheap people can be , for 1000 1200 dollars you can have an alternator that will out perform your old one , weighs ten lbs less , have a solid state regulator , and have fifty years of technology and manufacturing enhancements over the crappy generator that is in there now ..  I think if the difference in price is that important , you truly CAN NOT AFFORD to fly , If you take passengers or fly at night , or especially if you fly IFR , the difference can be life or death....   

[scottfromiowa]

It really amazes me that people can say they are amazed by other people assuming they are "cheap" when they really have weighed the benefits of an alternator (lighter, more powerful) vs the cons (radio noise, expense, value/need for MORE power?)  My scale leaned to generator.  After I replaced the generator/belt and voltage regulator (all were over 40 years old) the systems have worked perfectly.  I have a HID landing light as well as wing tip strobes and installation for what the alternator upgrade would have cost.  This "cheap person" feels safer at night with HID and strobes as well as all new system vs. an alternator.  But hey, that's just me.

[1964-M20E]

The good news is the old generator belt works fine with the new alt.  I thouhgt I might have to pull the prop.  The plane power generator is in and hooked up.  I did a test run today and it worke fine.  I still need to put on the colwing but I'm wating on the flexiable rubber boot between the airfilter box and the throttle body.  Also my Money is getting a nose job, new paint, since I had the cowling off.  I'll post some pics.

[carusoam]

Scottfromiowa,

We were labeled as "cheap", and it indicates that as generator owners we choose "death".

I don't feel that either an alternator or generator failure is going to require immediate death, and I think we all agree that owning a Mooney isn't cheap.

Now I own a plane with an alternator, I don't feel any less cheap or any more safe.....

Other than that, I hear jet engines are really reliable.....

Best regards,

-a-

[67M20F]

I have had 3 gen fail on me, maybe I should write a post on one that would change some minds. But alas I still have a gen, thanks to a partnership that has now been expired.....

[rob]

Quote: n74795

It truly amazes me how cheap people can be , for 1000 1200 dollars you can have an alternator that will out perform your old one , weighs ten lbs less , have a solid state regulator , and have fifty years of technology and manufacturing enhancements over the crappy generator that is in there now ..  I think if the difference in price is that important , you truly CAN NOT AFFORD to fly , If you take passengers or fly at night , or especially if you fly IFR , the difference can be life or death....   

[67M20F]

I don't think that overhauling a gen is being cheap, just not the best decsion you can make, I think that an alt is better, more reliable.

[rob]

I don't think there's a marked difference in reliability between the alternator and generator options on our aircraft. As this thread clearly points out, there is quite a bit of personal preference involved in the decision. Replacing a generator with another generator may not be the decision you would make, but it's obviously one that several of us have made. I can't speak for others, but in my case the delta in price is negligable and was not a factor in my decision.

[flight2000]

Am I correct in thinking that an alternator provides charging at lower RPM's versus the generator which needs to have higher RPM's to begin effective charging?  Might be worth the conversion if your based at a busy airport where delays or looooong taxi's can drain a battery quickly.  Just a thought. 

Mine already had the alternator in it when I bought it, so the decision was made for me.  I did have to replace it in April after it crapped out, but it lasted 13 years since the conversion in '97.  Not bad.  It cost me a little in blood since I assisted in the change out.  The lower cowl is a B*&% to get off.....

Brian

[DaV8or]

Quote: flight2000

The lower cowl is a B*&% to get off...

[DaV8or]

Things to consider on this subject:

Generators don't work at low RPM.

Generators weigh about 6-7 lbs more.

Generators run hotter and need more cooling.

There are no airplanes, cars, trucks or boats sold in America that have a generator in it and it's been that way for about 40 years.

You can buy a brand new, zero time, factory built alternator. Generators are just rebuilt.

Genarators make less power per size and weight.

In generators defense:

Generators are easily rebuilt.

Generators die slowly, so you often get a bit of warning before lights out.

A generator may already be in your plane and so the cheapest way to keep it flying.

 

[mooney27239]

For everyone's info, my AP called yesterday and said he had called about rebuilding my generator. They told him they had one set of brushes left and no more brushes were being made so my generator would be the last that they rebuild. Not sure if this is just true for this particular rebuilder or for everyone. Not sure who he called either. If true for everyone, this debate will become a non-issue, we will all be running alternators eventually.

[scottfromiowa]

This thread is...like a generator...it keeps going and going...and going.

[Gone]

One more data point, and I am going to start off by saying that I have heretofore been squarely in the "if the generator works - don't mess with it" camp.  I am like Scott.  By replacing my old Delco GCU with the Zephtronics one, and changing out the landing light to a brighter one with less than 8 amps of draw, I was good to go.  Generator also has the advantage of not needing a reference voltage to work.

Then yesterday happened.

Taxiing on the ground in Montreal for over 40 minutes at relatively low rpms.  JPI was reading as low as 11.2 at one point.  No problem.  Been there before.  Holding short, I turned it all on:  pitot heat, overhead lights, panel lights, fuel pump, landing light, strobes.  Rolled on 28 for the left turn to climb into the soup.

Enter IMC and already on the scan.  JPI starts flashing "Bat" and I looked at the generator circuit breaker.  It was tripped, so I pushed it in.  One minute later, it pops again and the JPI is showing a battery voltage of about 10.6 volts. Now I have some decisions to make. 

What are the options?

1.  Abort now

2.  Do some electrical IA (immediate action) to identify the problem and maybe avoid uneccessary action.

I chose option 2 and always had the option of reverting to option 1.  Looked at OAT (14 degrees celcius) so turned off pitot heat.  In the soup, so turned off the landing light.  Above 1000' so turned off the fuel pump.  Then pushed the breaker back in. 

It stayed.  20 minutes later, the battery was reading 12.8 so I brought the pitot heat back, and 20 minutes later the landing light.  By this time the battery voltage is reading 13.7.  Good to go.

What was the problem?  IMO, the battery was so far down that it was drawing more from the generator than the circuit breaker rating - hence its popping.

Result of this investigation?   I am going to get the Plane power alternator conversion so that low rpm taxi manoeuvering at larger airports does not stress the system as much. 

Sorry Scott.  Not today, and maybe not until next annual. But I am converting to the alternator.  Two instances of the generator breaker popping while in bumpy soup is two too many for me.

[carusoam]

Ned,

In the meantime you may consider changing out the circuit breaker for a new one.  Apparently, as they age, they fail at lower loads than their rated for?

It would be great to know the actual load of each item as they are turned on.

-a-

[DaV8or]

Quote: carusoam

Ned,

In the meantime you may consider changing out the circuit breaker for a new one.  Apparently, as they age, they fail at lower loads than their rated for?

It would be great to know the actual load of each item as they are turned on.

-a-

[Kwixdraw]

Keep in mind that the breaker is supposed to pop at 80% of it's rated capacity.

[danb35]

Quote: Kwixdraw

Keep in mind that the breaker is supposed to pop at 80% of it's rated capacity.