Jump to content

Converting from generator to alternator


Recommended Posts

I'd start here:  http://www.plane-power.com/SAL12-70.htm  

 

If you're on a tighter budget, you might ask you mechanic if similar parts from a later Mooney can be retrofitted onto your O-360.  If so, I'd have the brackets, alternator, voltage regulator, etc. from an IO-360/M20J installation that could be used.  I don't know if the same alternator brackets can be used on the IO and O-360, but there is a good chance they will work.

Link to comment
Share on other sites

Consider getting a modern voltage controller for the generator. Low cost, big improvement. Identical foot print.

Rebuilt generators are available from aircraft Spruce. Easy to install, check with your A&P for details.

The biggest problem of the old technology was the mechanical controller.

Modern controllers fix that and provide benefits such as LED information about system status. Search this site for Zeftronics controllers.

Alternators do provide a wider voltage vs rpm output. So if you have to ground idle for extended periods of time, the alternator may be better.

Best regards,

-a-

  • Like 2
Link to comment
Share on other sites

I had to overhaul my Carb air box.  I had to remove the lower cowling, so I decided that I had all this removed and it was crazy not to do the Generator/Alt conversion. I also opted to replace the starter with the lightweight high torque starter as well. The hardest part of the whole install was trimming the baffling so the Alternator would fit. If you are good with your hands it is very easy. 

  • Like 1
Link to comment
Share on other sites

I just completed  a conversion to Plane Power 70 amp alterrnator in a 1965 M20E. Get the kit which includes the brackets, a solid state regulator, FAA337 form, and HIgh Voltage  warning lamp.  Here's the work required: Modify your front engine baffle to accomodate the larger unit, and seal around the opening with Red silicone rubber sheet (plain or fabric reinforced).  I placed a .025 aluminum reinforcing doubler around the larger opening on the bottom strap. You will have to remove the probeller and remove the front baffle to do the work. You will also have to buy a new V-belt  for the alternator because of different geometry.  You need to locate the HIgh Voltage lamp in your panel and wire it in with a 1 amp fuse or breaker. You also need to install a Field switch with 5 amp breaker, or combined Klixon breaker-switch so you can disconnect the alternator in case of overvoltage and protect your radios etc.  Your generator is probably 50 amp as is the main breaker.  The 337  is for an upgrade to  a 70 amp main breaker. However, in my case i left the 50 amp breaker in place since I don't have a big electircal load iln the plane.  

A lot of work, but much better 21st Century system.  Be sure to torque the the brackets tot he engine case exactly as requred by Lycoming, No more no less and safety same.  Also make sure you have a good ground strap between the engine and the airframe. DS 

Link to comment
Share on other sites

Getting the lower cowling off is the "hard" part. Alternator and light weight starter are the modern solution to the old problem. Doing it all at once makes the most sense.

Finishing it with a new Concorde battery would be the trifecta...(I've only read this here, but it's worth repeating)

Best regards,

-a-

Link to comment
Share on other sites

Go with the plane power. You will need to trim the front baffles to fit around the alt. Adjust the voltage regulator to 13.8 to 13.9V. You should be able to use the same belt as the generator. I used the same belt when I change on my former 64E.

  • Like 1
Link to comment
Share on other sites

Just to give another perspective...I replaced my generator (with a rebuilt unit) and my zeftronics(sp) control unit for minimal dough and spent my money installing a HID landing light. Zero issues. I also installed an EI volt/amp gauge so I know if I am discharging. No desire to "upgrade"

I am with Scott on this one:  Generators can be fine. 

Much of the trouble with old Mooney generator systems is due to the Delco regulator.   If you install a new Zeftronics regulator the generator will come on line at a reasonable RPM and keep the voltage buss within decent limits. 

For 'before' measurements see

http://mooneyspace.com/topic/247-electrical-gremlins/?hl=zeftronics

The Delco "regulator" does a perfectly horrible job of voltage regulation.  Not bad for 1930s technology, I suppose.

  • Like 1
Link to comment
Share on other sites

So, spend 300$ on a new controller to manage a generator which won't charge below 1400-1600 RPM (any ground ops), cracks the case, frequently needs the field flashed, has electrical "noise' which plays hell with your 25 grand radio stack, and weighs 11 lbs more than an alternator?  Am I missing something?

Link to comment
Share on other sites

The M20 type certificate includes newer alternators (such as Kelley) which can be installed without much paperwork since the M20 type certificate is good across all M20 models.  The costs may be cheaper to go this way without the need to purchase an STC from a different vendor whose product is  not on the type certificate.  Kelley had some issues in the past but I think these are now fixed.   Going this route would allow the installation of a 70 amp alternator and Zeftronics regulator with I believe lower cost and still get modern equipment.

 

John Breda

Link to comment
Share on other sites

Byron,

The only thing missing is the budget. Makes sense to go all modern, if affordable.

My 65 C did well with it's Zeftronics controlled generator.

The Narco radios it had would have benefited by smoke inducing voltage Spikes. But the spikes never came....

Best regards,

-a-

Link to comment
Share on other sites

So, spend 300$ on a new controller to manage a generator which won't charge below 1400-1600 RPM (any ground ops), cracks the case, frequently needs the field flashed, has electrical "noise' which plays hell with your 25 grand radio stack, and weighs 11 lbs more than an alternator?  Am I missing something?

yeah, You are...13lbs for How much does an alternator cost?  No issue with charging on ground with new regulator and my HID light gives awesome light at a minimal draw that doesn't challenge generator during taxi.  Once again, HOW MUCH IS the conversion?  I paid $700 for my ZeeVision HID with install and my control unit was NOT $300.

Link to comment
Share on other sites

I understand the arguments for and against, but my experience doing 35 mins of taxiing on the ground at a busy airport and departing into overcast did it for me. Not enough supply from the generator at those RPMs and about a minute into the soup I noticed the generator beaker had popped. Shut down less-essentials and reset. 10 mins to get it stabilized - all in IMC. Fortunately it was a very warm day. Else the need for pitot heat would have had me declare and return. Never again. Now I have the Plane Power conversion. Sent from my iPad

Link to comment
Share on other sites

yeah, You are...13lbs for How much does an alternator cost?  No issue with charging on ground with new regulator and my HID light gives awesome light at a minimal draw that doesn't challenge generator during taxi.  Once again, HOW MUCH IS the conversion?  I paid $700 for my ZeeVision HID with install and my control unit was NOT $300.

 

I just sold a brand new alternator for 250$, and I think the regulator is another 300$. Brackets for 100$, belt for 50$.   So ~800$ all in.   I totally agree on the XeVision HID, but the FAA's "AFS-300 Major repair and installation job aid", dated October 19th, 2012 pretty much bans future installations without an STC.  This really sucks because the Boom Beam is expensive. The LED's are an acceptable alternative, but they dont light up the runway at a mile and a half, though.

 

We already got ours installed in 2011, and its not coming out. We beat the letter. It stays.

 

"High-Intensity Discharge (HID) lamps and power supplies must have been issued STC for a particular make and model airplane
and Parts Manufacturer Approval (PMA) supplement lists’ specific eligibility for installation of HID as supplemental lighting only."
 
 

post-7887-0-69219900-1362877124_thumb.jp

  • Like 1
Link to comment
Share on other sites

Ned,

That is the deciding point. My airport is uncontrolled and departures are near immediate. So the point of start-up to generating electricity is not too draining. Waiting for a clearance on the ground, draining the single battery, and then departing into IMC lead me to change aircraft. Now, I have two batteries to go with that alternator....and a few other things.

Best regards,

-a-

  • Like 1
Link to comment
Share on other sites

JD-Thanks for putting up the link for the FAA info. 67 pages of more fun to read...

Anyone else have any issues with plane power's belt instructions. That gates belt mentioned in the STC is a 9335xl. I found it to be way too short on our gen to alt install. Ended up with a 1/2 in belt that is 38 and 3/8 long. It's on the long side and may run out of adjustment after it wares in. 38" looks to be the better length. Just wondering if I was the only one with this issue?

Thanks!

Link to comment
Share on other sites

  • 4 months later...

So, spend 300$ on a new controller to manage a generator which won't charge below 1400-1600 RPM (any ground ops), cracks the case, frequently needs the field flashed, has electrical "noise' which plays hell with your 25 grand radio stack, and weighs 11 lbs more than an alternator?  Am I missing something?

New controller G1500N is $158.75 from Aircraft Spruce.   Charging in my "C" begins at ~1200 rpm.   Never have manually flashed the field in past 6 years.    Noise on 12V buss is reduced greatly with G1500N compared to Delco - agree that it used to be terrible but most of that noise comes from the bang-bang Delco so-called regulator.  I measured it before and after, great improvement.  Weight, yes, generator is heavier.

  • Like 1
Link to comment
Share on other sites

FWIW, December 2012: 1966 E Log:

 

"Removed Jasco alternator, mounting brackets and voltage regulator, installed Plane Power, Ltd alternator and voltage regulator in accordance with STC SA10682SC and master drawing list no. 14-5001 rev B dated 11-19-09. Weight and balance updated. Equipment list updated. AFMS placed in aircraft POH. Instructions for continued airworthiness placed in aircraft permanent records. Form 337 completed this date."

 

(The new Plane Power is 70A but the CB and wire size in place with the old 50A Jasco were adequate.)

 

$1400. parts and labor

Link to comment
Share on other sites

I replaced my generator with a plane power alt before they completed the conversion kit. I installed a zephtronics regulator and had to get a field approval for the installation. I was set to convert to a standard mooney system but my engine was built before they had the boss mount and the original alternators did not have a case mount...at least not one that would work. If you do try to do a direct conversion it is considered a minor mod and only a log book entry is required, but you will have to change the started ring/pulley assembly along with the belt because the alternator uses a thinner style belt. My recommendation would be to just install the plane power convention kit.

Brian

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.