JABIRU ELECTRICAL

[MAB123]

Hi All

 

This subject may have been addressed before i am new to the Jabiru fold any help would be good

 

I own a J230/430 with 3300 eng

 

I am having trouble with the aultinatior putting out enough power to run the EFIS ,GPS and Radio

 

it doesn't start charging until 2000rpm [plus] than struggles.

 

One suggestion is fit an SD20 ault which bolts on on the vacuum mount has this worked or can the existing Ault be rewound for more Amps

 

Thanks Martin

 

 

[old man emu]

First step is to eliminate the simple things.

 

1. Is the pulley belt tight? If the blet slips, the alternator won't spin fast enough. Rule of thumb is to tighten the belt so that it can be pushed in about 1/2" at the halfway point beteen pulleys.

 

2. Is the pulley belt in good condition? If it has been overtightened, the inner surface of the belt might have become polished and couls slip on the pulleys.

 

3. Are all electrical junctions bright and shiny? Dirt and corrosion are the best things to stop an electrical system from working.

 

4. Are all electrical connections tight? No join - no juice.

 

Despite what all the howls from the naysayers, Jabiru does produce a product that works. Don't go blaming the product if it has been poorly maintained.

 

Old Man Emu

 

 

[jetjr]

Jabs altenator is incorperated into the back of the engine flywheel so no belts.

 

Something seems wrong as it should easily power what your indicating.

 

The lack of charge under 1700rpm seems normal, the regulation setup has been known to give trouble

 

OME is right regarding clean terminals and fittings.

 

 

[MAB123]

Jabs altenator is incorperated into the back of the engine flywheel so no belts.Something seems wrong as it should easily power what your indicating.

The lack of charge under 1700rpm seems normal, the regulation setup has been known to give trouble

 

OME is right regarding clean terminals and fittings.

HI Thanks I had alame look at it than I replaced the regulator which they said was faulty still having charging problems do you know if anybody has fitted an SD20 Ault to the vacuum mount

 

 

[old man emu]

I told you that Jabiru makes a good product. See how they saved weight by eliminating pulleys and belts?

 

The regulators (not being a Jabiru product) have given trouble. Do the otehr wiring checks before you do anything else.

 

I wonder if all the whizz-bang electricky stuff that you have in your airplane is just a bit too much for the alternator. But then again, We've got two full glass panel Jabs that are going OK.

 

OME

 

 

[geoffreywh]

The problem is:- The crank doesn't turn fast enough to make any decent amount of power. The motorcycle that the alternator came from has a cruising rpm of around 7-9 thousand rpm NOT 28-29 hundred, as on the 230. (That is just about idle on original fitment) So the cure was for Jabiru to fit a belt and pulleys to get the thing to turn fast enough!....

 

 

[MAB123]

So what is the answer to the problem

 

 

[Kenchhidu]

The problem is:- The crank doesn't turn fast enough to make any decent amount of power. The motorcycle that the alternator came from has a cruising rpm of around 7-9 thousand rpm NOT 28-29 hundred, as on the 230. (That is just about idle on original fitment) So the cure was for Jabiru to fit a belt and pulleys to get the thing to turn fast enough!....

The rotax alternator is on after the reduction drive!!! Don't start that jab knocking again.

 

 

[jakej]

HI Thanks I had alame look at it than I replaced the regulator which they said was faulty still having charging problems do you know if anybody has fitted an SD20 Ault to the vacuum mount

I have - on a Jabby I wired for IFR . I'd be glad to give you a few pointers, just pm me.

 

Jake J

 

 

[jakej]

First step is to eliminate the simple things.1. Is the pulley belt tight? If the blet slips, the alternator won't spin fast enough. Rule of thumb is to tighten the belt so that it can be pushed in about 1/2" at the halfway point beteen pulleys.

 

2. Is the pulley belt in good condition? If it has been overtightened, the inner surface of the belt might have become polished and couls slip on the pulleys.

 

Old Man Emu

 

 

[Vev]

Hi Martin,

 

Your alternator is an 18amp job and should be showing a positive charge well before 2000 rpm. Apart from checking all of the connections, including the earths etc etc.

 

The voltage reg/rectifier is a little underdone and can be replaced with a better unit ....

 

However it sounds more like your alternator is on its way out or already gone west. Take a look at the stator windings through the back of the stator holder inside the rotor and see if the windings look black or at least very dark brown. If they are black its a good bet you have lost a pole winding or two.

 

Unlike almost all motorcycle stators, the stator body is insulated which doesn't allow one to do the normal short circuit tests (finding continuity to the stator body from the output wires), which means you need to take a look at it and see if its had a melt down. I have seen one or two windings on the poles fused together after burning out and still showing some charge albeit marginal.

 

Hope this helps.

 

Cheers

 

Vev

 

 

[fly_tornado]

There was a jab at clifton with electrical issues, turned out that the stator had shaken itself to pieces. When they pulled it too pieces you could see all the wiring was loose.

 

 

[MAB123]

Hi Martin,Your alternator is an 18amp job and should be showing a positive charge well before 2000 rpm. Apart from checking all of the connections, including the earths etc etc.

 

The voltage reg/rectifier is a little underdone and can be replaced with a better unit ....

 

However it sounds more like your alternator is on its way out or already gone west. Take a look at the stator windings through the back of the stator holder inside the rotor and see if the windings look black or at least very dark brown. If they are black its a good bet you have lost a pole winding or two.

 

Unlike almost all motorcycle stators, the stator body is insulated which doesn't allow one to do the normal short circuit tests (finding continuity to the stator body from the output wires), which means you need to take a look at it and see if its had a melt down. I have seen one or two windings on the poles fused together after burning out and still showing some charge albeit marginal.

 

Hope this helps.

 

Cheers

 

Vev

Hi

Thanks for that

 

The eng /A/frame has only done 40hrs since 2007 Ipurchased it with 35hrs in may this year 2011 and have had some small problems mainly because it has not been used I was expacting to spend some money on it due to the lack of use.

 

All looks good with the ault visual check what reg do you suggest as a replacement

 

Thanks Martin

 

 

[Guest DonC]

HiThanks for that

The eng /A/frame has only done 40hrs since 2007 Ipurchased it with 35hrs in may this year 2011 and have had some small problems mainly because it has not been used I was expacting to spend some money on it due to the lack of use.

 

All looks good with the ault visual check what reg do you suggest as a replacement

 

Thanks Martin

[Guest DonC]

Disconnect the alternator and check the AC output as you increase revs - should go up to 20+ volts

 

 

[deadstick]

The maint manual has some checks to perform with an ohm meter, also there is a pull test to see if the magnets are cactus. I would be looking at magnet strength and earth, the fact it's not charging at low rpm woul have me looking at the reg first then earths then windings and magnetic strength. Good luck and don't forget to post results as you go!

 

Where is it located?

 

 

[old man emu]

Don't go wasting time looking for non-existent problems. If owners want to specify glass cockpits and run GPS, radios and then feel the need to turn on every light fitted to the plane, then you can't expect an alternator that was designed for airplanes with analogue instuments and to maintain power supply during cruise to live up to the task.

 

Just consider these questions:

 

1. Is it essential to use the GPS to taxi to the runway threshold?

 

2. Is is absolutely necessary to have every light illuminated during the day?

 

3. Is it necessary to have the transponder turned on in the circuit?

 

The Jabiru alternator will handle the load if unnecessary electronics are turned off until the aircraft engine is running at climb or cruise revolutions. Once that has been reached, turn on the electronics as required.

 

OME

 

 

[deadstick]

OME, should be charging at low rpm, I maintain full glass versions and they all have no problem, mine charges fine at idle so I think he has a problem. Ie weak field strength etc

 

 

[mlpinaus]

Gidday. I have a complete glass cockpit. Look at my avatar. Avmap, Efis, ems , Radio1, Transponder, Radio2 and Autopilot. The avionics switch is turned on after engine start, and is left on. It just works. I do keep a battery smart charger on in the hangar to maintain full charge, but that is it. Check the alternator.

 

regards

 

Marcus

 

 

[nong]

You might have have an eight pole stator. These are fine, but later engines use a ten poler.

 

If your cockpit is stinky/toxic it might be the glue (epoxy?) melting as the windings destroy themselves.

 

Jab can supply rewound stators at a reasonable price.

 

 

[geoffreywh]

your stator may look like this?.......................note especially where the rotor has rubbed on the screw heads!