Alt Field Circuit Breaker Popping


Corbin
 

I am chasing down an alternator related issue and running out of ideas.  During a flight, the Alt Warning bulb started flashing and I noticed a discharge on the Amp gauge.  The Volt gauge was showing 11 volts.  I returned to land and troubleshoot.  I pulled the engine to get the alternator off and I found the rod/spindle had sheared close to the gear.  I got a different alternator and swapped the rod and gear.  I did a bench test by connecting a multimeter to the batter terminal on the alternator and used a drill to spin the alternator.  It read a volt output of 14-18volts.  I assume all is find with the alternator.

I re-installed the alternator and put the engine back on.  However, the circuit breaker (5amp) trips as soon as the Alt is turned on.  

Is it likely the voltage regulator that has gone bad?  Any ideas?

Thanks,

Corbin Ge!ser


Jay Scheevel
 

Not sure what regulator you currently have, but you can probably Google up the installation manual if you know the make and model. This will tell you how to test it with a voltmeter between different contacts looking for expected values within tolerances. I would also make sure your battery is fully charged before trying start and test amternator again, in order to minimize load on the charging circuit when you flip the field switch on after starting. Good luck trouble shooting.

Cheers,
Jay

Sent from my Verizon Wireless 4G LTE DROID


"Corbin Geiser c_geiser@... [Q-LIST]" <Q-LIST@...> wrote:

 

I am chasing down an alternator related issue and running out of ideas.  During a flight, the Alt Warning bulb started flashing and I noticed a discharge on the Amp gauge.  The Volt gauge was showing 11 volts.  I returned to land and troubleshoot.  I pulled the engine to get the alternator off and I found the rod/spindle had sheared close to the gear.  I got a different alternator and swapped the rod and gear.  I did a bench test by connecting a multimeter to the batter terminal on the alternator and used a drill to spin the alternator.  It read a volt output of 14-18volts.  I assume all is find with the alternator.

I re-installed the alternator and put the engine back on.  However, the circuit breaker (5amp) trips as soon as the Alt is turned on.  

Is it likely the voltage regulator that has gone bad?  Any ideas?

Thanks,

Corbin Ge!ser


Jim Patillo
 

Corbin,

I run a 60 amp alternator on my 200 like yours.

Is your 50-60 amp alternator circuit breaker
on the firewall or in the cabin? Have you checked to see if it’s tripping early? That sometimes happens with heat when the breaker ages. That in turn can trip the light. You may want to replace it.

BTW, do you still have the black 60/70 Catto Prop on your plane? Did you notice how the front of the hub was tapered down to let the spinner fit. Craig originally made the hub to wide and had to modify it.

Jim

N46JP - Q200


Corbin
 

Hey Jim - hmm, so there’s also a 50-60 amp circuit breaker somewhere as well?  I’ll have to look for that and then follow back up.

Yes, the black Catto prop is still on there.  Good to know about the tapered design!  I didn’t know that.

Thanks,

Corbin

On Jul 29, 2019, at 12:22 AM, logistics_engineering@... [Q-LIST] <Q-LIST@...> wrote:

 

Corbin,

I run a 60 amp alternator on my 200 like yours.

Is your 50-60 amp alternator circuit breaker
on the firewall or in the cabin? Have you checked to see if it’s tripping early? That sometimes happens with heat when the breaker ages. That in turn can trip the light. You may want to replace it.

BTW, do you still have the black 60/70 Catto Prop on your plane? Did you notice how the front of the hub was tapered down to let the spinner fit. Craig originally made the hub to wide and had to modify it.

Jim

N46JP - Q200


Corbin
 

Thanks....I’ve found the manual and will look again for testing tolerances.  If not, I’ll call them now that they are back from Osh.

I would love to charge the battery but have never taken off the tail before and don’t see how I can reach it otherwise.  Easy process to remove tail?

Corbin

On Jul 28, 2019, at 9:38 PM, Jay Scheevel jay@... [Q-LIST] <Q-LIST@...> wrote:

 

Not sure what regulator you currently have, but you can probably Google up the installation manual if you know the make and model. This will tell you how to test it with a voltmeter between different contacts looking for expected values within tolerances. I would also make sure your battery is fully charged before trying start and test amternator again, in order to minimize load on the charging circuit when you flip the field switch on after starting. Good luck trouble shooting.

Cheers,
Jay

Sent from my Verizon Wireless 4G LTE DROID


"Corbin Geiser c_geiser@... [Q-LIST]" <Q-LIST@...> wrote:

 

I am chasing down an alternator related issue and running out of ideas.  During a flight, the Alt Warning bulb started flashing and I noticed a discharge on the Amp gauge.  The Volt gauge was showing 11 volts.  I returned to land and troubleshoot.  I pulled the engine to get the alternator off and I found the rod/spindle had sheared close to the gear.  I got a different alternator and swapped the rod and gear.  I did a bench test by connecting a multimeter to the batter terminal on the alternator and used a drill to spin the alternator.  It read a volt output of 14-18volts.  I assume all is find with the alternator.

I re-installed the alternator and put the engine back on.  However, the circuit breaker (5amp) trips as soon as the Alt is turned on.  

Is it likely the voltage regulator that has gone bad?  Any ideas?

< div>Thanks,

Corbin Ge!ser


Rick Hole
 

The 50/60a breaker protects you from shorted diodes and disconnects the alternator output from the main power bus. The 5a breaker disconnects voltage to the regulator and alternator field. 
If the 5a trips try disconnecting the wire to alternator field. Still trips: you have a bad regulator or wire fault. No trip: alternator problem. 
59/60a trips suggests bad alternator or wire fault between breaker and alternator. 
As you bench tested the alternator, the regulator and it’s wires are more likely the problem. 

Rick Hole
Retired from Velocity


Jim Patillo
 

I’ve had this problem twice with the 5a popping and low voltage light illuminating. Both times the 50-60 amp breaker had failed and that was it. Mine is installed on the engine side of the firewall. We shall see. Just another possibility. 😊

Jim
N46JP - Q200
1660 hrs on my Q


Rick Hole
 

Right on. A simple test is with power on and engine not running check voltage at alternator output, the large wire. You will see battery voltage if right or zero if the output circuit or breaker is open. 

Sonia and Rick Hole
Email: r.hole@...

On Jul 29, 2019, at 7:52 AM, logistics_engineering@... [Q-LIST] <Q-LIST@...> wrote:

 

I’ve had this problem twice with the 5a popping and low voltage light illuminating. Both times the 50-60 amp breaker had failed and that was it. Mine is installed on the engine side of the firewall. We shall see. Just another possibility. 😊

Jim
N46JP - Q200
1660 hrs on my Q


Corbin
 

It would be wonderful if this is my issue as well!   Can't wait to get out there today and look for that 50-60 amp breaker!

Corbin Ge!ser

On July 29, 2019 at 8:52 AM, "logistics_engineering@... [Q-LIST]" wrote:

 

I’ve had this problem twice with the 5a popping and low voltage light illuminating. Both times the 50-60 amp breaker had failed and that was it. Mine is installed on the engine side of the firewall. We shall see. Just another possibility. 😊

Jim
N46JP - Q200
1660 hrs on my Q


Corbin
 

Thanks Jim.  Just to make sure I understand.  Are you saying to turn on Master only or Master and Alt and test voltage from Batt terminal on Alternator?  Reason I ask is because if my Alt field breaker is popping I wouldn't be able to test this way.  Just want to make sure I am doing it right.  Thanks for all the help!

Corbin Ge!ser

On July 29, 2019 at 9:07 AM, "Rick Hole r.hole@... [Q-LIST]" wrote:

 

Right on. A simple test is with power on and engine not running check voltage at alternator output, the large wire. You will see battery voltage if right or zero if the output circuit or breaker is open. 

Sonia and Rick Hole
Email: r.hole@...

On Jul 29, 2019, at 7:52 AM, logistics_engineering@... [Q-LIST] <Q-LIST@...> wrote:

 

I’ve had this problem twice with the 5a popping and low voltage light illuminating. Both times the 50-60 amp breaker had failed and that was it. Mine is installed on the engine side of the firewall. We shall see. Just another possibility. 😊

Jim
N46JP - Q200
1660 hrs on my Q



Mike Dwyer
 

So you need a basic understanding of what is going on here.  The 5A breaker feeds the 'Field" of the alternator.  The Alt switch sends voltage to the regulator which sends voltage to the Field.  The 50 amp breaker is your alternator output.  I can't see how failure of the 50A breaker would affect the 5A breaker.  So here's the deal, with the engine not running, turn on the master and the ALT.  Measure the voltage on the field (this is a small terminal on the back of the Alternator).  Do you have 8-12 volts = good.  Did it blow your 5A breaker= bad.  

So you can spin the alternator, good.  Can you extend wires from the plane and hook to the Alternator.  You need ground, field and the main A+ wire but it can be small cause we're not going to make 60 amps...

Put the voltmeter on the A+ and ground.  should be 12 volts.  Start spinning.  Shouldn't go over 14 volts.  If it does your regulator is bad.  If the A+ stays at 12v when your spinning then go measure the field voltage.  If it's 8-12V then your alternator is bad.  If it's quite low then your regulator is bad.

Happy Hunting,
Mike N3QP Q200


Corbin
 

But if I flip Alt on, the breaker blows so how would I get a good reading off the field terminal?

Corbin

On Jul 29, 2019, at 10:29 AM, q2pilot@... [Q-LIST] <Q-LIST@...> wrote:

 

So you need a basic understanding of what is going on here.  The 5A breaker feeds the 'Field" of the alternator.  The Alt switch sends voltage to the regulator which sends voltage to the Field.  The 50 amp breaker is your alternator output.  I can't see how failure of the 50A breaker would affect the 5A breaker.  So here's the deal, with the engine not running, turn on the master and the ALT.  Measure the voltage on the field (this is a small terminal on the back of the Alternator).  Do you have 8-12 volts = good.  Did it blow your 5A breaker= bad.  


So you can spin the alternator, good.  Can you extend wires from the plane and hook to the Alternator.  You need ground, field and the main A+ wire but it can be small cause we're not going to make 60 amps...

Put the voltmeter on the A+ and ground.  should be 12 volts.  Start spinning.  Shou ldn't go over 14 volts.  If it does your regulator is bad.  If the A+ stays at 12v when your spinning then go measure the field voltage.  If it's 8-12V then your alternator is bad.  If it's quite low then your regulator is bad.

Happy Hunting,
Mike N3QP Q200


Mike Dwyer
 

Ok, great news.

Now disconnect the Field wire from the back of the alternator and leave hanging.
Does the 5A break still blow?  If it does it's a bad regulator.  If it doesn't blow now, then we may have a shorted field in the alternator.
 
: )
Mike


Rick Hole
 

An open alternator output, for example 50a breaker tripped or disconnected wire could cause the field breaker to blow only if the regulator suppling full voltage to the field draws enough current to trip the 5a field breaker. This should not be possible but if the 5a breaker is old and tired and, say, tripping at 3a your could see it trip. I have never seen this happen though. 
Don’t overlook wire fault as a cause, insulation worn through and he wire touching something grounded etc. 

Rick Hole
Email: r.hole@...

On Jul 29, 2019, at 10:23 AM, q2pilot@... [Q-LIST] <Q-LIST@...> wrote:

 

Ok, great news.


Now disconnect the Field wire from the back of the alternator and leave hanging.
Does the 5A break still blow?  If it does it's a bad regulator.  If it doesn't blow now, then we may have a shorted field in the alternator.
 
: )
Mike


Corbin
 

Update:  I’ve located a 50amp breaker labeled MAIN.  I turned on Master, electronics come on, and then I pulled the 50amp breaker.  Nothing turned off.  I’ve removed the breaker and would like to know how to test to confirm if it’s working or not.  

Should all electronics turn off if I pulled the MAIN breaker?

Corbin

On Jul 29, 2019, at 11:59 AM, Rick Hole r.hole@... [Q-LIST] <Q-LIST@...> wrote:

 

An open alternator output, for example 50a breaker tripped or disconnected wire could cause the field breaker to blow only if the regulator suppling full voltage to the field draws enough current to trip the 5a field breaker. This should not be possible but if the 5a breaker is old and tired and, say, tripping at 3a your could see it trip. I have never seen this happen though. 

Don’t overlook wire fault as a cause, insulation worn through and he wire touching something grounded etc. 

Rick Hole
Email: r.hole@...

On Jul 29, 2019, at 10:23 AM, q2pilot@... [Q-LIST] <Q-LIST@...> wrote:

 

Ok, great news.


Now disconnect the Field wire from the back of the alternator and leave hanging.
Does the 5A break still blow?  If it does it's a bad regulator.  If it doesn't blow now, then we may have a shorted field in the alternator.
 
: )
Mike


Jay Scheevel
 

50 amp breaker is handling the current out from the alternator. It is only active when the alternator is spinning otherwise current from the alternator is zero. Battery charge plus electric items is probably 35 amps right after takeoff. If engine is not turning or field voltage is zero, then all current is coming from the battery.

Cheers,
Jay

Sent from my Verizon Wireless 4G LTE DROID


"Corbin Geiser c_geiser@... [Q-LIST]" <Q-LIST@...> wrote:

 

Update:  I’ve located a 50amp breaker labeled MAIN.  I turned on Master, electronics come on, and then I pulled the 50amp breaker.  Nothing turned off.  I’ve removed the breaker and would like to know how to test to confirm if it’s working or not.  


Should all electronics turn off if I pulled the MAIN breaker?

Corbin

On Jul 29, 2019, at 11:59 AM, Rick Hole r.hole@... [Q-LIST] <Q-LIST@...> wrote:

 

An open alternator output, for example 50a breaker tripped or disconnected wire could cause the field breaker to blow only if the regulator suppling full voltage to the field draws enough current to trip the 5a field breaker. This should not be possible but if the 5a breaker is old and tired and, say, tripping at 3a your could see it trip. I have never seen this happen though. 

Don’t overlook wire fault as a cause, insulation worn through and he wire touching something grounded etc. 

Rick Hole
Email: r.hole@...

On Jul 29, 2019, at 10:23 AM, q2pilot@... [Q-LIST] <Q-LIST@...> wrote:

 

Ok, great news.


Now disconnect the Field wire from the back of the alternator and leave hanging.
Does the 5A break still blow?  If it does it's a bad regulator.  If it doesn't blow now, then we may have a shorted field in the alternator.
 
: )
Mike


Rick Hole
 

The easiest test for a functioning alternator is to read the voltage on the 12V bus.  The battery without alternator will be 12.6 volts or less.  A functioning alternator will show more than 12.6 volts.  Normally the voltage regulator will adjust the field current to produce 13.8v with an automotive regulator and possibly as high as 14.4v with an aircraft regulator.

 

The engine must be running for the alternator to produce power, and may not produce full power at less than about 1600 RPMs.

 

Rick Hole

 

From: Q-LIST@... [mailto:Q-LIST@...]
Sent: Monday, July 29, 2019 12:44 PM
To: Q-LIST@...
Subject: Re: [Q-LIST] Re: Alt Field Circuit Breaker Popping

 

 

50 amp breaker is handling the current out from the alternator. It is only active when the alternator is spinning otherwise current from the alternator is zero. Battery charge plus electric items is probably 35 amps right after takeoff. If engine is not turning or field voltage is zero, then all current is coming from the battery.

 

Cheers,

Jay

 

Sent from my Verizon Wireless 4G LTE DROID



"Corbin Geiser c_geiser@... [Q-LIST]" <Q-LIST@...> wrote:

 

Update:  I’ve located a 50amp breaker labeled MAIN.  I turned on Master, electronics come on, and then I pulled the 50amp breaker.  Nothing turned off.  I’ve removed the breaker and would like to know how to test to confirm if it’s working or not.  

 

Should all electronics turn off if I pulled the MAIN breaker?

Corbin


On Jul 29, 2019, at 11:59 AM, Rick Hole r.hole@... [Q-LIST] <Q-LIST@...> wrote:

 

An open alternator output, for example 50a breaker tripped or disconnected wire could cause the field breaker to blow only if the regulator suppling full voltage to the field draws enough current to trip the 5a field breaker. This should not be possible but if the 5a breaker is old and tired and, say, tripping at 3a your could see it trip. I have never seen this happen though. 

Don’t overlook wire fault as a cause, insulation worn through and he wire touching something grounded etc. 

Rick Hole

Email: r.hole@...


On Jul 29, 2019, at 10:23 AM, q2pilot@... [Q-LIST] <Q-LIST@...> wrote:

 

Ok, great news.

 

Now disconnect the Field wire from the back of the alternator and leave hanging.

Does the 5A break still blow?  If it does it's a bad regulator.  If it doesn't blow now, then we may have a shorted field in the alternator.

 

: )

Mike

 


Rick Hole
 

With breaker removed, Measure the resistance across the two terminals.  Breaker in= 0 ohms.  Breaker pulled= infinite ohms.

Ideally you would rig a rest with a DC power source, breaker, and load resistor.  Dial up 50 amps.  The breaker should hold.  Dial up higher, perhaps 60 or 70 amps, the breaker should trip within a minute.  

Or test without disconnecting the breaker.  Engine not running, Turn bus on, breaker button pushed IN.  Read battery voltage on both terminals.  Button pulled, battery voltage only one terminal, 0 volts on the other

 

Rick Hole

 

From: Q-LIST@... [mailto:Q-LIST@...]
Sent: Monday, July 29, 2019 11:30 AM
To: Q-LIST@...
Subject: Re: [Q-LIST] Re: Alt Field Circuit Breaker Popping

 

 

Update:  I’ve located a 50amp breaker labeled MAIN.  I turned on Master, electronics come on, and then I pulled the 50amp breaker.  Nothing turned off.  I’ve removed the breaker and would like to know how to test to confirm if it’s working or not.  

 

Should all electronics turn off if I pulled the MAIN breaker?

Corbin


On Jul 29, 2019, at 11:59 AM, Rick Hole r.hole@... [Q-LIST] <Q-LIST@...> wrote:

 

An open alternator output, for example 50a breaker tripped or disconnected wire could cause the field breaker to blow only if the regulator suppling full voltage to the field draws enough current to trip the 5a field breaker. This should not be possible but if the 5a breaker is old and tired and, say, tripping at 3a your could see it trip. I have never seen this happen though. 

Don’t overlook wire fault as a cause, insulation worn through and he wire touching something grounded etc. 

Rick Hole

Email: r.hole@...


On Jul 29, 2019, at 10:23 AM, q2pilot@... [Q-LIST] <Q-LIST@...> wrote:

 

Ok, great news.

 

Now disconnect the Field wire from the back of the alternator and leave hanging.

Does the 5A break still blow?  If it does it's a bad regulator.  If it doesn't blow now, then we may have a shorted field in the alternator.

 

: )

Mike

 


Corbin
 

Okay, great.....I can ignore that distraction of why it wasn't shutting everything off.  Thanks!

Corbin Ge!ser

On July 29, 2019 at 2:04 PM, "Jay Scheevel jay@... [Q-LIST]" wrote:

 


50 amp breaker is handling the current out from the alternator. It is only active when the alternator is spinning otherwise current from the alternator is zero. Battery charge plus electric items is probably 35 amps right after takeoff. If engine is not turning or field voltage is zero, then all current is coming from the battery.

Cheers,
Jay

Sent from my Verizon Wireless 4G LTE DROID


"Corbin Geiser c_geiser@... [Q-LIST]" wrote:

 

Update:  I’ve located a 50amp breaker labeled MAIN.  I turned on Master, electronics come on, and then I pulled the 50amp breaker.  Nothing turned off.  I’ve removed the breaker and would like to know how to test to confirm if it’s working or not.  


Should all electronics turn off if I pulled the MAIN breaker?

Corbin

On Jul 29, 2019, at 11:59 AM, Rick Hole r.hole@... [Q-LIST] <Q-LIST@...> wrote:

 

An open alternator output, for example 50a breaker tripped or disconnected wire could cause the field breaker to blow only if the regulator suppling full voltage to the field draws enough current to trip the 5a field breaker. This should not be possible but if the 5a breaker is old and tired and, say, tripping at 3a your could see it trip. I have never seen this happen though. 

Don’t overlook wire fault as a cause, insulation worn through and he wire touching something grounded etc. 

Rick Hole
Email: r.hole@...

On Jul 29, 2019, at 10:23 AM, q2pilot@... [Q-LIST] <Q-LIST@...> wrote:

 

Ok, great news.


Now disconnect the Field wire from the back of the alternator and leave hanging.
Does the 5A break still blow?  If it does it's a bad regulator.  If it doesn't blow now, then we may have a shorted field in the alternator.
 
: )
Mike






Corbin
 

This sounds easy to test.....where on bus should I test voltage from?  I am not familiar with working with the bus.  Do I just place the probe anywhere on a good contact along bus?

Corbin Ge!ser

On July 29, 2019 at 2:50 PM, "'Rick Hole' r.hole@... [Q-LIST]" wrote:

 


The easiest test for a functioning alternator is to read the voltage on the 12V bus.  The battery without alternator will be 12.6 volts or less.  A functioning alternator will show more than 12.6 volts.  Normally the voltage regulator will adjust the field current to produce 13.8v with an automotive regulator and possibly as high as 14.4v with an aircraft regulator.

 

The engine must be running for the alternator to produce power, and may not produce full power at less than about 1600 RPMs.

 

Rick Hole

 

From: Q-LIST@... [mailto:Q-LIST@...]
Sent: Monday, July 29, 2019 12:44 PM
To: Q-LIST@...
Subject: Re: [Q-LIST] Re: Alt Field Circuit Breaker Popping

 

 

50 amp breaker is handling the current out from the alternator. It is only active when the alternator is spinning otherwise current from the alternator is zero. Battery charge plus electric items is probably 35 amps right after takeoff. If engine is not turning or field voltage is zero, then all current is coming from the battery.

 

Cheers,

Jay

 

Sent from my Verizon Wireless 4G LTE DROID



"Corbin Geiser c_geiser@... [Q-LIST]" <Q-LIST@...> wrote:

 

Update:  I’ve located a 50amp breaker labeled MAIN.  I turned on Master, electronics come on, and then I pulled the 50amp breaker.  Nothing turned off.  I’ve removed the breaker and would like to know how to test to confirm if it’s working or not.  

 

Should all electronics turn off if I pulled the MAIN breaker?

Corbin


On Jul 29, 2019, at 11:59 AM, Rick Hole r.hole@... [Q-LIST] <Q-LIST@...> wrote:

 

An open alternator output, for example 50a breaker tripped or disconnected wire could cause the field breaker to blow only if the regulator suppling full voltage to the field draws enough current to trip the 5a field breaker. This should not be possible but if the 5a breaker is old and tired and, say, tripping at 3a your could see it trip. I have never seen this happen though. 

Don’t overlook wire fault as a cause, insulation worn through and he wire touching something grounded etc. 

Rick Hole

Email: r.hole@...


On Jul 29, 2019, at 10:23 AM, q2pilot@... [Q-LIST] <Q-LIST@...> wrote:

 

Ok, great news.

 

Now disconnect the Field wire from the back of the alternator and leave hanging.

Does the 5A break still blow?  If it does it's a bad regulator.  If it doesn't blow now, then we may have a shorted field in the alternator.

 

: )

Mike