Matronics Email Lists :: View topic - Over Voltage on Start Up

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Over Voltage on Start Up

Matronics Email Lists Forum Index -> AeroElectric-List

View previous topic :: View next topic

Author Message

dbarnes

Joined: 31 Aug 2013
Posts: 3

Posted: Sun Sep 01, 2013 11:17 am Post subject: Over Voltage on Start Up

I have 40 hours on my lancair es and have been trying to solve a charging problem since the first startup in july.  I have a vertical power electrical system (vp-200), a b&c voltage regulator (lr3c) and an io-550n with a stock 60 amp alternator.  Five seconds after engine start vertical power switches power on to the voltage regulator.  The alternator comes on and vertical power senses an overvoltage and disconnects the power to the regulator.  After resetting the vertical power sometimes two or three times over a 30 second time period the system holds and remains fine for the balance of the flight.



I replaced the voltage regulator with an identical replacement with no change.  Another clue is that when the system first starts holding in the voltage is on the high side close to 31 volts. Over time maybe ten minutes it settles down to 28.6 for the remaining flight.  I also hear a faint alternator squeal in my headset.  I am using two odyssey pc535 12 volt batteries in series and they are at the rear of the plane connected with #2 welding cable



The odyssey batteries are four years old but have been kept charged with a smart charger. I wondered whether a bad diode in the alternator could cause this?



Anyone have any ideas?



Thanks,

Dan Barnes

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Sep 01, 2013 12:59 pm Post subject: Over Voltage on Start Up

I have 40 hours on my lancair es and have been trying to solve a 

charging problem since the first startup in july.  I have a vertical 

power electrical system (vp-200), a b&c voltage regulator (lr3c) and 

an io-550n with a stock 60 amp alternator.  Five seconds after engine 

start vertical power switches power on to the voltage regulator.  The 

alternator comes on and vertical power senses an overvoltage and 

disconnects the power to the regulator.  After resetting the vertical 

power sometimes two or three times over a 30 second time period the 

system holds and remains fine for the balance of the flight.



I replaced the voltage regulator with an identical replacement with 

no change.  Another clue is that when the system first starts holding 

in the voltage is on the high side close to 31 volts.



   There's something fundamentally wrong here. The voltage

   should NEVER be higher than the regulator's set-point.

   Readings of 31 volts suggests that the regulator is not

   getting 'real' bus voltage sample which is critical to

   proper operation.



   Attach a (+) lead of a voltmeter to the regulator's bus

   voltage sense terminal (#3) and the (-) lead to regulator

   ground terminal (#7).  Tell us what you read when the

   VP screen is reporting 31 volts.  It sounds like the

   regulator 'believes' it's doing a good thing while in

   fact, the data it's operating on is bogus.



   How is the regulator grounded?



   Where does terminal (#3) get it's power?



Over time maybe ten minutes it settles down to 28.6  for the 

remaining flight.  I also hear a faint alternator squeal in 

my      headset.  I am using two odyssey pc535 12 volt batteries in 

series and they are at the rear of the plane connected with #2 welding cable



   This has the 'smell' of a grounding issue where battery

   recharge currents are polluting the regulator's ground

   reference causing it to operate at something other than the

   set-point.



   Try dismounting the regulator, disconnect existing wire

   from terminal #7 and run a test wire from #7 to the

   crankcase. I'm thinking that you may see the ov

   condition disappear. Can you describe your ground system

   for us?

   Bob . . .

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

dbarnes

Joined: 31 Aug 2013
Posts: 3

Posted: Mon Sep 02, 2013 8:14 am Post subject: Re: Over Voltage on Start Up

Starting at the battery a #2 cable goes to the inside of the fire wall to a plate with a field of spade connectors then through a 5/16 inch brass bolt to the engine side of the firewall to another field of spade connectors and also to one of the starter mounting bolts through a large braided cable.  The regulator is on the engine side of the firewall and gets its ground from one of the spade connectors.  Originally I had the sense line of the regulator hooked to a dedicated output from vertical power.  In trying to solve this problem I moved it to the battery positive bolt on the firewall (through a small fuse).  At first it seemed to solve the problem but the charging voltage was too low.  When I adjusted higher I was back to the same problem.



I am going to the hanger this pm and will try an alternate ground to the engine block and extend wires into the plane to measure the sense voltage and compare it to the vp displayed voltage.



Thanks,

Dan Barnes

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

nuckolls.bob(at)aeroelect
Guest

Posted: Tue Sep 03, 2013 7:26 am Post subject: Over Voltage on Start Up

At 11:15 AM 9/2/2013, you wrote:

 	  Quote: 	
		  



Starting at the battery a #2 cable goes to the inside of the fire 

wall to a plate with a field of spade connectors then through a 5/16 

inch brass bolt to the engine side of the firewall to another field 

of spade connectors and also to one of the starter mounting bolts 

through a large braided cable.  The regulator is on the engine side 

of the firewall and gets its ground from one of the spade 

connectors.  Originally I had the sense line of the regulator hooked 

to a dedicated output from vertical power.  In trying to solve this 

problem I moved it to the battery positive bolt on the firewall 

(through a small fuse).  At first it seemed to solve the problem but 

the charging voltage was too low.  When I adjusted higher I was back 

to the same problem.



I am going to the hanger this pm and will try an alternate ground to 

the engine block and extend wires into the plane to measure the 

sense voltage and compare it to the vp displayed voltage.


	


    Very good. Your ground system appears righteous. But

    there's something going on that confuses or fools

    the regulator's otherwise clear view of the universe.



   Bob . . .

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

dbarnes

Joined: 31 Aug 2013
Posts: 3

Posted: Tue Sep 03, 2013 9:11 am Post subject: Re: Over Voltage on Start Up

Bob,



I tested the voltage on the sense terminal to the ground terminal on the regulator.  It seemed to match the display on the vertical power.  They both measured over 30 volts.  The io-550 uses a direct drive alternator.  I didn't have an additional ground wire on it so I added that.  I took a #8 wire from the case ground to the engine block.  Another plane I looked at had that so I added it.  No change.  Any chance the regulator is seeing too much ac from the alternator and it is confusing it? I have read in the car world that leaky, open, shorted diodes sometimes cause strange problems.



Thanks,

Dan Barnes

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

nuckolls.bob(at)aeroelect
Guest

Posted: Fri Sep 13, 2013 11:10 am Post subject: Over Voltage on Start Up

I have 40 hours on my lancair es and have been trying to solve a 

charging problem since the first startup in july.  I have a vertical 

power electrical system (vp-200), a b&c voltage regulator (lr3c) and 

an io-550n with a stock 60 amp alternator.  Five seconds after engine 

start vertical power switches power on to the voltage regulator.  The 

alternator comes on and vertical power senses an overvoltage and 

disconnects the power to the regulator.  After resetting the vertical 

power sometimes two or three times over a 30 second time period the 

system holds and remains fine for the balance of the flight.



I replaced the voltage regulator with an identical replacement with 

no change.  Another clue is that when the system first starts holding 

in the voltage is on the high side close to 31 volts.



   There's something fundamentally wrong here. The voltage

   should NEVER be higher than the regulator's set-point.

   Readings of 31 volts suggests that the regulator is not

   getting 'real' bus voltage sample which is critical to

   proper operation.



   Attach a (+) lead of a voltmeter to the regulator's bus

   voltage sense terminal (#3) and the (-) lead to regulator

   ground terminal (#7).  Tell us what you read when the

   VP screen is reporting 31 volts.  It sounds like the

   regulator 'believes' it's doing a good thing while in

   fact, the data it's operating on is bogus.



   How is the regulator grounded?



   Where does terminal (#3) get it's power?



Over time maybe ten minutes it settles down to 28.6  for the 

remaining flight.  I also hear a faint alternator squeal in 

my      headset.  I am using two odyssey pc535 12 volt batteries in 

series and they are at the rear of the plane connected with #2 welding cable



   This has the 'smell' of a grounding issue where battery

   recharge currents are polluting the regulator's ground

   reference causing it to operate at something other than the

   set-point.



   Try dismounting the regulator, disconnect existing wire

   from terminal #7 and run a test wire from #7 to the

   crankcase. I'm thinking that you may see the ov

   condition disappear. Can you describe your ground system

   for us?

   Bob . . .

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

Display posts from previous:

	Matronics Email Lists Forum Index -> AeroElectric-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum