Matronics Email Lists :: View topic

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

Bus Voltage

Matronics Email Lists Forum Index -> AeroElectric-List

View previous topic :: View next topic

Author Message

Speedy11(at)aol.com
Guest

Posted: Thu Sep 17, 2009 7:39 am Post subject: Bus Voltage

In the comment below, Bob said that the bus (main?) should display 14+  volts.  Mine displays 13.5 with the engine running, 60A Plane Power  alternator on, and normal electrical loads of about 22-24 Amps.  Initial  Amp spike is up to 45 just after start as battery recharges, but volts average  13.5 with occasional spike to 13.7.

 Should the PP alternator be putting out more?  Is it adjustable?

 Stan Sutterfield

  

  	  Quote: 	
		  >   Under what conditions? With the engine running and    the

 	  Quote: 	
		     alternator supporting all the ship's electrical    loads,

   one would expect 14.2 to 14.6 volts on the    bus.

	

	


 

  

 

  [quote][b]

frank.hinde(at)hp.com
Guest

Posted: Thu Sep 17, 2009 8:05 am Post subject: Bus Voltage

Well PP sits at  13.7V continuously (as shown on the Dynon EMS..Then one day I measured the  actual battery voltage and it was over 14V...So I took the highly technal path  and chose to ignore it... But it is a curiosity I'd like to get to the bottom  of one day.

  

  

 Frank



   From: owner-aeroelectric-list-server(at)matronics.com  [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of  Speedy11(at)aol.com

Sent: Thursday, September 17, 2009 8:28  AM

To: aeroelectric-list(at)matronics.com

Subject:  Bus Voltage

 

  In the comment below, Bob said that the bus (main?) should display 14+  volts.  Mine displays 13.5 with the engine running, 60A Plane Power  alternator on, and normal electrical loads of about 22-24 Amps.  Initial  Amp spike is up to 45 just after start as battery recharges, but volts average  13.5 with occasional spike to 13.7.

 Should the PP alternator be putting out more?  Is it adjustable?

 Stan Sutterfield

  

  	  Quote: 	
		  >   Under what    conditions? With the engine running and the

 	  Quote: 	
		     alternator    supporting all the ship's electrical loads,

   one would    expect 14.2 to 14.6 volts on the bus.

	

	


 

  

 

  

[quote]



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

ics.com

.matronics.com/contribution



[b]

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Sep 17, 2009 8:06 am Post subject: Bus Voltage

At 10:27 AM 9/17/2009, you wrote:

  	  Quote: 	
		   In the comment below, Bob said that the bus (main?) should display 14+ volts.  Mine displays 13.5 with the engine running, 60A Plane Power alternator on, and normal electrical loads of about 22-24 Amps.  Initial Amp spike is up to 45 just after start as battery recharges, but volts average 13.5 with occasional spike to 13.7.

 Should the PP alternator be putting out more? 	


   Yes . . . and it MAY be . . .



  	  Quote: 	
		     Is it adjustable? 	


   I don't think so. Plane Power starts with

   a suitable IR alternator core and simply

   modifies it to bring the field supply lead

   to the outside world so that OV protection

   and pilot operated switches have ABSOLUTE,

   LOW-ENERGY control over alternator operations.



   Internal regulators for alternators are

   modern integrated circuits. Its EASY to trim

   their regulation set-points for the design

   goal value during manufacture. 14.2 to 14.6

   volts has been the benchmark window for

   as long as I can remember. I'm not aware

   of any example of user adjustable, internal

   regulators.



   Let's eliminate potential sources of uncertainty.

   First, make sure that the voltmeter you're

   citing agrees with other voltmeters to within

   0.1 volts. Check it against a Fluke instrument

   if you can. Know too that the regulator senses

   voltage at the b-lead terminal . . . so it's

   possible that system loads combined with system

   wiring resistance between b-lead and your voltmeter's

   sense point may be accounting for your observation.

   GROUND systems can contribute to a voltage drop

   too.



   Do a voltage measurement right at the b-lead

   terminal reference to the alternator's case

   ground. The alternator may be performing as

   advertised with the voltage being tossed off

   in installation errors.



   Check with Plane Power. Ask them what their

   design-goal set-point value is. Just because

   I've never seen a 13.8v regulator doesn't mean

   they don't exist.



 

        Bob . . .



         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------



     [quote][b]

tim2542(at)sbcglobal.net
Guest

Posted: Thu Sep 17, 2009 3:10 pm Post subject: Bus Voltage

I think this answers a question I had about PP alternators, which is are the regulators linear like B&C?  I gather they are not but still wondering if it is really that important. Nobody seems to be having trouble with noise from them.

 Tim Andres



 

   From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>

To: aeroelectric-list(at)matronics.com

Sent: Thursday, September 17, 2009 9:04:43 AM

Subject: Re: AeroElectric-List: Bus Voltage



At 10:27 AM 9/17/2009, you wrote:

  	  Quote: 	
		  In the comment below, Bob said that the bus (main?) should display 14+ volts.  Mine displays 13.5 with the engine running, 60A Plane Power alternator on, and normal electrical loads of about 22-24 Amps.  Initial Amp spike is up to 45 just after start as battery recharges, but volts average 13.5 with occasional spike to 13.7.

Should the PP alternator be putting out more? 	


  Yes . . . and it MAY be . . .



  	  Quote: 	
		    Is it adjustable? 	


  I don't think so. Plane Power starts with

  a suitable IR alternator core and simply

  modifies it to bring the field supply lead

  to the outside world so that OV protection

  and pilot operated switches have ABSOLUTE,

  LOW-ENERGY control over alternator operations.



  Internal regulators for alternators are

  modern integrated circuits. Its EASY to trim

  their regulation set-points for the design

  goal value during manufacture. 14.2 to 14.6

  volts has been the benchmark window for

  as long as I can remember. I'm not aware

  of any example of user adjustable, internal

  regulators.



  Let's eliminate potential sources of uncertainty.

  First, make sure that the voltmeter you're

   citing agrees with other voltmeters to within

  0.1 volts. Check it against a Fluke instrument

  if you can. Know too that the regulator senses

  voltage at the b-lead terminal . . . so it's

  possible that system loads combined with system

  wiring resistance between b-lead and your voltmeter's

  sense point may be accounting for your observation.

  GROUND systems can contribute to a voltage drop

  too.



  Do a voltage measurement right at the b-lead

  terminal reference to the alternator's case

  ground. The alternator may be performing as

  advertised with the voltage being tossed off

  in installation errors.



  Check with Plane Power. Ask them what their

  design-goal set-point value is. Just because

  I've never seen a 13.8v regulator doesn't mean

  they don't exist.



 

       Bob . . .



        ---------------------------------------

       ( . . .  a long habit of not thinking   )

       ( a thing wrong, gives it a superficial )

       ( appearance of being right . . .       )

       (                                       )

       (                  -Thomas Paine 1776-  )

         ---------------------------------------



 	  Quote: 	
		  http://www.matronics.com/Navigator?AeroElectric-Li======== 

==========

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Thu Sep 17, 2009 4:12 pm Post subject: Bus Voltage

Plane power offers a number of different alternators, including PMA'd 

versions for certified aircraft, that clearly require the original 

external regulator. Their experimental versions are the internally 

regulated models. So you can have pretty much which flavor pleases you.

Tim Andres wrote:

 	  Quote: 	
		   I think this answers a question I had about PP alternators, which is are 

 the regulators linear like B&C?  I gather they are not but still 

 wondering if it is really that important. Nobody seems to be having 

 trouble with noise from them.

 Tim Andres

 ------------------------------------------------------------------------

 *From:* "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>

 *To:* aeroelectric-list(at)matronics.com

 *Sent:* Thursday, September 17, 2009 9:04:43 AM

 *Subject:* Re: Bus Voltage

 At 10:27 AM 9/17/2009, you wrote:

> In the comment below, Bob said that the bus (main?) should display 14+ 

> volts.  Mine displays 13.5 with the engine running, 60A Plane Power 

> alternator on, and normal electrical loads of about 22-24 Amps.  

> Initial Amp spike is up to 45 just after start as battery recharges, 

> but volts average 13.5 with occasional spike to 13.7.

> Should the PP alternator be putting out more?

   Yes . . . and it MAY be . . .

>   Is it adjustable?

   I don't think so. Plane Power starts with

   a suitable IR alternator core and simply

   modifies it to bring the field supply lead

   to the outside world so that OV protection

   and pilot operated switches have ABSOLUTE,

   LOW-ENERGY control over alternator operations.

   Internal regulators for alternators are

   modern integrated circuits. Its EASY to trim

   their regulation set-points for the design

   goal value during manufacture. 14.2 to 14.6

   volts has been the benchmark window for

   as long as I can remember. I'm not aware

   of any example of user adjustable, internal

   regulators.

   Let's eliminate potential sources of uncertainty.

   First, make sure that the voltmeter you're

   citing agrees with other voltmeters to within

   0.1 volts. Check it against a Fluke instrument

   if you can. Know too that the regulator senses

   voltage at the b-lead terminal . . . so it's

   possible that system loads combined with system

   wiring resistance between b-lead and your voltmeter's

   sense point may be accounting for your observation.

   GROUND systems can contribute to a voltage drop

   too.

   Do a voltage measurement right at the b-lead

   terminal reference to the alternator's case

   ground. The alternator may be performing as

   advertised with the voltage being tossed off

   in installation errors.

   Check with Plane Power. Ask them what their

   design-goal set-point value is. Just because

   I've never seen a 13.8v regulator doesn't mean

   they don't exist.

        Bob . . .

         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------

 *http://www.matronics.com/Navigator?AeroElectric-Li======== 

 ==========    *

 *

 *

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

tim2542(at)sbcglobal.net
Guest

Posted: Thu Sep 17, 2009 4:58 pm Post subject: Bus Voltage

Thanks but the question is are the PP regulators linear or switchers?



---

nuckolls.bob(at)aeroelect
Guest

Posted: Fri Sep 18, 2009 5:40 am Post subject: Bus Voltage

At 07:49 PM 9/17/2009, you wrote:

 	  Quote: 	
		  



Thanks but the question is are the PP regulators linear or switchers?


	


  If they're internal, then they are duty-cycle switched.

  External can be either but linears are very rare. Probably

  less than 5% of the total market. As it turns out, all

  the excitement we had about 20 years ago for noise

  reduction by "going linear" was not well founded in

  physics. There's no reason for switchers . . . especially

  those that are built in . . . to be significant noise

  sources.



  Moral: don't shy away from switchers 'cause they're

  "quieter" . . .

        Bob . . .



         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------

chasb(at)satx.rr.com
Guest

Posted: Fri Sep 18, 2009 8:49 am Post subject: Bus Voltage

With reference to the bus voltage discussion below:



I have a B&C 55 amp alternator with a generic Ford regulator. The Ford regulator is bench adjustable and I had it set to 14.2 volts. My voltage sensing set up measures system voltage from the endurance bus and, under normal conditions, reads a steady 13.7 volts. Under normal (main bus) operation, the endurance bus gets its power via the main bus through a diode resulting in a measurable voltage drop. Switching to the endurance bus, power is provided directly to the endurance bus from the battery contactor and the voltage then reads a steady 14.2 volts.  I can detect no change in avionics and instruments performance regardless of the bus used. 

In the situation cited below, system voltage may read low depending on where in the system the voltage is measured.

Charlie Brame

RV-6A N11CB

San Anton

--------------------------------------------------------



Time: 09:06:32 AM PST US

From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)>

Subject: Re: Bus Voltage



At 10:27 AM 9/17/2009, you wrote:

 	  Quote: 	
		  In the comment below, Bob said that the bus (main?) should display 

14+ volts.  Mine displays 13.5 with the engine running, 60A Plane 

Power alternator on, and normal electrical loads of about 22-24 

Amps.  Initial Amp spike is up to 45 just after start as battery 

recharges, but volts average 13.5 with occasional spike to 13.7.

Should the PP alternator be putting out more?

	


  Yes . . . and it MAY be . . .



 	  Quote: 	
		   Is it adjustable?

	


  I don't think so. Plane Power starts with

  a suitable IR alternator core and simply

  modifies it to bring the field supply lead

  to the outside world so that OV protection

  and pilot operated switches have ABSOLUTE,

  LOW-ENERGY control over alternator operations.



  Internal regulators for alternators are

  modern integrated circuits. Its EASY to trim

  their regulation set-points for the design

  goal value during manufacture. 14.2 to 14.6

  volts has been the benchmark window for

  as long as I can remember. I'm not aware

  of any example of user adjustable, internal

  regulators.



  Let's eliminate potential sources of uncertainty.

  First, make sure that the voltmeter you're

  citing agrees with other voltmeters to within

  0.1 volts. Check it against a Fluke instrument

  if you can. Know too that the regulator senses

  voltage at the b-lead terminal . . . so it's

  possible that system loads combined with system

  wiring resistance between b-lead and your voltmeter's

  sense point may be accounting for your observation.

  GROUND systems can contribute to a voltage drop

  too.



  Do a voltage measurement right at the b-lead

  terminal reference to the alternator's case

  ground. The alternator may be performing as

  advertised with the voltage being tossed off

  in installation errors.



  Check with Plane Power. Ask them what their

  design-goal set-point value is. Just because

  I've never seen a 13.8v regulator doesn't mean

  they don't exist.

       Bob . . .



 [quote][b]

nuckolls.bob(at)aeroelect
Guest

Posted: Fri Sep 18, 2009 5:20 pm Post subject: Bus Voltage

At 11:36 AM 9/18/2009, you wrote:

 	  Quote: 	
		  With reference to the bus voltage discussion below:



I have a B&C 55 amp alternator with a generic Ford regulator. The 

Ford regulator is bench adjustable and I had it set to 14.2 volts. 

My voltage sensing set up measures system voltage from the endurance 

bus and, under normal conditions, reads a steady 13.7 volts. Under 

normal (main bus) operation, the endurance bus gets its power via 

the main bus through a diode resulting in a measurable voltage drop. 

Switching to the endurance bus, power is provided directly to the 

endurance bus from the battery contactor and the voltage then reads 

a steady 14.2 volts.  I can detect no change in avionics and 

instruments performance regardless of the bus used.


	


   Those readings are "as expected" and conform to design

   goals.

 	  Quote: 	
		  In the situation cited below, system voltage may read low depending 

on where in the system the voltage is measured.


	


   Agreed.



   Once the energy leaves the alternator, the ONLY thing

   that can contribute to voltage drops is wire sizing

   versus loads on those wires . . . and (to a lesser extent)

   resistances that pile up in the sum-total of pressure

   joints.  If the battery is measuring 14.2 to 14.6 then

   the alternator is doing it's job and the battery gets

   100% topped off. Wire between the alternator and battery

   is always "fat" wires. After that, any unacceptable losses

   in available voltage MUST be from errors of design or

   installation.

        Bob . . .



         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------

user9253

Joined: 28 Mar 2008
Posts: 1921
Location: Riley TWP Michigan

Posted: Fri Sep 18, 2009 7:45 pm Post subject: Bus Voltage

Stan,

 A good test is to compare the bus voltage with  light loads to the bus voltage with heavy loads.  If there is a big  difference, then there is a lot of resistance in the circuit, possibly from too  small wire or from bad connections.

 Joe

   [quote][b]

_________________
Joe Gores

Speedy11(at)aol.com
Guest

Posted: Sat Sep 19, 2009 10:50 am Post subject: Bus Voltage

Joe,

 Thanks for your comment.

 I have taken notice of the voltage during light and heaviest loads and it  remains steady at 13.5.  The light loading was about 3 Amps and heavy was  about 32A (everything on).

 So, I'll take readings as Bob suggested and see what I find.

 Stan

  	  Quote: 	
		  Stan,

A good test is to compare the bus voltage with light loads to    the bus 

voltage with heavy loads.  If there is a big difference, then    there is a 

lot of resistance in the circuit, possibly from too small wire    or from 

bad connections.

Joe

	


 

  

  [quote][b]

Speedy11(at)aol.com
Guest

Posted: Mon Sep 21, 2009 9:52 am Post subject: Bus Voltage

Joe,

 I took careful notice of the bus voltage yesterday as I loaded up the bus  and you've brought up a good point.  At an 8 amp load, the bus voltage was  13.5.  At 29 amps it dropped to 13.2 and stayed there until I reduced the  load.  So, I must have too small a wire from the alternator to the  bus.  I'll consider changing it.

 Thanks,

 Stan Sutterfield

  

  	  Quote: 	
		     Joe,

   Thanks for your comment.

   I have taken notice of the voltage during light and heaviest loads and it    remains steady at 13.5.  The light loading was about 3 Amps and heavy was    about 32A (everything on).

   So, I'll take readings as Bob suggested and see what I find.

   Stan

    	  Quote: 	
		  Stan,

A good test is to compare the bus voltage with light loads      to the bus 

voltage with heavy loads.  If there is a big difference,      then there is a 

lot of resistance in the circuit, possibly from too      small wire or from 

bad  connections.

Joe

	
	


 

  

  [quote][b]

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