Matronics Email Lists :: View topic - Reverse flow in Shunt and Hall Effect

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

Reverse flow in Shunt and Hall Effect

Matronics Email Lists Forum Index -> AeroElectric-List

View previous topic :: View next topic

Author Message

Speedy11(at)aol.com
Guest

Posted: Wed Jun 10, 2009 9:22 am Post subject: Reverse flow in Shunt and Hall Effect

I have a HE device on the B lead from the Alternator to the main  battery.  It is oriented so that current is measured from the alternator to  the main battery thus indicating the load imposed on the alternator.

  

 I have a shunt on the standby battery to measure current being used from  the battery.

  

 If current flows in the opposite direction from the planned flow, does one  get a negative amperage indication?

  

 Stan Sutterfield

  Dell Inspiron 15 Laptop: Now in 6 vibrant colors! Shop Dell's full line of laptops.

  [quote][b]

- 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: Wed Jun 10, 2009 6:51 pm Post subject: Reverse flow in Shunt and Hall Effect

At 12:15 PM 6/10/2009, you wrote:

  	  Quote: 	
		   I have a HE device on the B lead from the Alternator to the main battery.  It is oriented so that current is measured from the alternator to the main battery thus indicating the load imposed on the alternator.

  

 I have a shunt on the standby battery to measure current being used from the battery.

  

 If current flows in the opposite direction from the planned flow, does one get a negative amperage indication?

  

 Stan Sutterfield 	


    Probably. But it's dependent upon the display

    software. I've never encountered a system that

    wouldn't show both +/- indications accurately but that

    doesn't mean they don't exist. Chances are your

    indicator will show a value for both charge

    and discharge currents just fine.



 

        Bob . . .



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

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

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



     [quote][b]

- 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

mprather(at)spro.net
Guest

Posted: Wed Jun 10, 2009 7:22 pm Post subject: Reverse flow in Shunt and Hall Effect

Yes..  Current going the opposite direction through the shunt will

generate a negative voltage.  The sensor connected to the shunt should

interpret/display that as a negative current.



One other thought is that a large discharge current is created by

operating the engine starter which will generate a significant negative

voltage across the shunt.  If using a mechanical display it will slap the

needle around pretty hard.  Maybe not a big deal, but something to

consider.  One might install a normally-closed relay in the lead to the

shunt which.  Connect the controlling coil to the starter switch so that

when the starter is engaged, the meter is disabled.  I wouldn't think a

digital display input would have any problems.



If the shunt drops 50mV at full scale alternator output (not an unusual

scheme).  Alternator output might be 50A, and starter current might be

250A, so the shunt might drop 500mV (-0.5V) when operating the starter. 

Round numbers.

Regards,



Matt-



 	  Quote: 	
		   I have a HE device on the B lead from the Alternator to the main  battery.

 It is oriented so that current is measured from the alternator to  the

 main

 battery thus indicating the load imposed on the alternator.



 I have a shunt on the standby battery to measure current being used from

 the battery.



 If current flows in the opposite direction from the planned flow, does one

 get a negative amperage indication?



 Stan Sutterfield

 **************Dell Inspiron 15 Laptop: Now in 6 vibrant colors! Shop

 Dellâ€™s

 full line of laptops.

 =http:%2F%2Fad.doubleclick.net%2Fclk%3B215566094%3B3786435

 8%3Bv)

- 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

Speedy11(at)aol.com
Guest

Posted: Thu Jun 11, 2009 6:11 am Post subject: Reverse flow in Shunt and Hall Effect

Matt and Bob,

 Thanks for your responses.  You've confirmed my understanding of shunt  and HE functions.

 I'm using an Advanced Flt Systems AF-3400 and it reads both devices.   I've had external power (regulated power supply) connected to one battery  and I was getting negative amp indications.  So, with the power supply  connected to the battery and electrical consumers turned on, the shunt/HE will  show a negative amperage.

 I'll be running the engine again in a few days and I'll check to make  sure amps are positive with normal alternator operation.

 Stan

  

  	  Quote: 	
		  Yes..  Current going the opposite direction through the shunt    will

generate a negative voltage.  The sensor connected to the shunt    should

interpret/display that as a negative  current.

	


 

  

 Dell Deals: Don't miss huge summer savings on popular laptops starting at $449.

- 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

JohnInReno

Joined: 08 Sep 2007
Posts: 150

Posted: Thu Jun 11, 2009 8:25 am Post subject: Reverse flow in Shunt and Hall Effect

Speedy11(at)aol.com (Speedy11(at)aol.com) wrote:  	  Quote: 	
		                 I'm using an Advanced Flt Systems AF-3400 and it reads both devices.  I've had external power (regulated power supply) connected to one battery and I was getting negative amp indications.  So, with the power supply connected to the battery and electrical consumers turned on, the shunt/HE will show a negative amperage.

   

   	
 I am just starting the wiring on my AFS 3500 so I am probably confused, but I thought the shunt and Hall Effect were mutually exclusive. I plan to run both alternators (Z13/ through the HE as shown on page 42 of the AF3500 System Manual V5.3. Am I missing something?

 

 John Morgensen

 RV9A - wiring

    [quote][b]

- 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

_________________
John Morgensen
RV-9A - Born on July 3, 2013
RV4 - for sale

Bret Smith

Joined: 09 Jan 2006
Posts: 178
Location: Mineral Bluff, GA

Posted: Thu Jun 11, 2009 9:17 am Post subject: Reverse flow in Shunt and Hall Effect

I'm wired for 13/8 and use the AFS3500's.  I went with two shunts; one  FWF for the main alt and another cabin-side for the SD-8.  I had the  main alt shunt reading negatively at first and only had to reverse the wires to  the AFS unit.

  

 HTH

  

 Bret Smith

RV-9A N16BL

Blue Ridge, GA

www.FlightInnovations.com

 [quote]   ---

- 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

_________________
Bret Smith
RV-9A (Emp)

andrewbutler(at)ireland.c
Guest

Posted: Fri Jun 12, 2009 8:54 am Post subject: Reverse flow in Shunt and Hall Effect

Hi John,



When I received my 3500, I received only the Hall Effect sensor that I ordered extra. I have two power supplies and looking at the manual I figured that the both must go through the HE sensor (there are two wires in the photograph and there was no shunt in the box). Just to make sure I contacted AFS. They said that each power supply should be measured separately, and that the shunt was left out by mistake. They shipped it the same day.



I installed the shunt for the main alt firewall forward (Z13/, with the HE sensor for my SD-8 placed behind the panel just in front of the firewall. Haven't fired up the engine yet though.



Andrew

RV7, EI-EEO

Galway, Ireland.



---

- 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