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Voltage reading of 25V

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kheindl(at)msn.com
Guest

Posted: Wed Jul 28, 2010 11:23 am Post subject: Voltage reading of 25V

 

 This one is for you electric specialists:

  

 All I did was to move the battery back to the firewall from the rear fuselage. I fire up the engine for a highspeed taxi test for my MG configuration and I get a voltage reading of 25.

 I swapped regulators - I always carry a spare  - but no change. I also get the same reading with the alternator switched off. What could I possibly have screwed up ? 

 To make things even more perplexing, the oil pressure indication does not drop below 93, as the engine is warming up, but maybe the two are somehow related. All readings are from the EIS. Never had a problem like this before. 

 Any help appreciated.

 Thanks,    Karl

 

 		 	   		    [quote][b]

rampil

Joined: 04 May 2007
Posts: 870

Posted: Wed Jul 28, 2010 3:31 pm Post subject: Re: Voltage reading of 25V

sounds like a bad ground!

_________________
Ira N224XS

budyerly(at)msn.com
Guest

Posted: Wed Jul 28, 2010 3:37 pm Post subject: Voltage reading of 25V

<?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->  Karl,

 Not knowing your bus wiring,

 Do you have a spare / backup battery, and if so did it accidentally get  wired in series?

 Double the voltage and a higher than normal voltage to the sender tends to  drive the pressure up and temps down (I think, I may have to do some  research as I may have that backwards.)

  

  I know, dumb question, but I thought I'd ask.



 Bud

 [quote]   ---

kheindl(at)msn.com
Guest

Posted: Wed Jul 28, 2010 5:22 pm Post subject: Voltage reading of 25V

Hi Bud,

  

 Good try. There are other small batteries, but they are totally isolated, some 9 volts for variometer and stall warners, and a small 12V for an exterior alarm (to scare animals off the runway or warn pedestrians when taxiing etc.). 

 I merely reconnected the battery leads to the two posts which I have on top of the starboard footwell. I must  have caused a short or ground somehow, but I just don't see it.

 The engine starts and is running fine, but I only let it run for a minute or so.

  

 Karl

 



  

  From: budyerly(at)msn.com

To: europa-list(at)matronics.com

Subject: Re: Europa-List: Voltage reading of 25V

Date: Wed, 28 Jul 2010 19:37:03 -0400



   .ExternalClass .ecxhmmessage P {padding-bottom:0px;padding-left:0px;padding-right:0px;padding-top:0px;} .ExternalClass BODY.ecxhmmessage {font-family:Tahoma;font-size:10pt;}    Karl,

 Not knowing your bus wiring,

 Do you have a spare / backup battery, and if so did it accidentally get wired in series?

 Double the voltage and a higher than normal voltage to the sender tends to drive the pressure up and temps down (I think, I may have to do some research as I may have that backwards.)

  

  I know, dumb question, but I thought I'd ask.



 Bud

 [quote] ---

gregoryf.flyboy(at)comcas
Guest

Posted: Wed Jul 28, 2010 9:04 pm Post subject: Voltage reading of 25V

Hmm..Not sure,

  

 My first thought was along the line of what Ira had said..bad ground  somewhere.

  

  Try making some measurements between the power and ground rails  with a handheld meter to confirm what the EIS was reading. Take the measurements  with the key on and the engine off, to eliminate all chance of actually  producing deadly avionics voltages from a spinning alternator. What is the EIS  reading in this configuration(engine off)? Could there be something that was  connected to the rear-ward wiring that became disconnected when moving the  battery up front? Is the ground strap to the engine block still  connected?

  

 Greg



   From: owner-europa-list-server(at)matronics.com  [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Karl  Heindl

Sent: Wednesday, July 28, 2010 12:23 PM

To:  europa-list(at)matronics.com

Subject: Voltage reading of  25V

 

 

This one is for you electric specialists:

 

All  I did was to move the battery back to the firewall from the rear fuselage. I  fire up the engine for a highspeed taxi test for my MG configuration and I get a  voltage reading of 25.

I swapped regulators - I always carry a spare  -  but no change. I also get the same reading with the alternator switched off.  What could I possibly have screwed up ? 

To make things even more perplexing,  the oil pressure indication does not drop below 93, as the engine is warming up,  but maybe the two are somehow related. All readings are from the EIS. Never had  a problem like this before. 

Any help  appreciated.

Thanks,    Karl

 

[quote]



href="http://www.matronics.com/Navigator?Europa-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com

href="http://www.matronics.com/contribution">http://www.matronics.com/c

[b]

kheindl(at)msn.com
Guest

Posted: Thu Jul 29, 2010 1:29 pm Post subject: Voltage reading of 25V

Greg,

  

 The problem is with the EIS, only why did it coincide with a battery move ?

  

 I checked the voltage in the panel and everything looks fine with the main system. 

  

 The EIS gives good readings with the engine off. Thde only anomaly is the voltage which says 11.0, when it should be 12.5.

 When I start the engine the readings go haywire: oil temp is below of what is possible, pressure is 99, cht is 900C. After switching the EIS off and on a few times the readings are good. But then the numbers start bouncing around again. Of course Grand Rapids are closed for Oshkosh until Monday, and I am not sure what to do.

 Any other ideas ?

  

 Karl 

 



  

  From: gregoryf.flyboy(at)comcast.net

To: europa-list(at)matronics.com

Subject: RE: Voltage reading of 25V

Date: Wed, 28 Jul 2010 22:02:43 -0700



   .ExternalClass .ecxhmmessage P {padding-bottom:0px;padding-left:0px;padding-right:0px;padding-top:0px;} .ExternalClass BODY.ecxhmmessage {font-family:Tahoma;font-size:10pt;}   Hmm..Not sure,

  

 My first thought was along the line of what Ira had said..bad ground somewhere.

  

  Try making some measurements between the power and ground rails with a handheld meter to confirm what the EIS was reading. Take the measurements with the key on and the engine off, to eliminate all chance of actually producing deadly avionics voltages from a spinning alternator. What is the EIS reading in this configuration(engine off)? Could there be something that was connected to the rear-ward wiring that became disconnected when moving the battery up front? Is the ground strap to the engine block still connected?

  

 Greg



   From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Karl Heindl

Sent: Wednesday, July 28, 2010 12:23 PM

To: europa-list(at)matronics.com

Subject: Voltage reading of 25V

 

 

This one is for you electric specialists:

 

All I did was to move the battery back to the firewall from the rear fuselage. I fire up the engine for a highspeed taxi test for my MG configuration and I get a voltage reading of 25.

I swapped regulators - I always carry a spare  - but no change. I also get the same reading with the alternator switched off. What could I possibly have screwed up ? 

To make things even more perplexing, the oil pressure indication does not drop below 93, as the engine is warming up, but maybe the two are somehow related. All readings are from the EIS. Never had a problem like this before. 

Any help appreciated.

Thanks,    Karl

 

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[b]

gregoryf.flyboy(at)comcas
Guest

Posted: Thu Jul 29, 2010 3:19 pm Post subject: Voltage reading of 25V

Karl,

 >The  problem is with the EIS, only why did it coincide with a battery move  ?

 It shouldn't, unless  something else changed.

  

 Ok, so the focus is on the Grand Rapids unit. I don't know much about  the unit itself. What is the model number? Could you steer me to information on it, so  that I might find out more about it?

Not knowing anything about the GR  unit, here are some general ideas (all measurements taken with the  engine off and master on). 

  

 1.     Check supply voltage and ground  connections to the remote measuring system (if there is one). You know,  the box that sometimes exists under the cowl with all the sensor wires  running to it.

  

 2.     Check supply voltage and ground  connections to the EIS unit, itself.

  

 3.    Check if there are any 'sense' lines that need  to be connected that have become open. (Leave this one for later, until after  looking at the units documentation).

  

 #1 and 2 above can be checked with a handheld meter set to volts. Red  probe to (+ supply) and Black probe to (- supply) on the EIS and repeated for  remote measuring box.

  

 If all is ok so far, you can now check that the ground and power  connections are valid and stable, i.e.. not getting partial power or a partial  ground through another device that isn't the battery. 

 1a. Verifying that the ground is stable and valid:  Black  probe on handheld meter(set to volts) to the battery ground post. Red probe  to the negative supply (GND) on the EIS. Repeat for the box under the  cowl.

 Both readings should effectively be zero. If not, it will show a  connection problem to the ground of the unit.

  

 2a.  Verify  positive Supply is stable and valid. Red  probe on handheld to the battery positive terminal. Black probe on the handheld  to the VCC/Supply on the remote measuring box.

 Repeat for EIS. Again, both readings should effectively be zero,  since a zero reading will show up the correct connection to the battery  (readings taken across the wire).  Any measurements producing more  than a few millivolts (maybe 10's of millivolts) are suspect. If invalid reading, it will show a bad supply  connection.

  

 Note that if the voltage measurements in #1 and #2 gave the full  battery voltage, then 1a and 2a will probably be zero, unless something is  changing dynamically.

  

 I hope some of this makes sense, 

 Greg

  

 P.S. Is the old battery ground wire separate from the new ground  wire?  If they are not connected to each other but still in place, try  shorting the two together to see if the readings go back to normal. NOT +  to - or VCC to ground for goodness sakes, unless you want to see a lot of  sparks! Just connect new ground to the old ground, and the new vcc to the old  vcc.  You might try this one first, since it is easier. If the old battery  wires are taken out, then never mind.



   From: owner-europa-list-server(at)matronics.com  [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Karl  Heindl

Sent: Thursday, July 29, 2010 2:28 PM

To:  europa-list(at)matronics.com

Subject: RE: Voltage reading of  25V

 

Greg,

 

The problem is with the EIS, only why did it  coincide with a battery move ?

 

I checked the voltage in the panel  and everything looks fine with the main system. 

 

The EIS gives good  readings with the engine off. Thde only anomaly is the voltage which says 11.0,  when it should be 12.5.

When I start the engine the readings go haywire: oil  temp is below of what is possible, pressure is 99, cht is 900C. After switching  the EIS off and on a few times the readings are good. But then the numbers start  bouncing around again. Of course Grand Rapids are closed for Oshkosh until  Monday, and I am not sure what to do.

Any other ideas  ?

 

Karl 

[quote] [b]

kheindl(at)msn.com
Guest

Posted: Thu Jul 29, 2010 6:41 pm Post subject: Voltage reading of 25V

Thank you for spending so much time on my problem, Gary. I will try and make the suggested measurements. I have another little problem in that I can't find my documentation. I will have a good search tomorrow, and maybe get it off the internet.

 The unit is a EIS 2000, installed around 2000. It never gave a problem. Judging by the symptons it looks like a loose connection or broken wire. It would also explain why it is acting up especially when the engine is running with a little vibration.

 The EIS cable with multipin connector ends in a box on the front of the firewall, so access should be no problem. The old battery cables, which were actually new Perihelion

 4 gauge aluminum , were completely removed, and I made up two new very short leads from the same material.

  

 Cheers,   Karl 

 



  

  From: gregoryf.flyboy(at)comcast.net

To: europa-list(at)matronics.com

Subject: RE: Voltage reading of 25V

Date: Thu, 29 Jul 2010 16:16:17 -0700



   .ExternalClass .ecxhmmessage P {padding-bottom:0px;padding-left:0px;padding-right:0px;padding-top:0px;} .ExternalClass BODY.ecxhmmessage {font-family:Tahoma;font-size:10pt;}   Karl,

 >The problem is with the EIS, only why did it coincide with a battery move ?

 It shouldn't, unless something else changed.

  

 Ok, so the focus is on the Grand Rapids unit. I don't know much about the unit itself.  What is the model number? Could you steer me to information on it, so that I might find out more about it?

Not knowing anything about the GR unit, here are some general ideas (all measurements taken with the engine off and master on). 

  

 1.     Check supply voltage and ground connections to the remote measuring system (if there is one). You know, the box that sometimes exists under the cowl with all the sensor wires running to it.

  

 2.     Check supply voltage and ground connections to the EIS unit, itself.

  

 3.    Check if there are any 'sense' lines that need to be connected that have become open. (Leave this one for later, until after looking at the units documentation).

  

 #1 and 2 above can be checked with a handheld meter set to volts. Red probe to (+ supply) and Black probe to (- supply) on the EIS and repeated for remote measuring box.

  

 If all is ok so far, you can now check that the ground and power connections are valid and stable, i.e.. not getting partial power or a partial ground through another device that isn't the battery. 

 1a. Verifying that the ground is stable and valid:  Black probe on handheld meter(set to volts) to the battery ground post. Red probe to the negative supply (GND) on the EIS. Repeat for the box under the cowl.

 Both readings should effectively be zero. If not, it will show a connection problem to the ground of the unit.

  

 2a.  Verify  positive Supply is stable and valid. Red probe on handheld to the battery positive terminal. Black probe on the handheld to the VCC/Supply on the remote measuring box.

 Repeat for EIS. Again, both readings should effectively be zero, since a zero reading will show up the correct connection to the battery (readings taken across the wire).  Any measurements producing more than a few millivolts (maybe 10's of millivolts) are suspect. If invalid reading, it will show a bad supply connection.

  

 Note that if the voltage measurements in #1 and #2 gave the full battery voltage, then 1a and 2a will probably be zero, unless something is changing dynamically.

  

 I hope some of this makes sense, 

 Greg

  

 P.S. Is the old battery ground wire separate from the new ground wire?  If they are not connected to each other but still in place, try shorting the two together to see if the readings go back to normal. NOT + to - or VCC to ground for goodness sakes, unless you want to see a lot of sparks! Just connect new ground to the old ground, and the new vcc to the old vcc.  You might try this one first, since it is easier. If the old battery wires are taken out, then never mind.



   From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Karl Heindl

Sent: Thursday, July 29, 2010 2:28 PM

To: europa-list(at)matronics.com

Subject: RE: Voltage reading of 25V

 

Greg,

 

The problem is with the EIS, only why did it coincide with a battery move ?

 

I checked the voltage in the panel and everything looks fine with the main system. 

 

The EIS gives good readings with the engine off. Thde only anomaly is the voltage which says 11.0, when it should be 12.5.

When I start the engine the readings go haywire: oil temp is below of what is possible, pressure is 99, cht is 900C. After switching the EIS off and on a few times the readings are good. But then the numbers start bouncing around again. Of course Grand Rapids are closed for Oshkosh until Monday, and I am not sure what to do.

Any other ideas ?

 

Karl 

[quote] 



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[b]

g-iani(at)ntlworld.com
Guest

Posted: Fri Jul 30, 2010 12:26 am Post subject: Voltage reading of 25V

Karl  

   

I have the Grand Rapids and have had a similar problem with some very strange readings.  The symptoms were that half the readings produced by the unit were OK but the other half were all over the place.  

   

I contacted Grand Rapids and they were helpful but could not offer a particular explanation.  After a lot of investigation, including pulling out the entire unit, I found that all it was a broken cylinder head temp probe.  Once this was disconnected everything else went back to normal.  With the probe replaced everything was OK.  

   

So my recommendation is to disconnect the sensors one at a time until you find the duff one  

   

   

Ian Rickard G-IANI XS Trigear, 300hours

 Europa Club Mods Specialist

 e-mail g-iani(at)ntlworld.com   

        [quote][b]

kheindl(at)msn.com
Guest

Posted: Fri Jul 30, 2010 4:18 am Post subject: Voltage reading of 25V

Thanks Ian, I'll do that as well. I already removed the ch probe, because the wire was corroded, repaired the wire, but it didn't change anything.

 My strongest lead is the fact that this only happens when the engine is running.

  

 Karl

 



  

  From: g-iani(at)ntlworld.com

To: europa-list(at)matronics.com

Subject: RE: Voltage reading of 25V

Date: Fri, 30 Jul 2010 09:24:23 +0100



   .ExternalClass p.ecxMsoNormal, .ExternalClass li.ecxMsoNormal, .ExternalClass div.ecxMsoNormal {margin-bottom:.0001pt;font-size:12.0pt;font-family:'Times New Roman','serif';} .ExternalClass a:link, .ExternalClass span.ecxMsoHyperlink {color:blue;text-decoration:underline;} .ExternalClass a:visited, .ExternalClass span.ecxMsoHyperlinkFollowed {color:purple;text-decoration:underline;} .ExternalClass p {margin-right:0cm;margin-left:0cm;font-size:12.0pt;font-family:'Times New Roman','serif';} .ExternalClass pre {margin-bottom:.0001pt;font-size:10.0pt;font-family:'Courier New';} .ExternalClass span.ecxecx104564021-29072010 {;} .ExternalClass span.ecxHTMLPreformattedChar {font-family:Consolas;} .ExternalClass span.ecxEmailStyle21 {font-family:'Calibri','sans-serif';color:#1F497D;} .ExternalClass .ecxMsoChpDefault {font-size:10.0pt;} (at)page WordSection1 {size:612.0pt 792.0pt;} .ExternalClass div.ecxWordSection1 {page:WordSection1;}     

Karl 

  

I have the Grand Rapids and have had a similar problem with some very strange readings.  The symptoms were that half the readings produced by the unit were OK but the other half were all over the place. 

  

I contacted Grand Rapids and they were helpful but could not offer a particular explanation.  After a lot of investigation, including pulling out the entire unit, I found that all it was a broken cylinder head temp probe.  Once this was disconnected everything else went back to normal.  With the probe replaced everything was OK. 

  

So my recommendation is to disconnect the sensors one at a time until you find the duff one 

  

  

Ian Rickard G-IANI XS Trigear, 300hours

Europa Club Mods Specialist

e-mail g-iani(at)ntlworld.com 

[quote]



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