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FLYaDIVE(at)aol.com
Guest

Posted: Fri Sep 29, 2006 4:27 am Post subject: battery cables & Relays

Bob & Gaggle:



I took a look at the picture of the relay installation (see: 

http://aeroelectric.com/articles/Battery_Grounds/Battery_Grounds.html  )



 	  Quote: 	
		  From my experience I have found that the particular relay design being used 

has a failure point ESPECIALLY if installed in the position shown (Cap Side 
	


Down).

The failure point is the rolled over edge.  In the construction there is a 

rubber gasket between the cap and the can to keep the moisture out.  But what 

happens is moisture collects in the area between the can and cap lips, rust 

occurs and that weakens the bond and moisture seeps its way around and past the 

rubber gasket. The failure is internal rust on the solenoid slug (sticking) and 

rust on the steel contact brackets (breaking off or bending away from contact).



The two step CURE:



1 - Before installing the relay, seal that area.  I did mine by dipping the 

entire relay in EPOXY Paint.  Of course I masked off the terminals and any 

needed ground tap point. (Some relays use the case for Ground.  The ones in the 

picture are four terminal type and uses one coil terminal as Ground.  Others are 

three terminal type and use the case as Ground.



2 - Mount the relay so the Cap is facing UP.

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



We are learning things everyday, I hope.  And time is a great teacher.  

Unfortunately time is never recoverable and always long in happening.  Time taught 

me this problem and also this cure.

On the installation of the battery cables as described in the above web link, 

do the following:

Install Internal Star Washers between the Ground Point and the washer and 

another Internal Star Washer between the Cable Lug and the top washer.  Use a 

Conductive Grease, on the entire connection.

Why all this?  Because from my own experience and that of MANY auto shops 

Grounding to aluminum is a major conductive problem.  Corrosion occurs and MANY 

.. MANY electrical problems can be traced to nothing more than a corroded 

Ground connection.

 	  Quote: 	
		  From here on I'm just elaborating so you don't have to read it.

I recently had the following problems on a car:
	


Engine would over heat when idling.

Transmission would not shift.

Cruse Control would not work.

Battery would not charge.

Alternator would not put out the required voltage.



The CAUSE ... BAD GROUND on the ALUMINUM ENGINE BLOCK.

CURE ... What I mentioned above with the Internal Star Washer.



One connection ... All those problems.

Barry

"Chop'd Liver"



"Show them the first time, correct them the second time, kick them the third 

time." 

Yamashiada

N6030X(at)DaveMorris.com
Guest

Posted: Fri Sep 29, 2006 6:35 am Post subject: battery cables & Relays

Or maybe you could mount it at a slight angle so that any liquid will 

drain off, but you still maintain the resistance to having positive 

G-forces wanting to open the contacts, like this (look just below the battery):

http://www.davemorris.com/Photos/Mooney%20N6030X%20Guts%20-%20Firewall%20Fwd/IMG_1799.jpg

Dave Morris

At 07:26 AM 9/29/2006, you wrote:

 	  Quote: 	

Bob & Gaggle:

I took a look at the picture of the relay installation (see:

http://aeroelectric.com/articles/Battery_Grounds/Battery_Grounds.html  )

 >From my experience I have found that the particular relay design being used

has a failure point ESPECIALLY if installed in the position shown (Cap Side

Down).

The failure point is the rolled over edge.  In the construction there is a

rubber gasket between the cap and the can to keep the moisture out.  But what

happens is moisture collects in the area between the can and cap lips, rust

occurs and that weakens the bond and moisture seeps its way around 

and past the

rubber gasket. The failure is internal rust on the solenoid slug 

(sticking) and

rust on the steel contact brackets (breaking off or bending away 

from contact).

The two step CURE:

1 - Before installing the relay, seal that area.  I did mine by dipping the

entire relay in EPOXY Paint.  Of course I masked off the terminals and any

needed ground tap point. (Some relays use the case for Ground.  The 

ones in the

picture are four terminal type and uses one coil terminal as 

Ground.  Others are

three terminal type and use the case as Ground.

2 - Mount the relay so the Cap is facing UP.

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

We are learning things everyday, I hope.  And time is a great teacher.

Unfortunately time is never recoverable and always long in 

happening.  Time taught

me this problem and also this cure.

On the installation of the battery cables as described in the above web link,

do the following:

Install Internal Star Washers between the Ground Point and the washer and

another Internal Star Washer between the Cable Lug and the top washer.  Use a

Conductive Grease, on the entire connection.

Why all this?  Because from my own experience and that of MANY auto shops

Grounding to aluminum is a major conductive problem.  Corrosion 

occurs and MANY

... MANY electrical problems can be traced to nothing more than a corroded

Ground connection.

 >From here on I'm just elaborating so you don't have to read it.

I recently had the following problems on a car:

Engine would over heat when idling.

Transmission would not shift.

Cruse Control would not work.

Battery would not charge.

Alternator would not put out the required voltage.

The CAUSE ... BAD GROUND on the ALUMINUM ENGINE BLOCK.

CURE ... What I mentioned above with the Internal Star Washer.

One connection ... All those problems.

Barry

"Chop'd Liver"

"Show them the first time, correct them the second time, kick them the third

time."

Yamashiada

nuckollsr(at)cox.net
Guest

Posted: Fri Sep 29, 2006 9:36 am Post subject: battery cables & Relays

At 08:26 AM 9/29/2006 -0400, you wrote:



 	  Quote: 	
		  



Bob & Gaggle:



I took a look at the picture of the relay installation (see:

http://aeroelectric.com/articles/Battery_Grounds/Battery_Grounds.html )



 >From my experience I have found that the particular relay design being used

has a failure point ESPECIALLY if installed in the position shown (Cap Side

Down).

The failure point is the rolled over edge.  In the construction there is a

rubber gasket between the cap and the can to keep the moisture out.  But what

happens is moisture collects in the area between the can and cap lips, rust

occurs and that weakens the bond and moisture seeps its way around and 

past the

rubber gasket. The failure is internal rust on the solenoid slug 

(sticking) and

rust on the steel contact brackets (breaking off or bending away from 

contact).



The two step CURE:



1 - Before installing the relay, seal that area.  I did mine by dipping the

entire relay in EPOXY Paint.  Of course I masked off the terminals and any

needed ground tap point. (Some relays use the case for Ground.  The ones 

in the

picture are four terminal type and uses one coil terminal as 

Ground.  Others are

three terminal type and use the case as Ground.


	


   This style of contactor is not, as you have observed, suitable for

   situations where it's likely to be splashed or dripped on. Cessna

   went through the "lets seal it up" routine back in early 80s when

   the new floating cowl would allow rainwater to run down the front

   of the firewall. They tried several techniques to "seal" these devices

   with mixed success.



   In many cases, attempts to seal only make matters worse. Consider

   an airplane sitting out on the ramp on a warm sunny day. A little

   shower comes by and sprinkles the "sealed" relay with cool water.

   The pressure inside the container goes down due to cooling and

   water is sucked into the enclosure through the tiniest hole

   (ukum-gukies applied to outside are NOT hermetic seals).



   Now, moisture that came in as liquid through the tiny hole

   has to escape through the same hole as a vapor under the

   influence of atmospheric pressure changes. The end result

   for many of Cessna's efforts was that some folks experienced

   fewer failures due to moisture, but some had more.



   Some years prior to the Cessna experience, I was head

   techowiennie for an amateur radio repeater club. We had a

   much coveted location on the 1200 foot platform of KTVH

   channel 12 over in Hutchinson KS. See:



http://www.aeroelectric.com/Pictures/Misc/KTVH.gif



   We gathered up donations totaling about $4000 to buy

   a band new Motorola Micore repeater. Great radio, great

   location, longest legged repeater in Kansas.



   Every time it rained, the repeater went off the

   air and took some time to recover. We started a series

   of attempts to keep moisture out of the cabinet and

   the harder we tried, the longer it took to go off

   the air . . . and longer to recover.



   Finally discovered that the best bet was to leave the

   cabinet well vented to atmosphere and install internal

   circulation fans and heaters. Repeater still went off the

   air but recovered very quickly when the storm passed.



   In the case of our el-cheeso contactors, the first

   consideration is keep the water off. If that's not

   practical, mount cap-down and drill generous drain

   holes in cap (be careful when the drill punches

   through).



   Somebody mentioned contactor orientation preferences

   to offset aerodynamic g-loading on contactor in

   flight. There's a great deal of hangar-myth circulating

   around out there about contactor compromise due to

   g-loads . . . all wrong. If there's a mounting

   preference, it will be for the purposes of letting

   the water drain out. Attempts to "seal" are problematic

   and exceedingly difficult to test.



   These contactors have been used since the mid-40's

   on all manner of vehicle and been shown to be of

   good value . . . but they're NOT sealed and excessive

   local moisture is likely to cause problems.



   Bob . . .

nuckollsr(at)cox.net
Guest

Posted: Fri Sep 29, 2006 9:48 am Post subject: battery cables & Relays

At 08:26 AM 9/29/2006 -0400, you wrote:



 	  Quote: 	
		  



Bob & Gaggle:



I took a look at the picture of the relay installation (see:

http://aeroelectric.com/articles/Battery_Grounds/Battery_Grounds.html )



 >From my experience I have found that the particular relay design being used

has a failure point ESPECIALLY if installed in the position shown (Cap Side

Down).

The failure point is the rolled over edge.  In the construction there is a

rubber gasket between the cap and the can to keep the moisture out.  But what

happens is moisture collects in the area between the can and cap lips, rust

occurs and that weakens the bond and moisture seeps its way around and 

past the

rubber gasket. The failure is internal rust on the solenoid slug 

(sticking) and

rust on the steel contact brackets (breaking off or bending away from 

contact).



The two step CURE:



1 - Before installing the relay, seal that area.  I did mine by dipping the

entire relay in EPOXY Paint.  Of course I masked off the terminals and any

needed ground tap point. (Some relays use the case for Ground.  The ones 

in the

picture are four terminal type and uses one coil terminal as 

Ground.  Others are

three terminal type and use the case as Ground.


	


   This style of contactor is not, as you have observed, suitable for

   situations where it's likely to be splashed or dripped on. Cessna

   went through the "lets seal it up" routine back in early 80s when

   the new floating cowl would allow rainwater to run down the front

   of the firewall. They tried several techniques to "seal" these devices

   with mixed success.



   In many cases, attempts to seal only make matters worse. Consider

   an airplane sitting out on the ramp on a warm sunny day. A little

   shower comes by and sprinkles the "sealed" relay with cool water.

   The pressure inside the container goes down due to cooling and

   water is sucked into the enclosure through the tiniest hole

   (ukum-gukies applied to outside are NOT hermetic seals).



   Now, moisture that came in as liquid through the tiny hole

   has to escape through the same hole as a vapor under the

   influence of atmospheric pressure changes. The end result

   for many of Cessna's efforts was that some folks experienced

   fewer failures due to moisture, but some had more.



   Some years prior to the Cessna experience, I was head

   techowiennie for an amateur radio repeater club. We had a

   much coveted location on the 1200 foot platform of KTVH

   channel 12 over in Hutchinson KS. See:



http://www.aeroelectric.com/Pictures/Misc/KTVH.gif



   We gathered up donations totaling about $4000 to buy

   a band new Motorola Micore repeater. Great radio, great

   location, longest legged repeater in Kansas.



   Every time it rained, the repeater went off the

   air and took some time to recover. We started a series

   of attempts to keep moisture out of the cabinet and

   the harder we tried, the longer it took to go off

   the air . . . and longer to recover.



   Finally discovered that the best bet was to leave the

   cabinet well vented to atmosphere and install internal

   circulation fans and heaters. Repeater still went off the

   air but recovered very quickly when the storm passed.



   In the case of our el-cheeso contactors, the first

   consideration is keep the water off. If that's not

   practical, mount cap-down and drill generous drain

   holes in cap (be careful when the drill punches

   through).



   Somebody mentioned contactor orientation preferences

   to offset aerodynamic g-loading on contactor in

   flight. There's a great deal of hangar-myth circulating

   around out there about contactor compromise due to

   g-loads . . . all wrong. If there's a mounting

   preference, it will be for the purposes of letting

   the water drain out. Attempts to "seal" are problematic

   and exceedingly difficult to test.



   These contactors have been used since the mid-40's

   on all manner of vehicle and been shown to be of

   good value . . . but they're NOT sealed and excessive

   local moisture is likely to cause problems.



   Bob . . .

Jim Baker

Joined: 30 Mar 2006
Posts: 181
Location: Sayre, PA

Posted: Fri Sep 29, 2006 12:52 pm Post subject: battery cables & Relays

 	  Quote: 	
		     They tried several techniques to "seal" these devices

    with mixed success.

snip....
	




 	  Quote: 	
		      (ukum-gukies applied to outside are NOT hermetic seals).


	


Also known as encapsulation.



Which leads to the question...and perhaps overkill for this 

issue...would full-blown potting be a possibility here? Assuming 

no detrimental outgassing from the potting material, just make 

some pigtail leads from the unit and pot the wires and 

connectors as well. 



Geeq, I just love making the simple absurd.....



Jim Baker

580.788.2779

Elmore City, OK

nuckollsr(at)cox.net
Guest

Posted: Fri Sep 29, 2006 2:40 pm Post subject: battery cables & Relays

At 03:49 PM 9/29/2006 -0500, you wrote:

 	  Quote: 	

 >   They tried several techniques to "seal" these devices

 >    with mixed success.

snip....

 >    (ukum-gukies applied to outside are NOT hermetic seals).

Also known as encapsulation.

Which leads to the question...and perhaps overkill for this

issue...would full-blown potting be a possibility here? Assuming

no detrimental outgassing from the potting material, just make

some pigtail leads from the unit and pot the wires and

connectors as well.

Geeq, I just love making the simple absurd.....

   That's been done! Actually, the last time I saw

   that was on a piece of electronics that needed to

   run submerged to about 100' of water column. The

   tech found some thixotropic RTV and painted the

   assembly with several coats . . . with a vacuum

   pull on the last coat before it set up. The idea

   was that any opening allowing an outgas would bubble

   through and releasing the vacuum would suck RTV

   into the void.

   It looked like it ought to work. Makes 'em

   hard to repair!

   Bob . . .

FLYaDIVE(at)aol.com
Guest

Posted: Fri Sep 29, 2006 3:44 pm Post subject: battery cables & Relays

In a message dated 9/29/2006 4:57:52 PM Eastern Standard Time, jlbaker(at)msbit.net writes:

  	  Quote: 	
		  >   They tried several techniques to "seal" these devices

 	  Quote: 	
		      with mixed success.

snip....
	




 	  Quote: 	
		      (ukum-gukies applied to outside are NOT hermetic seals).


	


Also known as encapsulation.



Which leads to the question...and perhaps overkill for this 

issue...would full-blown potting be a possibility here? Assuming 

no detrimental outgassing from the potting material, just make 

some pigtail leads from the unit and pot the wires and 

connectors as well. 



Geeq, I just love making the simple absurd....



Jim Baker

580.788.2779

Elmore City, OK 	


 =========================================

 Jim:

  

 I am a very firm believer in the K. I. S. S. M. E. principle.  Sure potting is a possibility, but what kind of potting and will it adhere any closer or better to the unit than dipped epoxy paint?  I doubt it!  

 ONLY time will tell.

  

 I ... Let me repeat that ... I ... Not "They", I did the simple dipping of the relay in an epoxy paint over 9 years ago and have NOT had a single relay problem since.  I am doing the testing and Of course, as I said, only TIME will tell.  According to my log books the relay was replace once before.  That means I am on the third relay in 33 years.  Now, 33 divided 3 is a relay once every 11 years .... Well, ask me how it is doing in three more years.  That will equal the previous data, but I'm going for the record and beat that data.

  

 So, Jim, keep making the simple absurd ... It keep the gray matter stimulated.  Just don't believe the absurd.

  

 Barry

"Chop'd Liver"



"Show them the first time, correct them the second time, kick them the third time." 

Yamashiada

  [quote][b]

FLYaDIVE(at)aol.com
Guest

Posted: Sat Sep 30, 2006 2:35 am Post subject: battery cables & Relays

In a message dated 9/29/06 10:41:18 AM Eastern Daylight Time, 

N6030X(at)DaveMorris.com writes:



 	  Quote: 	
		   Or maybe you could mount it at a slight angle so that any liquid will 

  drain off, but you still maintain the resistance to having positive 

  G-forces wanting to open the contacts, like this (look just below the 

 battery):

  

http://www.davemorris.com/Photos/Mooney%20N6030X%20Guts%20-%20Firewall%20Fwd/
	


 	  Quote: 	
		   IMG_1799.jpg

  

  Dave Morris

==============================
	


Yes, Dave, the mounting in that picture is very poor and in an exposed area 

to many of the elements.  In that installation more than moisture ... Water ... 

Will collect.  Mounting it CAP UP will eliminate the pooling of water and a 

little dipping action as I described will take care of the rest.  



As for the 'G' forces, well that idea has been kicked around so much it is 

like a month old hair ball.  <--- I have no idea what that means.

But it is really not an issue.  Nothing we do in flying will approach a 'G' 

Force or duration that will pull the contacts apart. 

W E L L ... Maybe some of the landings I have seen   But there again 

during that moment I don't think the person is looking for a flickering of the 

radios ... Well, maybe they were and that is why the hard landing?

LoL



Barry

"Chop'd Liver"



"Show them the first time, correct them the second time, kick them the third 

time." 

Yamashiada

N6030X(at)DaveMorris.com
Guest

Posted: Sat Sep 30, 2006 5:49 am Post subject: battery cables & Relays

I thought the whole reason for mounting them upside down in the first 

place was the g-force issue.  Otherwise, it just looks wrong to mount 

it with the hat down!! LOL!

Dave

At 05:33 AM 9/30/2006, you wrote:

 	  Quote: 	

In a message dated 9/29/06 10:41:18 AM Eastern Daylight Time,

N6030X(at)DaveMorris.com writes:

 > Or maybe you could mount it at a slight angle so that any liquid will

 >  drain off, but you still maintain the resistance to having positive

 >  G-forces wanting to open the contacts, like this (look just below the

 > battery):

 >

http://www.davemorris.com/Photos/Mooney%20N6030X%20Guts%20-%20Firewall%20Fwd/

 > IMG_1799.jpg

 >

 >  Dave Morris

==============================

Yes, Dave, the mounting in that picture is very poor and in an exposed area

to many of the elements.  In that installation more than moisture 

... Water ...

Will collect.  Mounting it CAP UP will eliminate the pooling of water and a

little dipping action as I described will take care of the rest.

As for the 'G' forces, well that idea has been kicked around so much it is

like a month old hair ball.  <--- I have no idea what that means.

But it is really not an issue.  Nothing we do in flying will approach a 'G'

Force or duration that will pull the contacts apart.

W E L L ... Maybe some of the landings I have seen   But there again

during that moment I don't think the person is looking for a 

flickering of the

radios ... Well, maybe they were and that is why the hard landing?

LoL

Barry

"Chop'd Liver"

"Show them the first time, correct them the second time, kick them the third

time."

Yamashiada

Bob McC

Joined: 09 Jan 2006
Posts: 258
Location: Toronto, ON

Posted: Sat Sep 30, 2006 9:54 am Post subject: battery cables & Relays

Dave;



The "G" forces required to open a closed contactor are generally not

survivable. (or at least very close to it). I don't have quantitative

numbers, but I have tried pulling one open and the force required is VERY

significant. Many, many times that required to close it.



Bob McC

---

_________________
Bob McC
Falco #908
(just starting)

nuckollsr(at)cox.net
Guest

Posted: Sat Sep 30, 2006 2:16 pm Post subject: battery cables & Relays

At 01:51 PM 9/30/2006 -0400, you wrote:



 	  Quote: 	
		  

<robert.mccallum2(at)sympatico.ca>



Dave;



The "G" forces required to open a closed contactor are generally not

survivable. (or at least very close to it). I don't have quantitative

numbers, but I have tried pulling one open and the force required is VERY

significant. Many, many times that required to close it.



Bob McC


	


   Yes, the whole g-forces on contactors thing was bogus from

   the get-go.  I was at OSH one year when the story went around

   about some performer landing with a chewed up ring-gear. The

   "story" was that g-forces must have energized his starter

   contactor. Odds are that he was thinking really hard about the

   show ahead and took off with a stuck contactor.



   A study of the accelerations necessary to open a battery contactor

   or close a starter contactor just doesn't support the popular

   stories.

   Bob . . .



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

      < What is so wonderful about scientific truth...is that >

      < the authority which determines whether there can be   >

      < debate or not does not reside in some fraternity of   >

      < scientists; nor is it divine. The authority rests     >

      < with experiment.                                      >

      <                            --Lawrence M. Krauss       >

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

N6030X(at)DaveMorris.com
Guest

Posted: Sat Sep 30, 2006 3:17 pm Post subject: battery cables & Relays

So they why does everybody install them upside-down?  Has the myth taken hold?



Dave Morris



At 05:15 PM 9/30/2006, you wrote:

 	  Quote: 	
		  

<nuckollsr(at)cox.net>



At 01:51 PM 9/30/2006 -0400, you wrote:



>

><robert.mccallum2(at)sympatico.ca>

>

>Dave;

>

>The "G" forces required to open a closed contactor are generally not

>survivable. (or at least very close to it). I don't have quantitative

>numbers, but I have tried pulling one open and the force required is VERY

>significant. Many, many times that required to close it.

>

>Bob McC



   Yes, the whole g-forces on contactors thing was bogus from

   the get-go.  I was at OSH one year when the story went around

   about some performer landing with a chewed up ring-gear. The

   "story" was that g-forces must have energized his starter

   contactor. Odds are that he was thinking really hard about the

   show ahead and took off with a stuck contactor.



   A study of the accelerations necessary to open a battery contactor

   or close a starter contactor just doesn't support the popular

   stories.

   Bob . . .



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

      < What is so wonderful about scientific truth...is that >

      < the authority which determines whether there can be   >

      < debate or not does not reside in some fraternity of   >

      < scientists; nor is it divine. The authority rests     >

      < with experiment.                                      >

      <                            --Lawrence M. Krauss       >

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

nuckollsr(at)cox.net
Guest

Posted: Sat Sep 30, 2006 5:10 pm Post subject: battery cables & Relays

At 06:14 PM 9/30/2006 -0500, you wrote:



 	  Quote: 	
		  



So they why does everybody install them upside-down?  Has the myth taken hold?



Dave Morris


	


   Absolutely  . . . just like avionics master switches.



   Bob . . .

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