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Tyco Breakers

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cfi1513840

Joined: 11 Apr 2006
Posts: 14

Posted: Tue Jun 16, 2009 9:15 am Post subject: Tyco Breakers

Does anyone have any experience with the Tyco Rocker type switch/breaker?  

   

They are specified in the Digi-Key PTM as "secondary breakers", which must be backed up by a branch circuit breaker or fuse http://dkc1.digikey.com/us/en/tod/TycoElectronicsPB/CircuitBreakers_NoAudio/CircuitBreakers_NoAudio.html.  

   

This would seem to defeat the purpose of having the breaker in the first place. What am I missing?  

   

Ken Howell  

Glenwood, MD  

RV-7 Fuselage  

   

       [quote][b]

_________________
Ken Howell
Glenwood Maryland
RV-7 Wings

kuffel(at)cyberport.net
Guest

Posted: Tue Jun 16, 2009 2:47 pm Post subject: Tyco Breakers

Ken,



<< Does anyone have any experience with the Tyco Rocker type

switch/breaker?



I used the Tyco/Airpax/(now)Sensata/Snapak style rocker

circuit breaker/switches as primary power control in my

homebuilt in the mid-90s.  Gave excellent service, not one

failure.  I'm using the same style in the Sportsman I'm

currently building.  The specific type is

R11-1-[amperage]-G06EV.  They are Hydraulic-Magnetic type,

not thermal.  You can find all the specifications at

airpax.sensata.com.  Bob Nuckolls does not approve of this

arrangement.  But this type is specified as usable in

life-critical medical devices which, together with my

personal experience, is good enough for me.



Tom Kuffel, AL7AU

nuckolls.bob(at)aeroelect
Guest

Posted: Tue Jun 16, 2009 4:58 pm Post subject: Tyco Breakers

At 06:01 PM 6/16/2009, you wrote:

 	  Quote: 	
		  

<kuffel(at)cyberport.net>

Ken,



<< Does anyone have any experience with the Tyco Rocker type

switch/breaker?



I used the Tyco/Airpax/(now)Sensata/Snapak style rocker

circuit breaker/switches as primary power control in my

homebuilt in the mid-90s.  Gave excellent service, not one

failure.  I'm using the same style in the Sportsman I'm

currently building.  The specific type is

R11-1-[amperage]-G06EV.  They are Hydraulic-Magnetic type,

not thermal.  You can find all the specifications at

airpax.sensata.com.  Bob Nuckolls does not approve of this

arrangement.


	


   There's a BIG difference between approval and recommendation.

   I DON'T disapprove anything. I DO make recommendations based

   on cost of ownership and using parts in a manner that

   does put a mission at risk should a part fail.



 	  Quote: 	
		  But this type is specified as usable in

life-critical medical devices which, together with my

personal experience, is good enough for me.


	


   These are indeed Cadillac breaker/switches . . . with

   a price to match. But if your system design goals

   include achievement of failure tolerant design

   then the $extra$ cost only buys you a style

   of device and adds nothing to system reliability

   for the airplane.



   I've not seen this class of breaker used

   anywhere on a TC aircraft of any size or

   price.

        Bob . . .



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

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

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

nuckolls.bob(at)aeroelect
Guest

Posted: Tue Jun 16, 2009 5:13 pm Post subject: Tyco Breakers

At 12:08 PM 6/16/2009, you wrote:

  	  Quote: 	
		   Does anyone have any experience with the Tyco Rocker type switch/breaker?

  

 They are specified in the Digi-Key PTM as "secondary breakers", which must be backed up by a branch circuit breaker or fuse  http://dkc1.digikey.com/us/en/tod/TycoElectronicsPB/CircuitBreakers_NoAudio/CircuitBreakers_NoAudio.html .

  

 This would seem to defeat the purpose of having the breaker in the first place. What am I missing? 	


   Beats me. This is the first time I've seen that

   terminology used in describing the application

   of circuit protection. Did some searching and found

   this tid-bit . . .



 [img]cid:7.1.0.9.0.20090616200823.01e75d78(at)aeroelectric.com.0[/img] 



 

   This was excerpted from a book on wiring

   design for large AC power distribution systems.

   I don't think this applies to our 14/28V DC

   systems in light aircraft.



 

        Bob . . .



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

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

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

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cfi1513840

Joined: 11 Apr 2006
Posts: 14

Posted: Wed Jun 17, 2009 4:13 am Post subject: Tyco Breakers

It appears that they are referring to the primary and secondary windings of the transformer, and not in the sense of a “backup”.   

   

In a nutshell, here’s the way I interpret the Tyco spec: You can use our circuit breakers to protect a circuit, but you must also use another circuit breaker or fuse to protect the same circuit. Does that make sense?  

   

Ken  

   

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_________________
Ken Howell
Glenwood Maryland
RV-7 Wings

nuckolls.bob(at)aeroelect
Guest

Posted: Wed Jun 17, 2009 5:23 am Post subject: Tyco Breakers

At 07:11 AM 6/17/2009, you wrote:

  	  Quote: 	
		   It appears that they are referring to the primary and secondary windings of the transformer, and not in the sense of a “backup”. 

  

 In a nutshell, here’s the way I interpret the Tyco spec: You can use our circuit breakers to protect a circuit, but you must also use another circuit breaker or fuse to protect the same circuit. Does that make sense? 	


    Not in a small footprint DC power distribution

    system typical of a vehicle. You can use these

    breakers like any other breaker in crafting

    your project. The primary/secondary thing is

    unique to AC systems where transformers are

    used for changing voltage levels or offering

    isolation between sides of a system. Clearly

    we don't do this in little airplanes.



 

 

        Bob . . .



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

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

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



     [quote][b]

longg(at)pjm.com
Guest

Posted: Wed Jun 17, 2009 12:12 pm Post subject: Tyco Breakers

Ken,  

   

My street interpretation would be if I have to pay $20.00 for a  spotter/tyco switch breaker which isn’t really a breaker (it just says so) and $20.00 for tyco pull breaker, guess which one I would buy?  

   

J Glenn  

   

Do Not Archive  

       

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

 Sent: Wednesday, June 17, 2009 8:11 AM

 To: aeroelectric-list(at)matronics.com

 Subject: RE: Tyco Breakers  

  

  

   

It appears that they are referring to the primary and secondary windings of the transformer, and not in the sense of a “backup”.   

   

In a nutshell, here’s the way I interpret the Tyco spec: You can use our circuit breakers to protect a circuit, but you must also use another circuit breaker or fuse to protect the same circuit. Does that make sense?  

   

Ken  

   

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kuffel(at)cyberport.net
Guest

Posted: Thu Jun 18, 2009 3:58 am Post subject: Tyco Breakers

Question was:

 

<< experience with the Tyco Rocker type switch/breaker? >>

 

I replied:

 

<< I used the Tyco/Airpax/(now)Sensata/Snapak style rocker

circuit breaker/switches R11-1-[amperage]-G06EV. ..

airpax.sensata.com. Bob Nuckolls does not approve of this

arrangement. >>

 

Bob Nuckolls replied:

 

<<There's a BIG difference between approval and

recommendation.

I DON'T disapprove anything.>>

 

Felt Bob would take umbrage at the phrase the moment I

pressed the send button.  Okay, replace "does not approve

of" with "discourages use of".  Semantics anywhere but in a

government bureaucracy.

 

<< These are indeed Cadillac breaker/switches . . . with

a price to match. >>

 

Just went and looked.  Airpax style R11-1-[amp] are

available under $15.  This is half the AS&S price of the

Tyco thermal circuit breakers used in type certified

aircraft.

 

<< But if your system design goals

include achievement of failure tolerant design

then the $extra$ cost only buys you a style

of device and adds nothing to system reliability

for the airplane.>>

 

Here, Bob and I have disagreed before.  To me, the probable

reliability of this life rated switch/circuit breaker and

two connections is not automatically worse than the switch, 

wire across the panel to a circuit breaker array and 4

connections setup typical of most aircraft.  As I said, my

experience has been good, I'm confident in the reliability

of the device, I like the simplified wiring and also like

the reduced panel usage.

 

<< I've not seen this class of breaker used

anywhere on a TC aircraft of any size or

price. >>

 

Which is one of the reasons we build experimental aircraft,

so we can use stuff the TC world doesn't.

 

Tom Kuffel

cfi1513840

Joined: 11 Apr 2006
Posts: 14

Posted: Thu Jun 18, 2009 6:20 am Post subject: Tyco Breakers

Another interesting point in the Tyco literature is that they state that they don’t make “primary” breakers, meaning all Tyco breakers are “secondary” whether they are switch or pull-type, and must be backed up by another breaker or fuse in the branch circuit. I might check with Tyco to see if they can elaborate on this point, and if I learn anything useful, I’ll post it.  

   

My instinct tells me that the Tyco breakers would do the job for our application, but everything nowadays comes with some sort of caveat, probably included by the company lawyers.  

   

Ken  

   

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Ken Howell
Glenwood Maryland
RV-7 Wings

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Jun 18, 2009 7:02 pm Post subject: Tyco Breakers

 	  Quote: 	
		   

 Felt Bob would take umbrage at the phrase the moment I

 pressed the send button.  Okay, replace "does not approve

 of" with "discourages use of".  Semantics anywhere but in a

 government bureaucracy. 	


   You put words in my mouth still . . . my offering

   of simple ideas for the use of switch breakers

   pointed out that fact that switch breakers force

   the builder to fabricate a distribution bus on

   the panel . . . not unlike the breaker panels typical

   of TC aircraft even today.



   If one is favorably impressed with fuse blocks,

   then the fabrication of bus bars is already 

   accomplished with a purchased part . . . and

   can be mounted remotely from the panel. If one

   has fuse blocks, then the only panel real

   estate devoted to control/protection are the

   necessary switches. All protected circuits

   not requiring switches require no panel space.



   If one chooses to use a combination of switch/breakers

   and circuit/breakers, then the real estate budget

   is affected. I prefer and RECOMMEND the low real

   estate, low labor, low cost approach but I would

   not discourage anyone from wiring their airplane

   any way they wish that does not introduce hazardous

   failure modes. Certainly choices of breakers, switch-

   breakers and/or fuses do not offer great risks.

  	  Quote: 	
		   

 << These are indeed Cadillac breaker/switches . . . with

 a price to match. >>

  

 Just went and looked.  Airpax style R11-1-[amp] are

 available under $15.  This is half the AS&S price of the

 Tyco thermal circuit breakers used in type certified

 aircraft. 	


   The breakers in common to TC aircraft are mil-spec

   devices with price tags commensurate with

   their pedigree. There are other commercial/

   industrial breakers to be had for less money . . .

   the Airpax line you cited is but one.



  	  Quote: 	
		    < But if your system design goals

 include achievement of failure tolerant design

 then the $extra$ cost only buys you a style

 of device and adds nothing to system reliability

 for the airplane.>>

  

 Here, Bob and I have disagreed before.  To me, the probable

 reliability of this life rated switch/circuit breaker and

 two connections is not automatically worse than the switch, 

 wire across the panel to a circuit breaker array and 4

 connections setup typical of most aircraft. 	


   Breakers that assuage concerns for aircraft designers

   have terminal bosses compatible with bus bars that

   tie multiple devices together. Like . . .



 [img]cid:.0[/img]



 

   The R11 has fast-on tabs that do not lend themselves

   to direct connection to bus bars.



 [img]cid:.0[/img]



 



 

  	  Quote: 	
		    As I said, my

 experience has been good, I'm confident in the reliability

 of the device, I like the simplified wiring and also like

 the reduced panel usage. 	


    As to absolute reliability, the numbers are

    inversely proportional to parts count and without

    a doubt, the breaker/switch is more complex than

    the plain switch. Reliability is inarguable.



    Bonanza and Baron owners are presently saddled

    with some parts-count issues in the utilization

    of this breaker/switch . . .

 [img]cid:.1[/img]



    It's a sure bet that they're wishing we'd not

    strayed from the simple breaker-panel, switch-

    panel architecture common to most other airplanes.

    This albatross involves about 80,000 fielded

    breaker/switches.



    But had you chosen fuse blocks and rocker

    switches with fast-on tabs, you would be no

    greater parts count than using toggle switches

    with fast-on tabs. Further, you would not have

    to wrestle with the bus-bar connection issues

    presented by fast-on tabs.



  	  Quote: 	
		   

 << I've not seen this class of breaker used

 anywhere on a TC aircraft of any size or

 price. >>

  

 Which is one of the reasons we build experimental aircraft,

 so we can use stuff the TC world doesn't. 	




    Absolutely! An if you're pleased with the outcome

    of your choices, I'm pleased for you. But kindly

    refrain from mis-representing my mission here on the List.

    When I offer a particular recipe for success, it's

    supported by an analysis of design goals that

    I'm willing to share and explain. There are certainly

    other recipes that have met the builder's design goals . . .

    yours included.



    Bob . . .

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kuffel(at)cyberport.net
Guest

Posted: Fri Jun 19, 2009 9:47 pm Post subject: Tyco Breakers

Bob Nuckolls said:



<< switch breakers force

  the builder to fabricate a distribution bus on

  the panel . . . not unlike the breaker panels typical

  of TC aircraft even today. >>



<< Breakers that assuage concerns for aircraft designers

  have terminal bosses compatible with bus bars that

  tie multiple devices together. >>



Which is exactly what I did with my previous amateur built

aircraft using these breakers, connected all the breakers

together with one buss bar connected directly to the

terminals.

 

<< If one is favorably impressed with fuse blocks, >>



But I am not, which is the source of our differing approach.

 My friend, the rich man's chief pilot, has just spent a

large part of the last seven years fighting with the maker

of their new model $47 million private jet over the fact

they wanted to make all the fuses totally inaccessible in

flight.  Manufacturer lost the argument.  Same principle

applies to single pilot small aircraft with the automobile

style fuse block.



All I'm saying is if you are among those of us who are

uncomfortable without access to our circuit protection

devices, the Snapak magnetic-hydraulic R11-1 style circuit

breaker/switch rated for use in life critical medical

devices (albeit not mil-spec) is a viable, lower cost,

simpler and possibly more reliable alternative to the TC

common practice of acres of breakers way over there and

switches way over here.



Tom Kuffel

nuckolls.bob(at)aeroelect
Guest

Posted: Fri Jun 19, 2009 10:13 pm Post subject: Tyco Breakers

 	  Quote: 	
		  All I'm saying is if you are among those of us who are

uncomfortable without access to our circuit protection

devices, the Snapak magnetic-hydraulic R11-1 style circuit

breaker/switch rated for use in life critical medical

devices (albeit not mil-spec) is a viable, lower cost,

simpler and possibly more reliable alternative to the TC

common practice of acres of breakers way over there and

switches way over here.


	


    To each his own. Fly comfortably sir!

        Bob . . .



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

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

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

dhammer

Joined: 08 Apr 2009
Posts: 1
Location: Consultant

Posted: Sat Jun 20, 2009 11:13 am Post subject: Re: Tyco Breakers

[quote]

But I am not, which is the source of our differing approach.

 My friend, the rich man's chief pilot, has just spent a

large part of the last seven years fighting with the maker

of their new model $47 million private jet over the fact

they wanted to make all the fuses totally inaccessible in

flight.  Manufacturer lost the argument.  Same principle

applies to single pilot small aircraft with the automobile

style fuse block.



Tom Kuffel[/quote]

Tom,



I spend my life with private Jets.  I've never seen fuses in the cockpit, only circuit breakers.  Any fuses or current limiters in transport category aircraft, and there are hundreds, are always located where the crew can't touch them, along with many of the breakers they don't want the pilot to have access to.  You just don't want some stupid pilot starting a fire playing with them.  The rule that has always been pounded into my head is to accept the loss and fly the plane, not try and fix it.  That's how L-1011's end up in the swamp while pilots are trying to change gear indicator bulbs. 



The only aircraft I'm aware of that has few, but not no, breakers in the cockpit is Bombardier's Global Express.  It does, however, have remote breakers controlled by screens in the cockpit.  It saves a huge amount of weight running wires all the way from the hell hole to the cockpit and back.  Also the usability for the crew goes way up.  They can see all systems effected when a breaker is popped and can isolate a bus at will.  Also, if one pops you get a message.



That being said, no manufacturer is going to change his Type Certificated product based on the whims of some ego-centric pilot.  Funny, but the buyer of that $47M aircraft is sitting in the back.  That's the ones the manufacturer's listen to and not the hired hands up front. Trust me on that one.



Cockpits and panel layout of all new aircraft are now part of the certificate and short of adding a third something cannot be altered without a big STC project.  I'd be interested in knowing what aircraft model you are talking about.



Cheers,



Don

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Jun 21, 2009 10:09 am Post subject: Tyco Breakers

At 02:13 PM 6/20/2009, you wrote:

 	  Quote: 	
		  



 	  Quote: 	
		  

But I am not, which is the source of our differing approach.

  My friend, the rich man's chief pilot, has just spent a

large part of the last seven years fighting with the maker

of their new model $47 million private jet over the fact

they wanted to make all the fuses totally inaccessible in

flight.  Manufacturer lost the argument.  Same principle

applies to single pilot small aircraft with the automobile

style fuse block.



Tom Kuffel 	


Tom,



I spend my life with private Jets.  I've never seen fuses in the 

cockpit, only circuit breakers.  Any fuses or current limiters in 

transport category aircraft, and there are hundreds, are always 

located where the crew can't touch them, along with many of the 

breakers they don't want the pilot to have access to.  You just 

don't want some stupid pilot starting a fire playing with them.  The 

rule that has always been pounded into my head is to accept the loss 

and fly the plane, not try and fix it.  That's how L-1011's end up 

in the swamp while pilots are trying to change gear indicator bulbs.


	


   Exactly.  It's with this design goal in mind that

   we strive for failure tolerant design. I.e., loss

   of any single system should not put a mission at

   risk for bent airplanes -OR- people. Better yet,

   very low risk for even breaking a sweat.



   To be sure, there are things we cannot make failure

   tolerant. Wing struts, prop bolts, connecting rods,

   etc. At the same time, we design those components with

   some notion of robustness under normal use. Somehow,

   it's easy to allow certain electro-whizzies to

   take up residence in our "can't survive without it"

   basket of thought. Hence, we worry about them a lot

   and tend to get wrapped around a "push-the-breaker-

   and-HOPE-it-will-stay on" mentality. But as I pointed

   out some 15 years ago . . .



http://www.aeroelectric.com/articles/fuseorcb.html



   and elaborated upon it further 4 years later . . .



http://www.aeroelectric.com/articles/fusvbkr2.html



    . . . there are MANY ways an electro-whizzy can

   wander into the weeds WITHOUT opening it's supply

   circuit protection. Considering this inarguable fact,

   it seems prudent to design one's electrical system

   such that every device truly necessary for comfortable

   termination of flight have an independent backup

   . . . a Plan-B.



   Once the design goal is achieved, then it matters

   not what form the circuit protection takes nor

   does it matter where that protection is located.

   If one has plenty of panel space, low expectations

   for overall electrical system reliability (day vfr,

   fair weather flying) then covering the panel with

   acres-of-breakers-and-switches may be satisfying

   as a style statement . . . but adds nothing to

   system reliability while adding burden to empty weight,

   cockpit complexity, time to install and cost of

   ownership.



The only aircraft I'm aware of that has few, but not no, breakers in 

the cockpit is Bombardier's Global Express.  It does, however, have 

remote breakers controlled by screens in the cockpit.  It saves a 

huge amount of weight running wires all the way from the hell hole to 

the cockpit and back.  Also the usability for the crew goes way 

up.  They can see all systems effected when a breaker is popped and 

can isolate a bus at will.  Also, if one pops you get a message.



   Yeah, I think Eclipse did this too.



   Bob . . .

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