# [EVDL] Fwd: 3 pole circuit breaker



## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

You have yet to explain why it wouldn't work?



> Travis Gintz <[email protected]> wrote:
> > Go for it, but It won't bring the voltage rating to 375V. Reread my
> > email from a PE, he reviewed this with two other EE's. Its come up
> > before with customers trying to shortcut and cut costs. The contacts
> ...


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## EVDL List (Jul 27, 2007)

Peter, thank you for your comment.... I see you're have not "borught
anything to the table" so I'll ignore what you said.

I actually just called Airpax applications. He said you CANNOT gang
them together as he wants to do. They are NOT designed for that
rating. They said they can design them to be used for 375 AT THE
FACTORY, but they are not rated. for that voltage. Its a safety issue.
It has to do about how the magnetic breaker works. Its not designed to
work at a higher voltage.

I don't HAVE to explain the physics principals of how it doesn't work.
Its not that it won't work, Its that it won't work as its supposed to.
You might get false trip (not too bad). But you may also get a long
trip, and that has the potential to cause an arc, and burn out the
controller/motor. Also when it does break the circuit, its a potential
safety issue. This discussion was never the how's and whys of it
working, but rather if he should do it.

Don't believe me. I've got a degree, and so do the 5 people i've gone
out of my way to talk to. At first because I wanted a second opinion.
I did this because I don't think its safe, nor is it advised by anyone
other than a few people online. I don't want to prove you wrong. I
don't want your car having a fire under the hood because you decided
to throw it together and wait until it DOESN'T work.

And why should I prove why it shouldn't work....no one has yet
explained to me why it CAN WORK! and how it IS SAFE? How about that?
I've proved more than enough, asked engineers and gotten AIRPAX to
back me.

I'm only asking that you reconsider, Call Airpax and ask their
applications engineer. I talked to George Evans at 410-221-9432. Ask
him why it won't work or why you shouldn't do it.

regards,
Travis

On 11/2/07, Peter Gabrielsson <[email protected]> wrote:
> You have yet to explain why it wouldn't work?
>
>


> Travis Gintz <[email protected]> wrote:
> > > Go for it, but It won't bring the voltage rating to 375V. Reread my
> > > email from a PE, he reviewed this with two other EE's. Its come up
> > > before with customers trying to shortcut and cut costs. The contacts
> ...


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## EVDL List (Jul 27, 2007)

> Travis Gintz wrote:
> 
> > I forwarded this to my PE (professional engineer) buddy, who
> > specializes in High voltage and Power. This was his reply.
> ...


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## EVDL List (Jul 27, 2007)

Travis,
Thanks for trying to help, but you seem to be misunderstanding me a bit.

For one I was never trying to increase current rating, only voltage rating.

Second, this is incorrect "Why ask for advice if you aren'g going to
follow it?" because I decided not to use a 3-pole breaker after
finding out it wouldn't work.

I decided to use 3 single pole breakers on the suggestion of another EVer.
Your question to your friend was concerning the 3-pole breaker.
Which I believe is a different situation and so has nothing to do with
not taking advice.

Also this is the only place I have asked this question... (I asked a
similar but not the same question on the Alaska EV group)

Since Travis is bringing up these concerns and for safety sake can
anyone else comment on using 3 of these in series:

Airpax Part Number JLM-1-1RLS5 30140-250
125 Volt DC Circuit Breaker
Trip Amps 313
Hold Amps 250
Delay 53 Amps

...by the way I am also fusing the pack and everything is sealed and
there is going to be no exposed high voltage wiring so the main reason
for the breakers is for an extra means of protection and for use as an
on/off switch for working on the battery pack.

Cheers,
-- 
Tehben
'90 Toyota 4x4 Pickup
'hElix EV'
Website: www.helixev.com
evalbum: http://www.austinev.org/evalbum/1225

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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

> Thanks for trying to help, but you seem to be misunderstanding me a bit.
> For one I was never trying to increase current rating, only voltage rating.

I misread it at first about the current rating. I took that back and
researched for you further once I reread it. I responded after and
said I would contact someone about this issue.


> Second, this is incorrect "Why ask for advice if you aren'g going to
> follow it?" because I decided not to use a 3-pole breaker after
> finding out it wouldn't work.

But the theory is still the same, you're putting them in series. That
is what you asked. That is your application. Also, its against the
manufacturers recomended spec. Read the spec sheet. Call them.


> I decided to use 3 single pole breakers on the suggestion of another EVer.
> Your question to your friend was concerning the 3-pole breaker.
> Which I believe is a different situation and so has nothing to do with
> not taking advice.

How is it different? How can you know that the other ev'er was
correct? I'd follow the specs from the maker of the breaker you
bought... not what other people have done with theirs.

> Also this is the only place I have asked this question... (I asked a
> similar but not the same question on the Alaska EV group)

True, but it led into this question, and you obviously took their advice.


> Since Travis is bringing up these concerns and for safety sake can
> anyone else comment on using 3 of these in series:
>
> Airpax Part Number JLM-1-1RLS5 30140-250
> 125 Volt DC Circuit Breaker
> Trip Amps 313
> Hold Amps 250
> Delay 53 Amps

Can someone out there PROVE that its 100% safe? Can anyone prove that
the concerns I brought up are wrong? Are there other people doing this
out there?

> ...by the way I am also fusing the pack and everything is sealed and
> there is going to be no exposed high voltage wiring so the main reason
> for the breakers is for an extra means of protection and for use as an
> on/off switch for working on the battery pack.
>

If you use those breakers, then enclosing is the safest bet. Put the
box away from batteries, or anything that would ignite with a spark. I
think i read that these have arc paths in them. Put some extra metal
down, so if it arcs, and creates plasma, it doesn't get a chance to
melt through the enclosure before its extinguished.

I don't want to be all high and mighty, I just don't want someone to
get hurt using the wrong part, thats all. I work as an engineer with
customers that want to circumvent our specifications. While it may
work in some cases, it might not work in another. Thats not 100%.
Please don't take it as me being an asshole. All it takes is one screw
sheering off to cause a helicopter to spin out of control. All it
takes is one part in the system to cause a fire in an EV. Just be
careful. Call them, then test it out first.


-- 
Travis Gintz
1986 Honda VFR AC conversion
Http://blog.evfr.net/

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## EVDL List (Jul 27, 2007)

> Tehben Dean wrote:
> 
> > Since Travis is bringing up these concerns and for safety
> > sake can anyone else comment on using 3 of these in series:
> ...


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## EVDL List (Jul 27, 2007)

"It is very likely that using 3 single pole breakers in series like
this will be just fine"

Thats correct. But....I called them and they said not to. Call them
back if you don't believe me. You have yet to PROVE that its safe to
do.

Good luck Dean.

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## EVDL List (Jul 27, 2007)

> Travis Gintz wrote:
> 
> > I know about some manufacturers allowing it. But I called
> > Airpax, and they do not recommend it. Period. The engineer I
> ...


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## EVDL List (Jul 27, 2007)

> > I know about some manufacturers allowing it. But I called
> > Airpax, and they do not recommend it. Period. The engineer I
> > talked with was not confused.
>
> My response was to your high voltage high power specialist PE friend's remarks, not those or the Airpax engineer you later contacted.

That is who I was referring to in the above statement, the PE friends.
I'm sorry that was unclear, I'm writing a little bit at a time while
doing some autocad.


> > I forwarded him the quoted
> > question. Said that its DC, low voltage. He said that it can
> > be allowed with contactors, but is not a clear cut CORRECT
> > way to wire with breakers.
>
> And he may be correct that it is not a "correct" way to use his particular model of breaker, but it is incorrect to make a blanket statement of it being an incorrect way to use ANY breaker. The Square D bulletin I referred you to specifically describes connecting two single-pole breakers in series to achieve 2x the voltage rating of a single breaker, as well as describing the proper series connection of the poles of a single multiple pole breaker to achieve a higher voltage rating.

It wasn't making a blanked statement, I was saying unless its in the
spec, and the company recommends it, its not going to be 100%. it may
work, it may do what you need, but its not reliable, its not proven
safe. That statement is a 100% true statement, always. I'm saying "its
not ok to do, UNLESS..." Also, he's not using squareD. He's using
Airpax. Different manufacturers use different designs due to patent
laws. Do you know why airpax said No?

> While I appreciate the effort you've gone through in trying to get a definitive answer from Airpax for Tehben, we don't actually know what question you asked, and so there is a small possibility that the engineer correctly answered the wrong question, or was not provided a detail that might have tempered his response. For instance, that the breakers would be mechanically linked to force all poles to open and close together.

I said that I ordered some breakers, gave him the part number, and
told him that I needed to use these in a DC application where the
voltage was over 300V, but at the same current rating of the single
breaker. I then asked if I could put them in series to acheive the
voltage rating I need, with the handles tied together. He laughed and
said no, and that If I needed something rated for that, they could do
it at the factory where they make custom breakers. He did not
elaborate other than it was to do with the design of the magnetic part
of the breaker, and how it actually breaks contact.

> > If the manufacturer does not recomend it, and its operated
> > outside of spec, is it safe? Well, we don't know. But its not
> > 100% now is it?
>
> Exactly! ;^> Just because the manufacturer won't go on record as recommending something doesn't mean it won't work (liability and all that), and often the voltage ratings are simply the level to which the device was tested, not the level at which it fails. (Standard ratings seem to be 63V, 125V, 160V, 250V, 500V, etc., so a device rated 125V might actually work up to almost 160V or even almost 250V, but simply wasn't tested for anything but the 125V rating (testing costs).

I said its not SAFE and he shouldn't do it without reading the spec,
and calling the manufacturer. It could work, but for how long? and
what if there is a problem? Who's liable? Who gets hurt? whats the
damage? And as far as ratings, they always push the device to the
failure limit... and derate it according to their procedures. GE
Energy derated all of their stuff 25-50%. It would operate at a higher
voltage/current, but the life was decreased and failures increased
over time.


> If Tehben wants to use something outside of its intended applicaiton/ratings, then he may have to test it himself to verify that it does work acceptably for him.

Yup. Just hope he's careful, thats all i was trying to say.

If I could stop one person, who may not know the dangers of something,
whether it be a kid running into a street, or an electrician wiring up
600VDC on a bus.... I'm 100% going to warn them 100% of the time. Its
not is it righ or wrong, or will it work, its the REMOTE POSSIBILITY
that something could go wrong.

Thanks, Its been a fun day at work, talking to people in the other
engineering department. I haven't met some of them yet, so if
anything, I met some new people today!

-- 
Travis Gintz
1986 Honda VFR AC conversion
Http://blog.evfr.net/

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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

Gee, you did a really poor job ignoring me there. Perhaps the way I
stated my question could have been better,but, I was just wondering
why it wouldn't work?




> Travis Gintz <[email protected]> wrote:
> > Peter, thank you for your comment.... I see you're have not "borught
> > anything to the table" so I'll ignore what you said.
> >
> ...


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## EVDL List (Jul 27, 2007)

travis these guys are want to bes who already know it all with no experence in the electrical field and electronics training so they already know everything !!! I tried to warn a fellow on this subject about 6 mo ago and got blasted off the list for 3 mo . so tewll them once and then let them learn with their wallet
----- Original Message ----- 
From: Travis Gintz<mailto:[email protected]> 
To: Electric Vehicle Discussion List<mailto:[email protected]> 
Sent: Friday, November 02, 2007 2:18 PM
Subject: Re: [EVDL] Fwd: 3 pole circuit breaker


Peter, thank you for your comment.... I see you're have not "borught
anything to the table" so I'll ignore what you said.

I actually just called Airpax applications. He said you CANNOT gang
them together as he wants to do. They are NOT designed for that
rating. They said they can design them to be used for 375 AT THE
FACTORY, but they are not rated. for that voltage. Its a safety issue.
It has to do about how the magnetic breaker works. Its not designed to
work at a higher voltage.

I don't HAVE to explain the physics principals of how it doesn't work.
Its not that it won't work, Its that it won't work as its supposed to.
You might get false trip (not too bad). But you may also get a long
trip, and that has the potential to cause an arc, and burn out the
controller/motor. Also when it does break the circuit, its a potential
safety issue. This discussion was never the how's and whys of it
working, but rather if he should do it.

Don't believe me. I've got a degree, and so do the 5 people i've gone
out of my way to talk to. At first because I wanted a second opinion.
I did this because I don't think its safe, nor is it advised by anyone
other than a few people online. I don't want to prove you wrong. I
don't want your car having a fire under the hood because you decided
to throw it together and wait until it DOESN'T work.

And why should I prove why it shouldn't work....no one has yet
explained to me why it CAN WORK! and how it IS SAFE? How about that?
I've proved more than enough, asked engineers and gotten AIRPAX to
back me.

I'm only asking that you reconsider, Call Airpax and ask their
applications engineer. I talked to George Evans at 410-221-9432. Ask
him why it won't work or why you shouldn't do it.

regards,
Travis

On 11/2/07, Peter Gabrielsson <[email protected]<mailto[email protected]>> wrote:
> You have yet to explain why it wouldn't work?
>
>


> Travis Gintz <[email protected]<mailto:[email protected]>> wrote:
> > > Go for it, but It won't bring the voltage rating to 375V. Reread my
> > > email from a PE, he reviewed this with two other EE's. Its come up
> > > before with customers trying to shortcut and cut costs. The contacts
> ...


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## EVDL List (Jul 27, 2007)

BECAUSE WHEN THE BREAKER OPENS UNDER LOAD THE VOLTAGE WILL BE HIGH ENOUGH WITH THE AVAILABLE CURRENT TO ARC FLASH ACROSS THE CONTACTS AND EITHER WELD THEM CLOSED OR TURN THE CONTACTS AND BREAKER IN PLASMA oops just found the caps lock on did not shout just goofed
----- Original Message ----- 
From: Peter Gabrielsson<mailto[email protected]> 
To: Electric Vehicle Discussion List<mailto:[email protected]> 
Sent: Friday, November 02, 2007 7:13 PM
Subject: Re: [EVDL] Fwd: 3 pole circuit breaker


Gee, you did a really poor job ignoring me there. Perhaps the way I
stated my question could have been better,but, I was just wondering
why it wouldn't work?




> Travis Gintz <[email protected]<mailto:[email protected]>> wrote:
> > Peter, thank you for your comment.... I see you're have not "borught
> > anything to the table" so I'll ignore what you said.
> >
> ...


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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

I have a hard copy of a Merlin Gerin (same family as SquareD) breaker
catalogue which I knew had a page towards the back about using multi-pole
MCBs in DC applications...

This appears to be the PDF (but I'm on a slow dial-up connection right now
and it's 1am and I'm off to bed, so can't double-check...)

http://www.schneider-electric.co.uk/internet/pws/literature.nsf/luAllByID/JP
AE-58GKVQ/$file/Merlin_Gerin_Circuit_breaker_application_guide_full_MGD5032.
pdf

Hope this helps!

Matt

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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

Thanks for the level headed explanation Morgan. It would seem though
that several breaker manufacturers have successfully engineered their
breakers to open close enough to simultaneous that this is not an
issue. I guess it just depends on what specific breaker you're using.





> Morgan LaMoore <[email protected]> wrote:
> > On 11/2/07, Peter Gabrielsson <[email protected]> wrote:
> > > You have yet to explain why it wouldn't work?
> > >
> ...


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## EVDL List (Jul 27, 2007)

Wow nice thread. I've been out of town for 3 days or I'd have commented sooner. While I agree with Brian Gilbert about Tehben's
first choice of the 3 pole Square D breaker being the preferred alternative the multiple Airpax breakers that I am using in this
fashion are an acceptable compromise for me. As was stated before the "Engineered" breakers meant to trip together within a tight
tolerance and are specified by their manufacturer to be run in series to increase the voltage rating of the assembly would always
be my preferred alternative. I would also insist as others have, that the individual Airpax breakers not be used in this fashion
IF they were depended on for emergency disconnects. In my case however the individual series breakers are really only intended to
be used as my manual disconnect switch. While the breakers will still exhibit high voltage and high current breaking
capabilities, the primary and secondary safety devices are the main contactor coltrol from the Zilla (as well as my manual main
contactor coil disconnect on the dash) and the inline 500A fuse in the battery pack. Granted the breakers will attemp to trip
before the fuse (and they have during high power testing). Although the ganged handles on the breakers may be unreliable at
ensuring the contacts open at exactly the same time, and although this may cause one of the contacts (or even both) to become
welded, the primary and secondary safety disconnects are still in place. And replacing the welded breakers is no big deal because
these Airpax breakers are inexpensive. Of course a PE will always tell you to go by the book because they are sworn to protect
public safety, and a manufacturer will never say its OK to use their product in a way that is unfamiliar to them. I remember the
Airpax guy also told me they won't even recommend using their breaker in an EV. If they got a million $$ order from some EV
company for their products their PE's might just look at it real close and come up with the conditions that they would actually
recommend using their breaker. Are the PE and the manufacturer worn for not recommending using this methid? No. Is an
individual wrong for using it anyway knowing the limitiations, implications and safety precautions in spite of the engineering
deficiency? No.

As long as Tehben has a fuse AND a main contactor disconnect I think either of his breaker choices would suffice and be safe.

Mike,
Anchorage, Ak.



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## EVDL List (Jul 27, 2007)

> Morgan LaMoore wrote:
> > It won't work because the contacts won't switch at *exactly* the same
> > time. Imagine this: one contact opens a microsecond before the other
> > one. The second one is still closed, almost a short circuit, so if
> ...


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## EVDL List (Jul 27, 2007)

> Travis Gintz wrote:
> 
> > It wasn't making a blanked statement, I was saying unless its
> > in the spec, and the company recommends it, its not going to
> ...


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## EVDL List (Jul 27, 2007)

As long as everyone knows its not 100% correct 100% of the time, thats
what I was trying to state, as well as that its not safe practice
unless the manufacturer states it is, as with the square D. I was only
trying to prove that its not always a correct assumption, as I said in
one of my first emails about this subject that he should check the
cutsheet for the breaker he's using.


> And this is indeed worthwhile information for users of this specific part. It does not establish that it is incorrect practice to wire the poles of *any* Airpax breaker in series for increased voltage rating, but just that it is not recommended for this particular model (which, granted, is useful since this is the specific model Tehben mentioned ;^)

The engineer at Airpax actually said its not recommended with any of
their Magnetic breakers.... if that info matters at all. Just an FYI,
not another argument.

>
> Of course, we still don't know if the engineer has any experience with EVs or battery systems, or understood that the application uses the breakers as a *manual* disconnect and only requires that the breakers be able to open once under load in their lifetime.
>

He's done a handful of Battery backup systems for 200KV switch yards.
They're not small, but I see where you're going. He just stated that
the assumption that it will always work, is in fact incorrect and
should be looked into. Its not intuitive, and you know that as an
engineer...


> Do you understand the function of a breaker in an EV, and more specifically the function that Tehben described for the breaker(s) in his EV? It is not used as a protection device in the normal sense; it is used as a switch that is opened and closed manually without any load current to isolate the pack and/or break it into smaller voltage segments during service, etc. It may be opened manually under load in the event of a runaway condition if the fuse(s) and/or contactors fail to open first, however, this is an extremely rare situation and the breaker is only required to open under load like this once.

So its not being used as a breaker? I didn't see that until much
further on in the emails... so its never going to overload? and if it
does, its expected to be a fatal failure for the breaker? If so, just
make sure the blast path is safe.

> I understand; if you've been on the list for any length of time, you'll be aware that I am an EE and I'm often the guy expressing the same sort of opinions as you are here. ;^>

Good. I'm glad we agree on some things. I know you're saying that SOME
of the time it will work, and that most of the times you'll be just
fine in doing this. I just get tired of seeing people at the places
I've gone do some pretty messed up things. People have gotten hurt, so
I'm just on the safe side of things....

> There is, however, a saying to the effect that when even an experienced engineer states something to be impossible, they are almost certainly wrong. ;^>

Exactly what I was trying to state... but the other way.... someone
stated that this is a correct assumption, i was saying that its not a
correct assumption......100% of the time.

> As I've expressed, I do believe that if Tehben wants to be absolutely certain that his breaker(s) will perform reliably he should probably use a suitably rated breaker such as the Square D examples I mentioned. However, I am confident that the ganged Airpax breakers may happen to work just fine for the specified purpose despite the Airpax engineer's assertions. The key here is that if Tehben chooses to knowingly use the Airpax breakers outside of their intended/recommended ratings and application, then *he* must assume responsibility for testing to ensure that they will work. Fortunately, this is easy to do; once the EV is running, just manually flip the breakers off while pulling a few hundred amps and verify that they shut the system down and remain functional afterwards.

I agree 100% with that. He should be sure that its going to perform as
he wants it to perform. The airpax MAY work, but, as I've seen in many
destructive tests at GE's Hipot/HALT/HASS test lab at GE Energy,
things can fail fairly easily if used outside of their specs. So just
be careful. I'm glad you understand where I'm coming from.

> Cheers,
>
> Roger.

Yeah, Cheers to you too... its been an educational debate.

Regards,
Travis

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