# Aleart!!! Good deal on Airpax DC circuit breakers.



## ElectriCar (Jun 15, 2008)

If it's rated at 800A, each of the legs is rated at 800A so it will disconnect 4 800A circuits. 

Also the shunt trip function is a remote capability so you don't have to use your hand to open the circuits. That feature is used on kitchen hoods to enable the fire system to open the circuit electrically. You can use that feature if it works and you have the correct voltage. The shunt feature is basically a relay function so you have a relay/breaker combination.

EDIT: I hadn't seen the listing, just going from my experience and I'm pretty sure code says each leg must be rated for the full load for interrupting. You can't "gang" contacts for added amperage. Either this thing is rated at 4X800A or 4X200A. Couldn't find anything on it on the internet.


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## Jimdear2 (Oct 12, 2008)

ElectriCar said:


> If it's rated at 800A, each of the legs is rated at 800A so it will disconnect 4 800A circuits..


ElectriCar,

I have one sitting in my lap and it clearly states on the breaker that all of the legs on the input side and the output side must be jumpered with a buss bar to acheive 800 amps, the imbossed instruction also give the phisical dimensions of the jumper buss bars. The breaker is clearly made up of four individual units held together, side by side, with 4 long rivets. Ther breaker arms are also pinned together with connector blocks.



ElectriCar said:


> Also the shunt trip function is a remote capability so you don't have to use your hand to open the circuits. That feature is used on kitchen hoods to enable the fire system to open the circuit electrically. You can use that feature if it works and you have the correct voltage. The shunt feature is basically a relay function so you have a relay/breaker combination..


Yes I just think that is just super, I can install a remote BIG RED BUTTO to act as an emergency disconnect without getting high voltage near my hand (the shunt trip operates on 24 volts).



ElectriCar said:


> EDIT: I hadn't seen the listing, just going from my experience and I'm pretty sure code says each leg must be rated for the full load for interrupting. You can't "gang" contacts for added amperage. Either this thing is rated at 4X800A or 4X200A. Couldn't find anything on it on the internet.


Here is the Airpax part number

#JTEP-4-1REC4-33281-800DS

The JTP series appears obsolete, they seem to be replaced with JAE or JLE or JRE numbers, which are also parallel pole breakers. Go to this link and download the adobe file for the newer series parallel breakers, they show one with 6 individual breaker units rated at 1200 amps.

http://www.pocosales.com/Airpax.htm.

Like I say even if they don't work as breakers, for 45 bucks they make a great high amprage disconnect. 

Use the eBay link to look at what it is.

If it's as good a deal as i think, I would like to see some people in our forums get in on it. I got mine and I'm happy.


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## Tesseract (Sep 27, 2008)

ElectriCar said:


> EDIT: I hadn't seen the listing, just going from my experience and I'm pretty sure code says each leg must be rated for the full load for interrupting. You can't "gang" contacts for added amperage...


I'm pretty sure the NEC says you can't gang contacts, either, but this is a DC breaker rated for 100VDC (with the standard "code-minimum" interrupt ampacity of 10kA) so the code probably doesn't have much to say about it! 

I wouldn't try to use this with a battery pack voltage higher than, say, 150VDC, as the interrupt ampacity will probably drop below the typical short-circuit current capability of the average EV battery pack. Not to mention a pack composed of very low internal resistance cells like A123s, etc...


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## Jimdear2 (Oct 12, 2008)

Tesseract, Electricar,

Thank you all for your comments, I'm the mechanical half of our team so I will have to bow to your superior electrics/electronics knowledge. 

I read the info pages in the Airpax document I downloaded from this page.

http://www.pocosales.com/Airpax.htm

It sure seems to me that they are saying this breaker is a total 800 amp circuit breaker consisting of 4 paralleled 200 amp breakers. 

Please do me a favor and help out a electronics dunce, open the file and read through it and if you have the time let me know where I went wrong. I hate to drag stuff out but I want to learn.

The catalog (another downlad from this page) lists the JTEP breakers as current products used in the telecommunications industry.

Below is a copy from page 3 of the Airpax document I downloaded.

*General Description*​​​​​​​mid-trip handle available for visual
identification of fault-tripped​
circuit breakers
optional internal low voltage
shunt to meter current
(single and multi-pole units are
dimensionally equivalent in depth)
terminal options for design
flexibility in various applications
multiple trip time delays for
application flexibility
electrical and mechanical actuated
auxiliary switch options for
external monitoring of circuits
reduced voltage drop through
the circuit breaker vs. other
circuit protective devices

​​​​​​*Number of Poles*​1, 2, 3, 4, 5, 6

*Current and Voltage Ratings*
100 to 250 amperes, 160Vdc
100 to 250 amperes, 125/250Vdc
100 to 250 amperes, 65Vdc
275 to 800 amperes, 160Vdc
(paralleled poles)
275 to 1200 amperes, 65Vdc
(paralleled poles)

​​​*Interrupting Capacity*​10000 amperes, 160Vdc
10000 amperes, 125/250Vdc
50000 amperes, 65Vdc

*Approvals*
UL 489 Listed
UL 489A Listed
CUR Certified

Single-pole ratings: UL489, 250 amps max at​
160 Vdc, 10,000 amp interrupting capacity
and 250 amps max at 65 Vdc, 50,000 amp
interrupting capacity. Multi-pole ratings: UL
489A, 800 amps max at 160 Vdc, 10,000 amp
interrupting capacity and 1200 amps max at
65 Vdc, 50,000 amp interrupting capacity.


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## ElectriCar (Jun 15, 2008)

I was about to ask if it were UL rated. Looks like you got a good deal there. Have you determined the voltage required to operate the shunt feature?


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## Tesseract (Sep 27, 2008)

Jimdear2 said:


> Please do me a favor and help out a electronics dunce, open the file and read through it and if you have the time let me know where I went wrong. I hate to drag stuff out but I want to learn.


I'm not sure where you went wrong, or that you even did?! The document says you can use the breaker at 160VDC (so, a little higher than what I guessed) but you have to limit the trip current to 800A (which suggests it is adjustable) and that the interrupt capacity is 10kA at that voltage. This seems eminently suitable for an EV application, as long as you need less than 800A of battery current at 160VDC or less and the internal resistance of the pack and all wiring is more than 16 milliohms... Shouldn't really be an issue unless you are using massively parallel banks of cells and/or running at rather low voltages (but then the interrupt rating of the breaker goes up, too, so still not much of an issue).


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## DIYguy (Sep 18, 2008)

Remote shunt trip is an excellent feature. I use this on my conversion and it works great.

cheers,
Gary


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## Jimdear2 (Oct 12, 2008)

ElectriCar said:


> I was about to ask if it were UL rated. Looks like you got a good deal there. Have you determined the voltage required to operate the shunt feature?


ElectriCar,

I'm glad you all are starting to think this might be usuable. I was getting a bit worried and wondering if I was reading one thing and understanding another.

The documentation I've seen say that the shunt (aux) coil is 24 volts. I have put the thing back into the shop, When I get back out there I'll check what it says on the breaker. If It's different I'll post the information.



Tesseract; said:


> I'm not sure where you went wrong, or that you even did?! The document says you can use the breaker at 160VDC (so, a little higher than what I guessed) but you have to limit the trip current to 800A (which suggests it is adjustable) and that the interrupt capacity is 10kA at that voltage. This seems eminently suitable for an EV application, as long as you need less than 800A of battery current at 160VDC or less and the internal resistance of the pack and all wiring is more than 16 milliohms... Shouldn't really be an issue unless you are using massively parallel banks of cells and/or running at rather low voltages (but then the interrupt rating of the breaker goes up, too, so still not much of an issue).


Tesseract,

Thanks for reviewing the information, you are one of the people on the site I pay close attention to. I feel a lot better now that it appears I really understood what I was reading (amazing). Even better I understood quite a bit of your response as well.

We are going to be using this breaker on a 150 cell 50S3P Headway pack of 38120P cells. The pack will never be charged above 3.5 volts per cell (each parallel 3 cell buddy pack will have it's own 3.5 volt charger) so the pack will be 175 volts nominal right after charging and they batteries seem to normalize to 3.4+- volts (170 volts), only a couple of percent high. I sure hope there is a bit of cushion built in. Of course, under a load, with voltage sag, it will be more like 125 -130 volts.

Right now the the Headway battery pack I am in the process of building will be 50S/3P. Each 3 cell stack will be buddied. I'm drilling all of the buss connectors to eventually take 4 cells per buddie pack. So far I have all 51 pieces of copper cut to size and around 185 of the 255 holes drilled. The batteries arrive Tuesday. We are starting off with a 600 amp pack and will eventually (next year) increase to 4P and 800 amps. 

The 38120P cells are supposed to be able to handle up to 25C. The couple I've tested come close. 

With 50 cells in series I think we can exceed 16 milliohms resistance. So it looks like I have a real winner. Next the lottery?????

Thanks,
Jim




DIYguy; said:


> Remote shunt trip is an excellent feature. I use this on my conversion and it works great.
> 
> cheers,
> Gary


Gary,

I really like the idea myself. A question for you, 

Do you trip the breaker often with the shunt? I couldn't find a cycle life for the shunt disconnect.

Being able to put the breaker into an enclosure away from dirt and inquisitive hands sounds like a good idea. Being able to install multiple trip switches in parallel also sounds great. 

For us it will be one controlled by a BIG RED BUTTON on the dash and second the breakaway tether would be another, if tractor breaks away from the sled, it trips the breaker instead of opening the main contactor. Makes the wiring simpler fewer components to go bad, could do both as well.

To all of you, thanks for responding.

I sure hope some others from DIY gets one of these before they are gone, for $45.00 bucks,ther hard to beat.

Jim


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