I Need a 400V, 3-pole, 25A circuit breaker.....what would you use?

[Oscar]

As the title states. I need a 400V 3-pole circuit breaker. The 3-pole breakers at my local big box stores are rated at 240V. What would you use?

[jpump5]

480v.breaker from electrical supply store?

[M J D]

Amazon has plenty of offerings. Most common for the 3 pole are the type that mount on a dinse rail. The one I picked up for my rotary phase converter was rated for ,400 or 480 volt although I didn't need that high of a voltage rating.

[smithdoor]

If you using 240 volt then I use a 240 breaker add label 240 volts.
In America you can find 480 volt but cost is high.

Dave

As the title states. I need a 400V 3-pole circuit breaker. The 3-pole breakers at my local big box stores are rated at 240V. What would you use?

[Oscar]

480v.breaker from electrical supply store?

Thanks, I tried that. They are quick to try and pounce on someone that they don't see as a "regular". They said "special order. $300". I said, "oh ok, thanks", and walked out.

Amazon has plenty of offerings. Most common for the 3 pole are the type that mount on a dinse rail. The one I picked up for my rotary phase converter was rated for ,400 or 480 volt although I didn't need that high of a voltage rating.

Yep I had seen those. Just wondered how many have actually used those rail-mount types.

If you using 240 volt then I use a 240 breaker add label 240 volts.
In America you can find 480 volt but cost is high.

Dave

No, just no.

[jpump5]

I don’t know what the NEC has to say about this
but a 40amp. 240v. breaker on the primary side
of the transformer would trip when the secondary
side reaches about 23.5 amps.

[danielplace]

Some line-load options. Mount one in old disconnect box.

https://www.ebay.com/itm/30403427835...c767cc0280324c

https://www.ebay.com/itm/12227809980...440b817146cf7e

Same as above but has wrong picture of item,
https://www.simplybreakers.com/products/cqd325

Or go with a fusible disconnect,

https://www.homedepot.com/p/Siemens-...F361/205858167

[Willie B]

Have you specified what it goes in? Is this a single circuit application? As in a disconnect for a machine? 400 volt three pole is foreign to me. Nominally 480 Volt is very common.
No mater where you buy 480 Volt equipment it costs a good deal more than 240 V. There are used, and refurbished sellers.

[danielplace]

Have you specified what it goes in? Is this a single circuit application? As in a disconnect for a machine? 400 volt three pole is foreign to me. Nominally 480 Volt is very common.
No mater where you buy 480 Volt equipment it costs a good deal more than 240 V. There are used, and refurbished sellers.

It is a new Stel 300 400 volt machine running off single phase through a phase converter and 240 3 phase stepped up through a transformer to 400 volt for the welder.

I imagine he is looking for protection between transformer and welder. Stand alone line/load style.

https://weldingweb.com/vbb/threads/7...ng-transformer

Oscar likes electrical wizardry no doubt about that. Say what ? We don't have that many phases. We will make it. Say what ? We don't have that voltage. We will make it.

[whtbaron]

Ahhh.... I was thinking he'd bought an even bigger grinder...

[smithdoor]

I would avoid used aka refurbished.
If some gave me breaker I do refurbishing my self.

In America 400 volt is not used .
The 6 voltages that command in America [120, 208, 240, 277, 480 and 575 volts]. But breakers come in 120/240 277/480 and 600 volts.
Single phase is lowest cost , Then three phase 480 volt more triple price.

Dave

Have you specified what it goes in? Is this a single circuit application? As in a disconnect for a machine? 400 volt three pole is foreign to me. Nominally 480 Volt is very common.
No mater where you buy 480 Volt equipment it costs a good deal more than 240 V. There are used, and refurbished sellers.

[danielplace]

Even this route $150

https://www.homedepot.com/p/Siemens-...F361/205858167

https://www.ebay.com/itm/22442664475...0f2b08805d6317

[danielplace]

I would avoid used aka refurbished.
If some gave me breaker I do refurbishing my self.

In America 400 volt is not used .
The 6 voltages that command in America [120, 208, 240, 277, 480 and 575 volts]. But breakers come in 120/240 277/480 and 600 volts.
Single phase is lowest cost , Then three phase 480 volt more triple price.

Dave

400 volt is evidently what is used in Italy.

https://www.stelgroup.it/en/categoria-prodotto/tig-en/

When you are buying specialized equipment from companies that only make the unit you want in that voltage. Lots of equipment does not come in standard voltages for us.

Our company used to connect machines that put the hard coat on plastic optical lenses. It has been a while but want to say it was 365 volt 3 phase. They pulled some power as it is powering a lazer inside.

[smithdoor]

Looks great 👍. It what like using.
You use 240volt 3 phase but Oscar want higher cost 480 3 phase witch is ok.

Dave

Even this route $150

https://www.homedepot.com/p/Siemens-...F361/205858167

https://www.ebay.com/itm/22442664475...0f2b08805d6317

[danielplace]

Looks great ��. It what like using.
You use 240volt 3 phase but Oscar want higher cost 480 3 phase witch is ok.

Dave

Dave,
He wants it because that is what machine uses. 400 volt 3 phase.

He went 400 volt 3 phase. They do not make it in a 208 240 or 480 volt 3 phase machine.

He needs breaker/equipment for at least 400 volt often that means 600 volt equipment. Some breaker rated 480 would work too.

[Oscar]

Yes, I realize one rated at exactly 400V might be rare, but obviously so long as the voltage rating is that high, then it would/should work. I've gotten some good responses thus far, together with the not-so-good-responses that always accompany my electrical threads,

I imagine he is looking for protection between transformer and welder. Stand alone line/load style.

https://weldingweb.com/vbb/threads/7...ng-transformer

Oscar likes electrical wizardry no doubt about that. Say what ? We don't have that many phases. We will make it. Say what ? We don't have that voltage. We will make it.

You know me well.

I actually had considered the fusible disconnect, but I honestly just don't like how that looks, and I'd rather create/implement a 400-480V 3-pole breaker instead.

I would avoid used aka refurbished.
If some gave me breaker I do refurbishing my self.

In America 400 volt is not used .
The 6 voltages that command in America [120, 208, 240, 277, 480 and 575 volts]. But breakers come in 120/240 277/480 and 600 volts.
Single phase is lowest cost , Then three phase 480 volt more triple price.

Dave

No, just no....

[Willie B]

"I want unusual stuff nobody ever heard of. It has to be cheap."

A bit of a challenge, wouldn't you concede?

[Oscar]

So, someone recommended some breakers from Automation Direct, 480V 25A 3-pole C-curve trip curve 35mm DIN Rail Mount, that look like I could make them work.

Amperage aside, Any reason I could not use those 480V 3-pole breakers at 400V and 240V (3-ph of course)? What I know tells me the lower operating voltage (compared to the breaker voltage rating) should have no ill-effects, so long as they are sized properly to protect the wiring, etc. Thoughts?

[leightrepairs]

https://www.zoro.com/siemens-iec-sup...57/i/G6145264/

[danielplace]

So, someone recommended some breakers from Automation Direct, 480V 25A 3-pole C-curve trip curve 35mm DIN Rail Mount, that look like I could make them work.

Amperage aside, Any reason I could not use those 480V 3-pole breakers at 400V and 240V (3-ph of course)? What I know tells me the lower operating voltage (compared to the breaker voltage rating) should have no ill-effects, so long as they are sized properly to protect the wiring, etc. Thoughts?

Oscar,
That is correct. No problem using ones rated for more.

[Willie B]

I've never done it because of cost. In my world, a 240 volt 3 pole 25 amp breaker might cost $100. In 480 volt it might be $800.

If I understand your application, are you talking about 400V single phase? Would you need a 2 pole breaker for that?

[Oscar]

"I want unusual stuff nobody ever heard of. It has to be cheap."

A bit of a challenge, wouldn't you concede?

Well in that case , consider it another challenge taken down by the big-O ! And it's not that it has to be cheap, it's just that I have a pretty good idea of where I don't have to spend a fortune, and can make do with less, and so far I've been right. I mean, here I am, a hobbyist, with a garage full of gear that likely no other hobbyist has [the equivalent of], that shouldn't "be" if you ask those who told me "it won't work because blah blah blah blah....". People told me that I would fry all my 3-phase welders if I didn't get an "American Rotary" or "Phase Perfect" digital phase converter costing north of $10k. Guess what? My 3-ph welders are working just fine off of my $1400 RPC that is hand-made by Southern Phase Converters. My garage and house are still here, un-burnt, and the only smoke my garage has seen has come from welding, not from sparks because of careless wiring or some other misconstrued notion . So I guess you can say I love proving people wrong.

I've never done it because of cost. In my world, a 240 volt 3 pole 25 amp breaker might cost $100. In 480 volt it might be $800.

If I understand your application, are you talking about 400V single phase? Would you need a 2 pole breaker for that?

Nope, the welder is 400V 3-phase. The last pic I posted are the L1-L2, L1-L3, L2-L3 voltages coming out of the step-up 3-phase transformer (which is posted in my thread danielplace had hyperlinked in his post). So I guess you can say, your world and my world are on slightly different orbits.

[Willie B]

Well in that case , consider it another challenge taken down by the big-O ! And it's not that it has to be cheap, it's just that I have a pretty good idea of where I don't have to spend a fortune, and can make do with less, and so far I've been right. I mean, here I am, a hobbyist, with a garage full of gear that likely no other hobbyist has [the equivalent of], that shouldn't "be" if you ask those who told me "it won't work because blah blah blah blah....". People told me that I would fry all my 3-phase welders if I didn't get an "American Rotary" or "Phase Perfect" digital phase converter costing north of $10k. Guess what? My 3-ph welders are working just fine off of my $1400 RPC that is hand-made by Southern Phase Converters. My garage and house are still here, un-burnt, and the only smoke my garage has seen has come from welding, not from sparks because of careless wiring or some other misconstrued notion . So I guess you can say I love proving people wrong.



Nope, the welder is 400V 3-phase. The last pic I posted are the L1-L2, L1-L3, L2-L3 voltages coming out of the step-up 3-phase transformer (which is posted in my thread danielplace had hyperlinked in his post). So I guess you can say, your world and my world are on slightly different orbits.

Sorry, I skimmed over part of the thread.
I guess part of the difference is I buy 480 volt breakers for specific breaker panels (usually Square D). They better work first time with no failure rate, or it costs my customer a fortune in downtime. Sometimes I shop a bit for best price on a specific part number. Never had opportunity for a free standing circuit breaker. There, it's almost always a fused disconnect.
By all means, explore your choices. If a cheap solution doesn't work first time, as you said you are a hobbyist. Being held up a few days while waiting on a replacement isn't the end of the world.

[Munkul]

Over here, a 415v 3 pole breaker costs maybe £30.

Why are they so expensive over there?

As said, a higher voltage rated breaker is OK, they trip on current not voltage, as voltage doesn't affect the electromagnet portion in the breaker.

[smithdoor]

Oscar needs a 480 volt breaker.
He run the welder on 400 volts.

The American made breaker last for ever the Chinese has a shorter life.

Dave

Over here, a 415v 3 pole breaker costs maybe £30.

Why are they so expensive over there?

As said, a higher voltage rated breaker is OK, they trip on current not voltage, as voltage doesn't affect the electromagnet portion in the breaker.