Digital Circuit Breakers

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gar

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190522-0446 EDT

See https://pdfs.semanticscholar.org/d79c/6d6c1a8c8fa1e620edae3865076f773b6803.pdf

Look at SiC voltage drop compared to an electromechanical switch. Possibly at least 100 times more power loss in the SiC switch compared to a silver contact switch for the same switched current.

In the early 1960s I was involved in the early demonstration of an electronic breaker. I used SCRs, these have high voltage drop when on, about volt or so, but lower than SiC devices. Silver contacts are in the millivolt range.

For a lot of purposes I don't think a solid-state power switch is better than electromechanical. But electronic control of the switch has some great advantages.

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J

JMBreaker

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They aren't the only one

They aren't the only one

synchro said:
These breakers have recently gotten UL approval.
But it will probably be awhile before we see them in Home Depot :

https://www.google.com/amp/s/spectr...-the-era-of-digital-circuit-breakers.amp.html
Click to expand...


ABB unveiled this 1p 1500VDC breaker for solar and energy storage applications a few months ago. Seems like they may work for certain niche markets.

https://new.abb.com/news/detail/184...ology-for-renewables-and-next-gen-power-grids
 
synchro

synchro

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Agree that solid state switches can't match the low losses of mechanical contacts. I see it's becoming common to see SCRs combined with mechanical contactors inside an ATS to leverage the best advantages that each one has.
SiC can provide faster switching than SCRs and it has no restriction on when it can turn off (vs. SCRs that stay on till the next zero crossing). So I'm sure there will be new applications where SiC will excel.
 
ron

ron

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synchro said:
Agree that solid state switches can't match the low losses of mechanical contacts. I see it's becoming common to see SCRs combined with mechanical contactors inside an ATS to leverage the best advantages that each one has.
Click to expand...
We see this combination for UPS static bypass switches, but for static transfer switches, it is mostly just the solid state portion.
 
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gar

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190522-1601 EST

synchro:

You can not shunt a solid-state switch with a mechanical contact in a circuit breaker to reduce steady state power loss, and still expect to obtain a faster trip time than the trip time of the mechanical contact.

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ron

ron

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gar said:
190522-1601 EST

synchro:

You can not shunt a solid-state switch with a mechanical contact in a circuit breaker to reduce steady state power loss, and still expect to obtain a faster trip time than the trip time of the mechanical contact.
Click to expand...

For some UPS static bypass switches, they use the solid state switch to make the fast transfer, then close the parallel mechanical bypass contactor, then open the solid state switch. The transfer back to UPS double conversion is deliberate, so it will close the solid state switch first and reverse the process.
 
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gar

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190522-1554 EDT

ron:

Parallel contacts are fine for a turn on application, but that is not a circuit breaker application.

Now consider a turn off application. Virtually any loading on a switch has some inductive component. What happens to the voltage across a switch when you open a circuit to a load while current is flowing? So what is the result of instantaneous tripping?

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A

Andy Delle

Senior Member
Location
Los Angeles CA
Also semiconductors can fail in a short condition. How many times have you replaced a light dimmer that won't dim, just full brightness all the time! That's because the Triac or SCRs have failed shorted.

At a minimum these solid state breakers are still going to have an internal series fuse or I would guess they never get approvals.
 
romex jockey

romex jockey

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Vermont
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electrician
In the May trade rag>>>

https://www.leviton.com/en/products/residential/load-centers

Take power to new heights with the award-winning Leviton Load Center – the industry’s most intelligent circuit breaker system. With optional Internet connectivity, an all plug-on design for easy installation and safety features that exceed the UL standard, the Leviton Load Center offers unparalleled energy management of your home's electrical system.
Click to expand...

Smart_LC_Callouts.jpg


~RJ~
 
hbiss

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
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EC
What's a smart home without a smart circuit breaker? Manage your home’s electrical circuits with Leviton Smart Circuit Breakers and the intuitive My Leviton app on a smartphone, tablet or desktop. View real time energy consumption and trends, including total energy cost per month. Get alerts when a circuit breaker trips, or even trip one remotely – and so much more.


Click to expand...

Gee, in my over 70 years I never really gave a thought about my breaker panel unless, on the rare occasion, something tripped. So now Leviton is giving the Millennials one more reason to be glued to their damn phones for something as useless as social media.

Want to know how much you are using? Don't you get a friggin bill every month??? Going to be more accurate also.

-Hal
 
M

MAC702

Senior Member
Location
Clark County, NV
"Manufactured to a higher standard?" Where have I heard that "higher standard" lie before? :blink:

Higher standard does not mean higher quality, and is usually indicative of greater potential for problems in the first place.
 
mbrooke

mbrooke

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romex jockey

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
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