Are solid state circuit breakers any good?

H. Paul Shuch is a Light Sport Repairman with Maintenance ratings for airplanes, gliders, weight shift control, and powered parachutes, as well as an independent Rotax Maintenance Technician at the Heavy Maintenance level. He holds a PhD in Air Transportation Engineering from the University of California, and serves as Director of Maintenance for AvSport of Lock Haven.

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JimParker256
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Re: Are solid state circuit breakers any good?

Post by JimParker256 »

I'm with Sling on this one... I'd just prefer to have normal circuit breakers or fuses. My plane doesn't have electric trim (the trim wheel is just fine for me).

But having said that, I've heard very little "bad" about the Vertical Power units. I think there were some issues early on, but those are long-since resolved. Over on the RV forums, they seem to be almost universally used for new airplanes (except the RV-12 E-LSA, where Van specified automotive-style blade fuses).

The one "caveat" I've heard (strictly 2nd- and 3rd-hand information - no personal knowledge of my own) is that some folks with older units have reported that VP is no longer supporting those older models, and the only course for them is to replace their units with a new model if they encounter problems they cannot resolve themselves. (Another "non-issue" with CBs and fuses...)
Jim Parker
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Re: Are solid state circuit breakers any good?

Post by fatsportpilot »

The thing that attracts me to VP is the monitoring that it has which lets it report problems. I think basic thermal circuit breakers are just fine but they can't tell me how many amps is going through each wire and whether a bulb failed open or shorted.
Sling 2 Pilot
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Re: Are solid state circuit breakers any good?

Post by Sling 2 Pilot »

The issue i have, if the box goes bad, you have the potential to loose everything. Not so with individual breakers. The monitoring is nice, but IMO, unwarranted for my application.
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ShawnM
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Re: Are solid state circuit breakers any good?

Post by ShawnM »

Nothing beats a good ole' manually resettable circuit breaker. I recently updated all mine to the Klixon 2TC2 series. If any one of them gives me a problem I can easily replace it. If I have an issue in flight I can VERY QUICKLY reach over and pull it out. Easy peasy !!

I'm a gadget guy and love tech but I do have to set limits somewhere. :mrgreen:
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Re: Are solid state circuit breakers any good?

Post by Wm.Ince »

I subscribe to "keep it simple."
That goes right along with "if it ain't broke, don't fix it."
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Re: Are solid state circuit breakers any good?

Post by drseti »

Wm.Ince wrote:"if it ain't broke, don't fix it."
No, Bill. As a mechanic, I subscribe to the adage "if it ain't broke, break it. Then charge to fix it."
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
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JimParker256
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Re: Are solid state circuit breakers any good?

Post by JimParker256 »

drseti wrote:
Wm.Ince wrote:"if it ain't broke, don't fix it."
No, Bill. As a mechanic, I subscribe to the adage "if it ain't broke, break it. Then charge to fix it."
LOL Paul, you must have been talking to my old mechanic!
Jim Parker
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Re: Are solid state circuit breakers any good?

Post by Wm.Ince »

Good one, Paul!! :D
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Re: Are solid state circuit breakers any good?

Post by fatsportpilot »

Sling 2 Pilot wrote:The issue i have, if the box goes bad, you have the potential to loose everything. Not so with individual breakers. The monitoring is nice, but IMO, unwarranted for my application.
That could also be true with individual breakers because a failure in the bundle of high current wires that go through the firewall is a single point of failure. I hope VP is smart enough to design the box so a failure in software would not bring the whole box down. I'll call the company and ask them what happens if the microprocessor inside fails and how that affects the power flowing through ie whether it's a fail open or fail closed circuit.
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Re: Are solid state circuit breakers any good?

Post by fatsportpilot »

Wm.Ince wrote:I subscribe to "keep it simple."
That goes right along with "if it ain't broke, don't fix it."
Usually a good idea but I'm already going with an EFI engine and a glass cockpit which is where all the complexity will be. Carbs and floats are simpler than ECUs and fuel injectors, and vacuum pumps and gyros are simpler than complex computerized EFIS and ADAHRS sensors. But I still think steam cockpits give you less situational awareness than glass cockpits and solid state gyros (are they really solid state if many of them have got a dither motor?) are more reliable than vacuum pumps and mechanical gyros. Simple is usually best and I love the KISS principle but sometimes more complex is safer after all.
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Re: Are solid state circuit breakers any good?

Post by Sling 2 Pilot »

fatsportpilot wrote:
Sling 2 Pilot wrote:The issue i have, if the box goes bad, you have the potential to loose everything. Not so with individual breakers. The monitoring is nice, but IMO, unwarranted for my application.

That could also be true with individual breakers because a failure in the bundle of high current wires that go through the firewall is a single point of failure. I hope VP is smart enough to design the box so a failure in software would not bring the whole box down. I'll call the company and ask them what happens if the microprocessor inside fails and how that affects the power flowing through ie whether it's a fail open or fail closed circuit.
My scenario, Not likely. Your scenario...much more likely.
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Re: Are solid state circuit breakers any good?

Post by Warmi »

fatsportpilot wrote:
Wm.Ince wrote:I subscribe to "keep it simple."
That goes right along with "if it ain't broke, don't fix it."
Usually a good idea but I'm already going with an EFI engine and a glass cockpit which is where all the complexity will be. Carbs and floats are simpler than ECUs and fuel injectors, and vacuum pumps and gyros are simpler than complex computerized EFIS and ADAHRS sensors. But I still think steam cockpits give you less situational awareness than glass cockpits and solid state gyros (are they really solid state if many of them have got a dither motor?) are more reliable than vacuum pumps and mechanical gyros. Simple is usually best and I love the KISS principle but sometimes more complex is safer after all.
Electronics, despite their complexity , are much less likely to fail than mechanical devises because failures are generally result of wear and tear and your typical SOC has 0 moving parts - in that regard it is much simpler than the simplest mechanical device.

Modern cars , despite being incredibly complex, are much more reliable than anything in the past ... even your personal phone, while being orders of magnitude more complex ( compared to say a carburetor ) and being pretty much constantly abused is essentially a maintenance free device.
Flying Sting S4 ( N184WA ) out of Illinois
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