When I was running 15kv underground coaxial power cables out in the middle of The Pacific, the guys working at the island's power plants discovered that a product, LPS 3 Premier Rust Inhibitor sprayed on the connections of all their high, medium and low voltage connections kept them corrosion free in the salt water environment. ^_^
TDD
Thanks for the head up. I can get LPS3 at a hardware some what near me. I replaced a circuit panel box for a friend, a couple years ago. We took out a FPE Stabloc, and put in something modern. Probably saved his life. And his wife and two kids. I could have sprayed all the neutrals and aluminum connctions with that stuff. Well, next time....
When I was running 15kv underground coaxial power cables out in the middle of The Pacific, the guys working at the island's power plants discovered that a product, LPS 3 Premier Rust Inhibitor sprayed on the connections of all their high, medium and low voltage connections kept them corrosion free in the salt water environment. ^_^
TDD
It also reduces combined voltage drop by up to half if both circuits are equally loaded because the current on the neutral is virtually zero. That is another reason to use them on long runs.
They do make 2 pole AFCIs now to replace the two pole breaker you should be using on a multiwire circuit.
replaced a circuit panel box for a friend, a couple years ago. We took out a FPE Stabloc, and put in something modern. Probably saved his life. And his wife and two kids. I could have sprayed all the neutrals and aluminum connctions with that stuff. Well, next time....
The LPS 3 dries to a waxy film that can be easily removed. I've used it in motor connection boxes on cooling towers to prevent corrosion. ^_^
TDD
I wonder if that would slow down the rust that eats our vehicles. From road salt.
Would it be suitable to spray on aluminum high amperage feeder wires, in circuit panel boxes?
The LPS 3 dries to a waxy film that can be easily removed. I've used it in motor connection boxes on cooling towers to prevent corrosion. ^_^
TDD
How does something dry wet? If it remained wet, it didn't dry, no? ;-)
LPS3 lasts a year outdoors so they claim. I spray boiled linseed oil on some auto parts on vehicles. I don't how that would stack up on electrical connections. Might catch fire.
Greg
Just saying - over 40 years with "series 2" aluminum wiring and standard devices (not CoAlr or the previous version of "aluminum compatible" )and not a single sign of corrosion, degradation, or any other problems when replacing all the devices with CoAlr to satisfy insurance inspection. Never a single problem other than 2 outlets that lost contact tension and were replaced about 7? years ago.
Or the brushes "bounce" on ANY brush motor. I've heard of problems running vacuum cleaners, older sewing machines, handheld mixers, and food processors, among other devices. Anything that can produce multiple sparks. Even unplugging a lamp while it is turned on - if you don't pull the plug quickly - can trip an AFCI
replaced a circuit panel box for a friend, a couple years ago. We took out a FPE Stabloc, and put in something modern. Probably saved his life. And his wife and two kids. I could have sprayed all the neutrals and aluminum connctions with that stuff. Well, next time....
Just remember - if you use LPS and there IS an arc, you have a fire. That stuff is pretty flammable. It is a light petroleum base. A bit of a "catch 22".
Oh, that puts my brain in spain, in pain. Far too philosiphical for me.
How does something dry wet? If it remained wet, it didn't dry, no? ;-)
A gfi has a circuit. Circuits can catch fire. I saw one circuit with a MOV, which can catch fire. They should have fusing on the circuits, which I doubt many have. The real question is the quality of the box, but if the front flares up, what are you going to do.
Greg
Thanks. This all seems so simple now, I wonder why I didn't understand it the last time. ~~~~~!
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All are certainly possibilities. So, there's some way in the AFCI sensing circuit to adjust the level of RF that trips the AFCI. I wonder if there are any AFCI products out there where that adjustment can be changed within a range to maintain a level of protection while minimizing nuisance tripping on noisy systems.
Tomsic
*About a year ago a customer called me about a circuit breaker that kept tripping when they used their treadmill exercise machine. The breaker was an arc fault type and the problem only occurred when the machine was shut off . Long story short, I found that by using an extension cord to power the treadmill from the same receptacle and circuit, the problem stopped.
In general, if a house circuit does not need GFCI protection it needs AFCI protection.
AFCIs include ground fault protection at about 30mA (GFCIs are 5mA). I suspect that without the ground fault protection the neutral wouldn't have to be wired through an AFCI.
Mixed neutrals and "anomalies" can cause other problems.
If someone wants to add AFCI protection, another option is AFCI receptacles - Leviton is supposed to have one (maybe other manufacturers?). Like a GFCI receptacle, an AFCI receptacle will protect what is plugged into it, and what is wired downstream through the receptacle. If all the load is at the receptacle or downstream it should protect the upstream wiring from series arcs (loose connections) but not parallel arcs (H-N & H-G arcs).
Under the 2011 NEC, for new circuits protection can be an AFCI receptacle installed as the first device with the rest of the circuit wired through it, but the code is rather restrictive about the wiring method from the panel to the AFCI receptacle. The AFCI receptacle can be mounted next to the panel (which can protect fused circuits).
For extensions to existing circuits, where the extension is in areas that require AFCI protection, that protection must be provided. It can be done with an AFCI breaker, or an AFCI receptacle can be installed where the extension takes off (or upstream from that point).
AFCIs look at the arc "signature", which is more than just RF content. Last I heard detection is for arcs 5A or higher.
Great idea. Add a little "R", "L" and "C" with an extension cord or line filter on a noisy load and attenuate the RF before it gets back to the AFCI.
Tomsic
A 10 foot extention cord coiled up beside the treadmill makes a pretty good choke.
I agree that the "scuttlebutt" was not favorable regarding nuisance trips. I was thinking about installing them, too, a while back but after all the bad luck I had with the first CFL's to hit the market, I decided to wait out being a pioneer for arc fault technology.
That's fascinating. I just learned that the local water authority monitors the rebar in their 60"+ concrete water mains acoustically. When one of the reinforcing bars snaps, it sends out a unique sound that is monitored by a series of microphones throughout the system and they then replace the pipe section.
The only problem is that the most recent break occurred where there was no rebar in one of the large joints. Who would have thunk of monitoring the RF emissions of an arc or the sound of snapping rebar? As for the AFCI, it makes sense because the wire leading to the arc must act as a fairly efficient antenna. I always wondered how an AFCI could differentiate between normal current draw and the creation of a dangerous arc. Does that mean you can't use an arc welder on an AFCI protected circuit?
I can live with a breaker popping when a light bulb pops. I've had normal breakers do that. I assume that like GFCIs (Clare used the term CFCI - is there a difference?) as they get more feedback from users, they tweak the design to handle those false triggers better. My first GFCI used to trip like crazy for no reason. The most recently bought ones hardly ever trip. I got so suspicious I even bought a GFCI plug-in tester to make sure they were working. (They were.)
Somewhere out there there's information about nuisance trips and whether they were over-hyped to begin with or whether the earlier units just couldn't detect them as well as the newer units do. Our resident sparkies should know.
As for AFCI's, my understanding (from way back when) is that they were recommended for bedrooms and bathrooms where a high current device like a space heater or a hair dryer could create an arc big enough to start a fire very quickly. I can attest that a space heater plugged in only partially can create enough heat to melt plastic. DAMHIKT. (-:
I once took apart a six-outlet extender that was getting warm to discover the copper cross bars were press-fit and had become loose and were starting to blacken at the place they were joined. I also noticed that these old press-fit six way outlet extenders had two copper bladed plugs and were electrically cross-connected. The one I bought to replace the burned-up one had only one live plug. The other was plastic and just acted as a stabilizer. I suppose that's to prevent someone from plugging the extender into an extension cord and not an outlet. That would make the second plug electrically live and exposed.
There's really no need I can see to cross-connect the two plugs to the six outlets. It could be set up so that each plug feeds only three of the six outlets and then you could plug it into an extension cord without creating an electrocution hazard. Maybe it was an economy thing. After all, not putting a second copper plugs has to be cheaper if you're making 10,000 of these things. The best design would be to use two isolated plugs because that way something like a remotely switched lamp outlet would still work as it should.
AFCI look for current components that are higher than power line frequencies. Wires are not antennas. And it is not just the higher frequencies. AFCIs look for arc "signatures" to separate normal arcs from "bad" arcs. My guess is they use digital signal processing but I don't know.
The inductance of a welder transformer might hide a welding arc.
The NEC originally required AFCIs only for bedrooms. Those AFCIs could only detect "parallel" arcs - H-N & H-G. Arcs might have to be 60A to be detected (series arcs would be 15 or 20A max). The idea, I believe, was largely to detect arcs between wires in extension cords which were walked on or abused in other ways.
AFCIs now detect arcs at a 5A level. That can detect a series arc (loose connection).
And AFCIs include ground fault detection at about 30mA. If there is a ground present in a cord an arc is likely to include leakage to ground soon. Arcing at a receptacle can also wind up with leakage to ground.
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