Douglas Hansen

Franklin systems have propagated since 1752 because they work. UL 96 provides listing for components of lightning protection system, and NFPA 780 provides installation guidelines. NFPA 780 is dealing essentially with passive lightning protection using the principles espoused by Franklin. Early streamer emission and dissipation array systems have been attempted and have no real record of success, whereas passive protection has worked for a long time. Lightning is an alternating current that travels in steps, in both directions from earth to sky and back. The placement of air terminals per NFPA 780 is intended to provide an umbrella of protection. It uses a "rolling sphere" model for this, where air terminals on top of a building are of sufficient height such that a sphere with a 150 foot radius would roll over the terminals without touching the building. By placing them at those intervals, the "step" of the lightning strike would reach a terminal before it would reach the building structure. While some aspects of lightning protection are understandable, there are also things like ball lightning that defy explanation. NFPA 780 has an interesting disclaimer: "Lightning is a stochastic, if not capricious, natural process. Its behavior is not yet completely understood. This standard is intended to provide requirements, within the limits of the current state of knowledge, for the installation of those lightning protection systems covered by the standard."

I think WJ once described these sorts of documents as a puzzle rather than a report. I find that attempting to sort it out is painful. The information is consistently cloaked behind the attempt to first characterize its significance, or lack of same. I would not be pleased if I were a client and got this in return for my money. If the unique definition of a GFCI didn't disappoint me sufficiently, the advice to "Buy an old crescent wrench at a garage sale" certainly did the trick.

OK, you really are displaying symptoms of something. "Charles Laws?" Did you mean Hubert Laws or Charles Lloyd? And let's not leave off the great soprano players, Steve Lacy and Gary Bartz. Bartz is still alive and blowing, while also holding down a professorship at a music school in Ohio. My favorite cat.

Kurt - you never cease to amaze me. That's a pretty fine listening list there. The closest I came to hearing Zep was shortly before the group was formed. At the old Fillmore Auditorium in San Francisco, Bill Graham was fond of booking first rate jazz acts for the education of his audience. In the late 60's, I went there to see Cecil Taylor. The warmup act was billed as "The Yardbirds" which at that stage consisted of Jimmy Page and some irrelevant accompaniment. Cecil Taylor was amazing.

Yep - I'm on the menu.

The codes mention roofing nails and a requirement that they comply with ASTM F1667 (which also includes some staples). If the roofing manufacturer wants to have staples approved under the provisions for Alternative Materials, Design, and Methods, they can do so by obtaining an ICC Evaluation Service Report. If you look on GAF's web site, they will tell you they don't ever recommend staples. Then if you look here http://www.gaf.com/Roofing/Residential/ ... 321-v4.pdf you will find an ICC ES report that does allow staples for that very manufacturer's product. Most of the problems with staples are the result of poor installation. If someone takes the time to get the staples in the correct orientation, in the proper nailing zone, and sets the pressure properly, they can be OK. Odds are you will find lots of other problems with their placement, not just the fact that they are staples.

We are very happy with Dropbox. 1st couple GB are free. I think I pay $100 a year for 50 GB.

The rule on protection where entering a panel was new to article 312 in 2002. It is a very specific case that is an exception to the basic rule that each cable be secured to the panel. NM cable and other types of cable are allowed to be pulled through raceways as long as they meet the fill requirements. You could pull romex through EMT all through your house if you were so inclined. It isn't prohibited by the rules for NM or for EMT. Note 9 to Table 1 in chapter 9 tells us to count the multiconductor cable as a single conductor for fill purposes (not for derating) and to use the long dimension on elliptical cables.

I converted to pre-twisting about 3 years ago, except when connecting stranded to solid. I grab the ends of the wires with the sidecutters, twist, and cut off the end tails. Then I add the wire nut, and twist it by hand until the insulated portions of the wire also show a twist. When connecting stranded to solid, I lead the stranded a bit longer and allow the wire nut to do the twisting. When using a tool to twist the wire nut, it is really easy to overdo it and drive the wire right through the end of the plastic.

Since 1/1/11, California uses a residential code based upon chapters 1 - 10 of the IRC. The Building Standards Commission publishes a free training guide explaining California's codes: http://www.documents.dgs.ca.gov/bsc/Tit ... gGuide.pdf

Follow through to the "certification marks" link in your link above. You will see that what this company is putting on the product is not the listing mark for something that is listed for the U.S. You might also look in the UL White Book for the examples of the mark attached to products listed for both Canada and the U.S. Reciprocity on products is case-by-case, not a blanket "approval." An example of something else that has a CSA mark that isn't allowed in the U.S. would be Federal Pioneer breakers. The other tell-tale sign is that they say it is "UL approved." A listing is not an approval, and UL does not allow the word "approved" to be used in that context. Next is that it doesn't use the version of the UL symbol that is present when UL has evaluated something. The U is not on the same line as the L in a legitimate marking. This thing is not listed and should not be allowed in the U.S. I am visiting UL next week on other business, and will bring this up with them. If they say they are happy with this, I will let you know, though I expect that won't be their response. A similar product line, "designer faceplates," were removed by changes in the 2008 NEC (elimination of exception 2 to 406.4D). The concern there was whether a faceplate could prevent full insertion of the plug. It might be a concern here too, since the final depth from the adjacent wall face depends upon the drywall install.

A very interesting product. The statement that the product is "approved to UL standards by CSA" is very misleading. A correct translation is "This product is not listed by UL. It has not been found to be in conformity with UL standards, and its use does not comply with NEC 406.3(A) which requires receptacles to be listed."

My house in Palo Alto had one of these, a recessed laundry room subpanel. One of the breakers wouldn't reset, and someone had double-tapped another breaker to keep things going. After I moved in, another double-tapped breaker failed, so I replaced it with a new surface mounted box over the old one, pulling the wires into the back of my new one. The house was built in 1938. I was a bit surprised that it had breakers at that age. The main outside and the other outside circuits were fuses.

Smart Meters are a very emotional issue in this part of the world. PG&E (our local utility, and an acronym for "Pigs, Greed & Extortion") has not exactly been forthcoming about why these things are so necessary. The idea that they will enable real-time monitoring of power consumption to more efficiently manage the grid is nonsense. First off, most substations don't have automatic tap-switching to regulate current flow on the line. Next, even if they did implement automatic tap-switching, the only data they need could come from one device at the end of each line, not a smart meter on everyone's house. PG&E is the company that brought us the San Bruno gas explosion, among numerous other tragedies, and pretty much behaves like the poster child for corporate irresponsibility. What most folks are freaked out about here is the potential health issues from yet another radio transmitter, one close to the frequency range of cell phones, short wave, etc. PG&E strong-armed their way past any open discussion of the issue, branding anyone that failed to trust them as a kook. When they started installing smart meters in Marin County, citizens would form human barriers and blockade their trucks from entering rural property (they started in the western part of the county). As a result, the first meters were put in literally at the point of a gun. Every governmental jurisdiction in Marin County issued a moratorium on installing more smart meters, and PG&E responded by saying they were not subject to local laws. My local state congressman (Jared Huffman) put in some legislation requiring PG&E to hold off and allow more studies and to allow folks to opt out. After Huffman's legislation was introduced (and before it was passed), they offered to allow us to opt out for a $300 opt-out fee, a $30 a month meter-reading fee, and a $300 end fee. They said this was necessary to recover their investment in Smart Meters. That plan too was quashed thanks to public outrage (the one thing PG&E is still capable of generating). In the meantime, PG&E spent $65 million on a statewide ballot initiative to prevent local groups from forming energy cooperatives, such as the Marin Energy Authority, which will be replacing many of PG&E?s functions in our area. PG&E's initiative lost at the polls, despite outspending the opponents by a drastic margin. In case anyone is curious, here is a white paper from the company that manufactures the smart meters that PG&E uses: http://www.silverspringnet.com/pdfs/Sil ... -Final.pdf They claim these things work much better on an unlicensed spectrum. Why am I not reassured? So back to the point. I called up PG&E a few months ago and asked them if they knew anything about smart meters interfering with AFCIs. To my surprise, they said yes, and that they had "2 kinds of smart meters, including one that didn't interfere with AFCIs." I asked them what I would have to do to assure that I got that type, and they said they didn't know and would call back. They never did. As part of my participation in the local IAEI chapter, I interact with PG&E's representative pretty routinely. He knows NOTHING about smart meters and AFCIs. He also didn't know there were two kinds of smart meters. The same is unfortunately true for some of the other smaller municipal-owned utilities in our area. Maybe there really aren't two kinds, and it is just something that PG&E's flacks have been trained to say to people like me. Bottom line, I don't know if these will cause a problem with AFCIs. There are many reports of the first ones causing nuisance tripping in houses in San Jose. My hunch is that the problem is going to be found on the older branch-feeder AFCIs, since they seem so inferior in other regards to the newer "combination" AFCIs, but who knows? The only thing of which I am certain is that PG&E is not telling us the truth on multiple levels.

Hi Robert First off I applaud you for doing some checking before attempting something for the first time. I do wonder if you came to the best place for that. This forum is used primarily by inspectors, and not by electricians or DIYs. There are several excellent electrical forums out there, including Mike Holt's forum, where you can expect to hear a lot more on this question. http://forums.mikeholt.com/ My first question would be why you are bringing this underground. We normally see that only with pad-mounted transformers, not overhead conductors, though I'm sure you must have a reason. Next, the 2 inch conduit would meet the code for your 4/0 wires, but it may have to also comply with utility rules. Here in my part of California, our utility has a minimum 3-inch size for all underground services. Also remember that your 2 feet underground means 2 feet of cover on top of the conduit, not 2 feet from grade to the bottom of the ditch. If you're going to use 4AWG copper to your ground rods, you don't need conduit for them. You could use 6AWG (even though you have a 200-amp service, grounding electrode conductors that solely serve rods never have to be larger than 6). You still would not need conduit if you ran the conductors onto your posts or strapped to your riser. You may need expansion fittings on the pole, though most likely that can be avoided with straps that allow some movement. Depending on the slope of the grade and the potential for frost heave, you may need a meter riser slip fitting. I'm not impressed with that Milbank equipment. Siemens/Murray make some nice meter mains with a separate pull compartment to the left of the breaker compartment. Finally, your rods will have greater efficiency if they are further apart. 6 feet is the code minimum. 16 feet would be better. I think you want to do some research with the local utility and building department before proceding. Good luck.

Am I seeing this correctly that another pipe enters from the background of the picture, and that there is no vertical vent pipe at the sanitary tee that is just downstream of the wye with the shower trap arm? Regardless, this thing is a mess. If that pipe to the right is the vent, then the problem with having it "flat vented" is that water in the shower arm can close off the vent, siphoning the shower trap. Anything that causes you to lose a trap seal can allow entry of sewer gases, vermin, and other nasties into the living space. If that pipe to the right is a fixture drain with a vent on top of it, then you conceivably have an instance of horizontal wet venting, which California started to allow in bathrooms in 2008, except that it is still fubar. The wet vent would need to be sized for all the fixtures for which it is providing venting, and it doesn't seem possible here. The sanitary tee also has to be vertical. What is the other pipe coming in through the combo fitting in the foreground? It also looks like they notched the bottom of the beam. A sort of general rule to follow on something like this is that plumbers will install pipes vertically or horizontally. They won't improvise something that is in between.

I've seen a few built-in vacuums that required a 30-amp / 120-volt circuit. Obviously a different situation than your 3-bedroom duplex.

Wouldn't that cause the service mast to act as a parallel conductor to the neutral? That seems like a bad idea. No? If not, then why the insulator? It would cause the service mast to act in parallel with the neutral. I don't see that as a bad idea. It would have current on it. It would have only barely measurable voltage. The NEC allows the neutral to be a bare (copper) conductor inside that service riser (230.41Exc.1). A bare neutral would also allow current on the service riser. We've already seen what happens in a fault situation with the bonding jumper missing. So, let's look at what happens in a no-fault situation: Suppose you have 2AWG aluminum service conductors and service drop conductors. To give us some measurable voltage on them, let's say the service drop is 100 feet back to the transformer, and that we have 10 feet of 2-inch steel conduit between the service equipment and the weatherhead. Next let's assume a really huge imbalanced load, like maybe 60 amps, which is more than you would ever see in real life. The voltage drop on the service conductors would be approximately 2 volts (60 amps times 0.0319 ohms). In the first 10 feet of that, the voltage drop would be 0.2 volts. That would be your maximum theoretical voltage potential between the service neutral and the mast at the top. In practice it would be much much less. There isn't a need to insulate it to try to maintain voltage potential between them. Again, I think the insulator is someone's idea of a mechanically more reliable connection. In the same vein, the service enclosure also carries a small amount of current, yet if everything is connected right it is safe for you to touch it. It and the grounding electrode conductor are in parallel with the service neutral. Jerry Simon has taken many pictures of his ammeter clamped around the grounding electrode conductor and showing fairly high amperages. Those grounding electrode conductors can show that kind of current while still having barely measurable voltage. Same story here at the weatherhead.

We've taken up birding as an age-appropriate hobby, and like Bill we are fascinated by raptors. One of our favorite movies is Winged Migration. Reading this convinced me to add it to the Netflix queue again.

Can you tell us why? It's never done that way in my area. The neutral must always be bonded to that mast. The place where you typically see that bonding connection is in the service equipment, and any additional bonding at the point of attachment should only be adding to what was already present. Using an insulator at the mast may provide a more reliable or durable connection from a mechanical standpoint, but not electrically. Suppose that inside the mast the insulation on a hot conductor is damaged and that it energizes the conduit. The path for current is from the conduit to the enclosure of the service equipment, across the main bonding jumper, and over to the incoming service neutral. There is no breaker in that circuit - it is on the "line" side of the service equipment. A fault as described here is going to cause something pretty bad - it could possibly cause a fire or blow up the utility transformer. If you were lucky it would trip the overcurrent protection on the primary of the transformer and just knock out power to all the customers served by it. Suppose we have the exact same thing, only this time there is no main bonding jumper in the service panel. Now nothing blows up. Instead, something much worse happens. The conduit sits there with 120-volts potential, waiting for you to touch it while also contacting a grounded surface. You become a human bonding jumper. If the service mast had been anchored with metal to metal contact instead of that insulator, we are back to plan "A" (a noticeable fire or explosion instead of a potential electrocution). The reason we require bonding jumpers around concentric knockouts on the line side of the service is to assure that we are using plan "A" rather than the human bonding jumper.

I'm not sure what you mean here. To "close" the main breaker is to turn it on, i.e., to close the contacts. To add to Mr. Kogel's point, when we write instructions on these things it is easy for us to use a vernacular that only makes sense to the person that wrote it, and which could mean the opposite to the next person to come along. Nothing takes the place of a transfer switch that breaks contact with one power source before making contact with the other power source. Even with that idea in place, I once ran across a house that had a subpanel that was supplied through an automatic transfer switch that allowed a unique problem. The homeowners were experiencing lots of failures of electronics. They had frequent utility outages and their generator was used a lot. After much effort, we eventually discovered that the hot wire of one circuit from the subpanel was also connected to a circuit from a panel that was supplied only by the utility. When the power would go out, that circuit was backfeeding half of the house off the generator. When the generator would come back on, the transfer switch waits for five minutes of proven uninterrupted utility power before handing it back to them. During those five minutes, half the house was receiving power from two independent out-of-synch 60-herz sources, resulting in electronic mayhem. Blocking diodes in the generator are supposed to prevent this, but they didn't. Some 30K later, we ended up putting the whole house on the generator on a new transfer switch.

I agree with Marc. Instead of creating a cord with suicide plugs on each end, buy a small Generac transfer switch and have it installed by an electrician. It is pretty simple. You place it next to your panel. A whip runs from the transfer switch panel to your existing panel. Inside the whip are wires for a half-dozen circuits. In your panel, the conductors to those circuits are intercepted and run to the transfer switch panel, and other conductors in that same whip make the connection back from the transfer switch to your breakers. The transfer switch plugs into your generator.

The SWD rating is an additional (and pretty meaningless) designation. It can also be used as a switch for other purposes, such as incandescent lighting. I think the idea is that an older magnetic-ballast fluorescent has a greater initial current surge, and the SWD rating means that UL has evaluated it for a certain number of such operations without degradation of the internal contacts.

What Jim said. Also - The markings in your first photo indicate that aluminum wire is acceptable. The "SWD" in the first photo means "switching device" meaning that the prototype of this breaker is also listed for use as a switch for fluorescent lighting.

A friend in North Carolina has a house in the woods in the smokies, and is finding what he thinks are subterranean termites in his garage (and in the firewood stacked outside it). I'm not familiar with bug issues in that part of the world. Are bait stations a good idea?