craighaggart

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About craighaggart

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    Sunnyvale, California
  1. That means your tub doesn't use 120V for anything (ozonator, lamp, whatever), which is what you'd need the neutral wire for. I suspect that not many tubs are like that, but for those that are I would recommend using one red wire and one black wire instead of two of the same. It will make it easier if any repairs or modifications ever need to be done. I've had to trace unmarked wiring before, and I spent a significant amount of time thinking of ways to torture the person who put it in. Craig Sunnyvale, California
  2. Stranded THHN/W copper is not only OK, it's probably the only wire you'll be able to find in 6 AWG at most retail outlets. Solid wire is not only unnecessary, it's much more difficult to work with. Try pulling 4 hefty conductors through a conduit with a couple of 90-degree bends! Oh, and I'll share my mantra with you: conduit is cheap. Use the largest conduit you can reasonably work with. You will not believe how much easier it is to pull wire through larger tubes and junctions. The price difference between 1" RNC and 1.5" RNC is trivial. The fittings cost more, but again they're chump change in the context of your whole spa project. Craig Sunnyvale, California
  3. Your 310 kWh in 29 days represents slightly less than half a kilowatt per hour over that period, which is the energy necessary to compensate for a temperature drop of a bit under 1/2 degree per hour in a 400-gallon spa. Seems like a reasonable ballpark figure to me. (Back-of-the-envelope math: 400 gallons of water is about 3,300 pounds. It takes one BTU to heat a pound of water one degree F, and a kilowatt-hour is roughly equivalent to 3,400 BTU. Therefore it takes a tad under one kilowatt-hour of energy to raise the temperature one degree in a 400-gallon tub. 29 days = 696 hours. 310 divided by 696 = 0.45 kilowatts every hour, 24 hours per day, for 29 days, on average.) The actual energy usage to keep your spa hot depends on the insulation of the tub, the insulation of the cover, and the temperature difference between the spa water and the surrounding heat sink (outside air). The heater will come on much less often in the summer. Craig Sunnyvale, California
  4. This is totally do-able. The old spa circuit is 240V, which is why there are two hot wires (L1 and L2), each protected by a 40A breaker. Each 240V leg is 120V to neutral. You can wire up a new little 120V subpanel at the gazebo using either leg and a 15A or 20A breaker. You could also wire up two new branch circuits, one with L1 to neutral and the other with L2 to neutral. But you probably only want one, so use the black wire (L1) and cap off the red wire. In fact, I'd remove the 40A breaker that feeds the red wire and put a blanking plate over the opening, and then label everything at both ends so that anyone coming along after me could easily figure out what's what. You didn't say whether or not the gazebo light would be a corded unit; if so, use a GFCI outdoor "in use" outlet (one that remains weatherproof when something's plugged in). You could also do the conversion at the existing 240V spa box, but working just at the downstream end has the advantage of keeping the possibility of once again hooking up a 240V spa in the future if your aunt changes her mind or sells the house or whatever. Plus it doesn't really save you any work, and a true conversion would mean pulling the red wire out of the conduit. Remember, ALWAYS SHUT OFF THE POWER FEEDING ANY CIRCUIT YOU PLAN TO WORK ON, AND ALWAYS VERIFY THAT THE POWER IS ACTUALLY OFF! No joke; this stuff will kill you. Hope this helps! Craig Sunnyvale, California
  5. Ah, yes, PMS: Production of Motor Spuriosity ! Craig Sunnyvale, California
  6. Chip, your proposed spa hookup is nearly identical in every way to mine. I have individual #6 copper wires running from dual 50A breakers at the service entrance panel to a Connecticut Electric GFCI spa disconnect (required by code), which is mounted on the back corner of my house within clear sight of the spa (required by code). From there the #6 runs through buried 1.25" nonmetallic conduit to the spa. The total wire run is about 65 feet, and there are no splices. The only break is at the GFCI panel. My system has been in continuous use for two years now. I've had no problems of any type, and no nuisance trips. Craig Sunnyvale, California
  7. I'd say the people who made those mistakes didn't understand why things are done a certain way and made no attempt to learn before doing the work. If the above stuff is what you always see then I suppose it's understandable that you assume the worst, but I assure you that many normal homeowners are capable of doing safe electrical wiring. You just don't see their work because you have no reason to -- and crappy work is naturally what gets noticed. Craig Sunnyvale, California
  8. Would you please post the specifics about these clearly unsafe wiring situations? It's possible that I (and others) might make some of the same mistakes without realizing it. I for one am always interested in learning. Thanks! Craig Sunnyvale, California
  9. The code is the size of a Manhattan telephone book. It's pretty much guaranteed that someone can find fault with SOMETHING that was done by a layperson, but that doesn't necessarily mean it's unsafe or problematic. I maintain that wiring a home spa is something that can be done safely even by people who don't get paid to do it. But then again, I'm clearly an outlaw. I also <gasp!> work on my own car! Craig Sunnyvale, California
  10. Well, my installation probably isn't much longer of a run than yours will be, and I happily went with #6. For me, the breakpoint involves balancing the cost, the potential for problems, and the tolerance of the load. THHN/THHW in a big conduit doesn't present a heat issue, and spa pumps aren't likely to have a problem with a 2% reduction in supply voltage. The cost difference between #6 and #4 is not insignificant, plus #4 is much harder to pull. These issues were in my mind when I did my installation, and I decided to use #6. I pay a lot more attention to voltage drop in low-voltage high-current circuits, such as in boats and RVs. Rule of thumb for me is in the 2% region, but again it's an ad hoc deal. Cost is also a consideration. If being slightly more conservative costs only a tad more, I often go for it. But if it's a lot more expensive -- as well as a much bigger hassle -- to go with bigger wire in a situation that doesn't seem to justify it, I'm OK with smaller/cheaper. I'm sure you'll be fine, Chip. Get that spa hooked up and enjoy the soak! Oh, and if intellectual curiosity is problematic, I'm doomed. Craig Sunnyvale, California
  11. Chip, I just re-read the post where you mentioned the wire run and realized I mistakenly read "50 feet" rather than 150. If that's truly the one-way run you'll be putting in, the drop with #6 is actually about 6 volts at breaker capacity -- although you won't ever actually draw that much current in use, because of course it would trip the breaker. If you're worried about it and you can fit #4, that size drops 3.8V at full breaker current. But is your one-way run really that far? Maybe I'm just used to the small suburban lots around here; at my house, you'd need to run a wire diagonally all the way from the very front corner of the lot to the opposite back corner to get 150 feet! Craig Sunnyvale, California
  12. You can use an online calculator if you're really concerned. The one at http://www.powerstream.com/Wire_Size.htm says a 50-foot run (100 feet round trip) of #6 copper wire at 240V, loaded to breaker capacity (50 amps) drops about 2 volts. It won't be a problem. Craig Sunnyvale, California
  13. I'm with you, Chip. Many people manage to make it through life without hiring experts for everything, and home wiring isn't rocket science. My apologies to journeyman electricians out there, but you know it's true. I operate a subatomic particle accelerator for a living and I can tell you that it's not rocket science, either. Like home wiring, anyone can do it if he/she is of average intelligence and has the interest in learning why things are done a certain way. As to spa wiring being "complicated" (as one responder stated), I respectfully disagree. It's actually pretty straightforward, and wire type and insulation type is basically constrained by what you can buy at Home Depot or Lowe's or whatever. You'll find that they all carry pretty much the same thing, and it meets or exceeds the NEC requirements for everything you'd do at a residential installation. Chances are, if you hired a local electrician, he or she would use exactly the same thing you're going to buy. Spa manufacturers typically suggest using #6 wire without mentioning distance probably because most home spa installations involve wire runs of no more than several tens of feet, which will not result in unacceptable voltage drop. The primary concern with wire size is ampacity. If you use 50A service for your spa and you have a continuous run, #6 will be fine in that regard. If you can go up a size to #4 you will see slightly higher voltage at the spa, especially if the run is particularly long. However, pulling wire gets to be substantially more difficult as the size goes up. I don't have the NEC tables in front of me but I did when I wired my spa two years ago and I chose #6. The large wire at Home Depot is dual-rated THHN/THHW, which is exactly what you want anyway. If you use "Romex" (sheathed conductors), you will probably need to go up a size because sheathed wires must be de-rated compared to individual conductors. One recommendation I can make from experience is to always use the absolute largest conduit that you can reasonably accomodate. The difference between a totally simple, almost fun installation and a dirty, sweaty, frustrating, knuckle-busting installation is in the wire pull. Larger conduit not only makes it a snap, you will also be using larger pull boxes -- and that's where the REAL difference lies. Fill tables in the NEC are not about conductor temps or anything like that; they're all about being able to pull the wires. Unless you have reason to use conduit sized to the fill tables, ALWAYS go larger! I used 1-1/4" (which is oversize) but would have been happier using 1-1/2". My mantra now: CONDUIT IS CHEAP. The cost of PVC conduit is trivial, and although the pull boxes cost more in larger sizes, it's still in the noise compared to the whole project (and you probably only need a few anyway). You can always use adapters to size large stuff down to match existing panel openings if necessary. Good luck, and report back when your spa hookup is done! I suspect you won't have any insurmountable obstacles.
  14. It doesn't really matter how you braid the wires together or attach them to the fish tape, you simply want to make it possible to pull them all through the conduit together without overstressing any individual wire. The standard way is to strip back several inches of all of your wires, then twist all of the stripped ends together, then stick the twisted ends through the eye of the fish tape, then bend the twisted wires back on themselves, then tape up the whole shebang so that it doesn't come apart when you're pulling. (Don't forget to run the fish tape through the conduit FIRST!) If the fish tape loop is too small to fit the 4 twisted wires through, use an intermediate piece of scrap wire or something similar -- and make sure you tape it, too, so it doesn't pull apart. It doesn't matter which end you fish the wires from, but if you have a tighter bend or series of bends at one end of the conduit, I'd pull from that end because you want the least resistance at the end opposite the one you're pulling from. Another factor is that it can be easier to run wires if there's room to lay them out to their full length (to help avoid the kinks that result from the fact that wire comes on rolls). So if you have room to lay out the wires at one end but not the other, that might help you decide which end to pull from. One more thing: Conduit is cheap, and using a larger size than required by code usually makes it much easier to pull wires through. Craig Haggart Sunnyvale, California
  15. This is probably too late for you, since it's Wednesday evening now, but just in case: My spa is a bit smaller (Artesian Ruby, about 325 gallons), but it also has a smaller heater than yours (mine is 4kW). I've drained and refilled it a number of times and can say pretty definitely that it takes an hour to raise the water temp about 4 or 5 degrees, or a total of about 9 hours from a cold fill to a nice, relaxing 103 F. Craig Haggart Sunnyvale, California