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Douglas Hansen

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About Douglas Hansen

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  1. Version 1.0.0

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    This article focuses on the controversy over inspecting and reporting Federal Pacific panels. It has been published in the magazine for the California Real Estate Inspection Association and in other technical journals. By Douglas Hansen
  2. New Zealand has the right idea about cats. My sister's dog once went crazy barking at the back fence, jumping up along it, running back and forth to the door to get her attention. My sister finally goes around the block to the house behind her, and the elderly woman there has fallen down and couldn't get up. The dog knew. If my sister didn't have a dog, and that elderly woman had a cat, the cat would have waited until she died and then eaten her.
  3. There are limits to what one can learn from a strictly visual inspection of a pool. To really know if everything is working properly requires operating the pumps, timers, heaters, etc. I once did a home inspection where the pool equipment house had dried blood and brains all over the place. The pool inspector made a fatal error in the settings of his valves as he attempted to test the backwash, resulting in a pressure buildup and subsequent explosion that drove the valve piston through his face. I saw that as a reinforcement of my decision to limit my pool inspections and exclude operation
  4. In our jurisdiction, the architect or contractor files all the paperwork, and included in that will be a form signed by the owner stating that the contractor has their authorization. I am not surprised by the zoning violations that are also mentioned in the article. An area of single family homes is going to be overwhelmed by the number of vehicles and transient residents (secret service agents) using the property.
  5. With cable systems you can re-identify white wires to be used as ungrounded (hot) conductors. Aside from panels, this happens all the time with switch legs. With conduit systems you must pull the correct color if it is #6 or smaller. Black conductors #4 or larger in conduit can be taped at their ends to show that they are neutrals. Since your friend is primarily a commercial electrician, he doesn't use cable systems and it isn't surprising for him to be unfamiliar with these rules. They can be found in 200.6 and 200.7 of the NEC.
  6. The UL standard for AFCIs now includes testing with GFCIs in the circuit. In first generation AFCIs, GFCIs did cause nuisance tripping in some brands. These problems have been resolved. There are also dual function AFCI-GFCI breakers for most brands now.
  7. In our part of the world, NFPA codes and ICC codes work together fairly well. I haven't ever seen a non-federal jurisdiction use NFPA's life safety code in lieu of the ICC material that covers that subject. The only NFPA code that California directly adopts is the National Electrical Code. Some of the other NFPA codes and standards are adopted through their reference in an ICC code, and other NFPA codes might be used for guidance in gray areas (particularly mechanical design). The IAPMO codes make up the third leg of the tripod, and these can be a problem. There are many ways in which the
  8. Royal Institute of Chartered Surveyors http://www.rics.org/us/
  9. This generalization might be a bit broad. The NEC requires a listing on some, not all, components of an electrical system. For instance, metallic wireways and auxiliary gutters don't require listing, whereas nonmetallic gutters and wireways do require listing. Motors don't have a UL listing, and luminaires weren't required to be listed until the 2008 edition of the NEC. To the topic at hand here, I once saw a Murray panel that had a specific list of the breaker model numbers that were acceptable in that panel. The contractor had a Murray breaker that was not on that list, and a close exam
  10. A friend is remodeling his pool house to turn it into an art studio for his wife. It is in the smoky mountains, near the North Carolina / South Carolina border. It's a simple gable roof structure with no attic space. The rafters are 2X10s and there will be 6 inches of insulation in the rafter bays. The climate includes some freezing and snowfall, and in the summer months is hot and humid. Heating and cooling of the space will be from a ductless mini-split, and realistically there will be long periods of time in both winter and summer when it won't be turned on at all. Should he insta
  11. If the motive for replacing the panel is to have something that is accepting of AFCIs, you wouldn't want to choose a Square D product. They don't make a 2-pole AFCI, so they aren't compatible with multiwire circuits, which almost every house contains. Because Square D doesn't make a breaker that will work with them, they advise against using multiwire circuits, as seen on pages 4 & 5 of this document. I have no doubt they would sing a different tune if they did make a breaker compatible with multiwire circuits, such as those made by Siemens and Eaton.
  12. Thanks, Marc, I should have said shocked or burned. IMO, the Inspectapedia comment is not incorrect. He says there that if an arc jumps to a person, the AFCI will detect that arc and we assume it will then trip - shock prevention, no? I have no idea why the Canadian authorities chose bedroom circuits only for AFCI protection, but I imagine they have studied historical events to make their decisions. The idea that an AFCI detects an arc to a person is nonsense. First off, the detection mechanism of an AFCI is that it looks for a repeating pattern of voltage drop and current spikes that a
  13. The intent of bonding CSST is protection from damage against indirect lightning strikes, not a direct hit. The idea is that if the earth on which a building sits has an elevated voltage from a nearby lightning strike, the voltage potential of the metal in the building will be elevated equally if all that metal is bonded together. That in turn lessens the chance of an arc between metals having differing potentials. The bonding requirement for CSST, with its mandate for a #6 conductor, is only found in plumbing and mechanical codes, such as NFPA 54, the UMC, UPC, etc., and not in the electri
  14. The code-prescribed sequence of inspections here during new construction is that gas pipe is inspected visually prior to concealment, and pressure tested after concealment. If the plumber wants a pressure test at both inspections, that's fine, but only the one after concealment is required. The reason it can't be done prior to that is that you want to wait until all the nail guns have been put away before finding out if that pipe has a leak. This applies to black pipe, galvy, and CSST. Douglas Hansen www.codecheck.com
  15. I think Jim is referring to the common range hood / microwave combination that is allowed to be cord & plug connected if on an individual circuit per 422.16(B)(4). In high-end kitchens we don't see these as often as the independent hard-wired range hood. Marc has convinced me with the comment about how some of these indoor units include resistance heat. We have concluded that the best way to achieve consistency within our department is to always require a local disconnect. This will comply with our mechanical code as well as the broadest interpretation of 440.14. Thanks all
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