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1

It's pretty much the same logic that always, under any circumstances, forbids you to cross a road on a red light. Obviously, if you understand how the traffic is organized and carefully look for incoming cars before crossing, nothing bad will happen. However, if you get a habit of breaking the rules, there will be a risk. The same will happen with extension ...


1

One more important reason: Coiled cable. Because your extension cord is 20 feet and you only need 5, so why not roll the rest into neat circle? Don't. Coiled cable will heat up rapidly with no way to dissipate the energy. Good quality extension cords will have a current rating "when unrolled" and "when coiled" - the second one will be ...


3

One thing that is not explicitly mentioned here is something that used to happen to me when welding at a client site. - we have long extension cables (heavy duty) which easily run the welders. if, when the length is not needed, we leave them wound-up the customer experiences their earth leakage tripping more often, and the cables get much hotter ( to the ...


5

You're fine -- having neutral in one of the switch boxes is sufficient While the text of NEC 404.2(C) isn't the clearest on this, in most multi-way switching situations, you can get away with only having neutral available at one switch box. This is because 3-way smart switches either use a mechanical remote switch that only needs a couple of wires run to it,...


12

That is a 240V breaker, not two singles handle-tied. You can tell by the labeling. They didn't bother labeling the other half. Use of a 240V breaker is a perfectly legitimate substitute for a handle-tie. One good reason The usual reason to handle-tie two independent circuits is they both land on the same yoke. (A yoke is the frame of a switch or receptacle)....


4

In addition to other good answers, often there usually isn't a perfect zero-resistance connection where the plug fits and holds in the socket purely by friction. If one is using an appliance with a high current draw for a period of time, if any part of the connection gets warm/hot/overheated before the wires themselves, typically its where it plugs into the ...


6

Because of the way the book flows its discussion. You're showing us their second "alternate" scenario. Their first "primary" scenario is a Multi-Wire Branch Circuit (MWBC) in which the individual GFCIs would be required due to the shared neutral. It is showing this as an alteration of that design. They didn't want to introduce 2 new ...


1

It's a book that was clearly not written by a lifelong electrician or contractor. No contractor would ever make such an installation, simply for cost reasons. There is absolutely no measurable benefit to doing so.


3

Yeah it looks ugly. Definitely not a professional installation, but there doesn't seem to be a code violation or hazard based on your pictures. If it was done recently, then it's not to code because the installer put in a NEMA 10-30R receptacle (3-prong) instead of the required modern NEMA 14-30R (4-prong). You can simply leave it as is and use it. Just make ...


1

Connect the fixture hot to white/black instead of black/black What you have here is an old-school switch loop connection that's also feeding switched-hot onward to another set of fixtures. When you initially hooked the fixture up, you connected the fixture's hot to the junction of the two black wires, which is where the incoming always-hot connects to the ...


3

Yeah they appear to be separate Romex cables with their own neutral from the picture. It's likely they whoever made the installation had a 2 pole 20 amp on hand and used it in a pinch. There's nothing wrong with it other than the inconvenience of having to shut off two circuits for maintenance.


7

Quite simply, it's the law in most states as around 40 states have adopted the international fire code. The International Code Council (ICC) covers space heaters under the International Fire Code, Section 605.10.1-4. The code lists under what occupancies space heaters can be used, it specifies that only listed and labeled portable space heaters can be used, ...


4

What the book suggests is overkill. What you said is commonly done: Line in to the GFCI and load to the downstream outlets. You are supposed to put a little sticker on the downstream outlets saying they are GFCI protected, but that's often overlooked. Yeah, a tripped GFCI would kill power to the downstream outlets, but so what? Just reset it. Just don't ...


9

Lawyers, pure and simple. When you start a fire with an electric heater plugged into an exension cord, even if the extension cord is massively over-adequate and properly protected from damage, you were "violating manufacturer's instructions" and they are off the hook, legally, even if the fire had nothing to do with the extension cord. It's "...


4

The common failure mode I am familiar with is plugging two (or sometimes even more) heating appliances in the extension cord sockets. The problem is, breakers don't react quickly to mild (e.g. 2x or 4x) overloads. This is both a technology limitation of the traditional fuses and an engineered feature of the newer electronic protection devices - in order to ...


25

Well, you really nailed it. It's the fact that normal everyday garden variety extension cords are usually 16 AWG, or maybe 14 AWG if you're lucky. The reality is, an extension cord, properly sized for the load, would pose no safety issue, other then potentially being damaged from grandma's proverbial rocking chair, but then again, we have AFCI breakers to ...


17

In addition to the already stated "shouldn't use a flimsy little 18 gauge extension cord", which would have a definite overheating problem, two specifics come to mind: Tripping Tripping over an extension cord is a real problem. Tripping over a cord that then moves a hot appliance into a dangerous position (on clothes or curtains etc.) is far ...


0

It was very common practice back in the day to use ceiling boxes as junction boxes for entire circuits. All the black wires should remain connected together as they are different branches going to different receptacles and switches. One of those black wires goes down the cable with the red wire to feed a switch. The red wire is the switch leg coming back. So ...


2

You can make the 3 wire cable work but you won't have the ability to control the fan manually. Step 1: remove the control module and connect the two cables together like this: 3 wire cable > 5 wire cable Red > red White > white Green > Brown You won't use any of the other wires in the 5 wire cable. Now for the thermostat, connect: Red > R ...


3

As far as GFCI requirements in a bathroom all bathroom receptacles have been required to be GFCI protected for many cycles NEC 210.8.A.1. currently AFCI’s are not required in bathrooms and I would suggest not getting a dual function device as AFCI technology is still not mature and there are problems, since my last job change I won’t be wiring homes anymore ...


2

There are no pros for using a GFCI breaker. It's stupid, IMHO, to combine functions into a single point of failure, thus having to replace a much more expensive device. Another con is that you have to travel a much longer distance to the centrally located panel to reset the GFCI should it trip. Around here, a typical GFCI breaker costs about $60, and a GFCI ...


1

The hub and spoke topology not only is not prohibited by Code, but may be a more electrically sound design. Fewer points of failure and shorter overall runs of cable. It does, however, introduce a single point of failure and eliminate some redundancy, so it's a give and take situation. Luckily, all hardwired smoke detectors come with a 9v battery backup and ...


1

For typical interconnected smoke alarms, this is fine For the typical hardwired interconnections found on North American smoke alarms, this is alright -- they don't care about the topology of the wiring, only that the interconnect wire connects the smoke detectors together.


4

Mice is how it happen. Mice have been chewing on the wire. You got mice. Can tape for now, but should replace cord as soon as possible. The large section seems like the wire(copper) has also been chewed. Less copper can mean the wire could heat up more. The two prong adapter is only good if the box the outlet is in, is grounded. The adapter works if a ...


1

If the equipment that you are dealing with is marginally sized and you are worrying about exceeding the capacity of the existing system do as @Gil stated and add a "heat recovery system"to the fresh air intake to capture as much of the cooling capacity as possible. And, instead of an always open pipe you could add a barometric damper which when ...


0

You can build an OR gate by simply wiring switches (relays) in parallel: if switch 1 is closed, or switch 2 is closed, or switch N is closed.. then power flows through any one (or more) of them to the load. What to use for the switch? Well, it depends on what you want to sense. You could sense air flow as proposed by DrSparks. An alternative is to simply ...


2

It sounds like you know a little about logic. The problem you posed would best be solved using a small PLC, commonly referred to as a smart relay. I have used Zelio in the past and had fantastic results. Smart relays are very easy to setup and program. Zelio, in particular, has a visual design app to simplify programming. They come with a number of different ...


1

Sure you can. It ought to work fine. A switch is a switch no matter where you put it.


1

Absolutely. According to Sherlock Holmes, if you've eliminated all the other options, what's left is it. You can make future-you grateful by doing the replacement a bit better. Install CAT6 this time - it is close enough to the same price, and in another 15 years CAT5 will be extra-outdated like CAT3 is nowdays. I might consider Fibre (fiber) cable but ...


0

You have many possible solutions. When I moved into my current home we were having negative air pressure problems because of the fans etc. I installed a fresh air makeup vent as my solution. I live in the northern climate and it has not caused any problems in sub zero weather. A fresh air vent It is a vent open to the outside (protected so nothing unwanted ...


0

FWIW, I once bought a GE Circline fluorescent bulb, and it lasted only 6 months. I got a replacement, and that lasted only about 6 months. They were just two defective bulbs, by chance. That might have also been about 10 years ago, same was with this OP -- maybe there were bad batches.


0

You'll have to pull the wires back through the LB to install a new conduit body. There's a product by Arlington Industries called ANYBody. It's a conduit body with removable hubs that allows you to create any configuration required. Also, here's a link to Arlington's website for that product. You can enter your zip code and find a local supplier. Most ...


2

I'm pretty sure the problem is the cable but can't prove it. Order a run of Cat5e that's the same length and temporarily substitute it for the possibly faulty cable (as in, lay it wherever it needs to go to get between the two points - through windows, down the side of the house, just lying on the ground, etc.). Not free, but also not expensive (depending ...


0

Any switch that is more than a simple mechanical switch: Timer Dimmer Smart Switch (e.g., WiFi, programmable, remote control, etc.) Motion Detector needs to get some power for its own guts, in addition to power for the lights (or other devices) that it controls. (Actually, basic dimmers don't necessarily need power, but more advanced models often do.) ...


4

It's not "OK" in that it's not a code compliant installation. Having a proper 4-wire connection is good, but other things are not. It appears to be missing a clamp at the entrance to the box, as well as the exposed cable. Laundry closet should be an easy bit of drywall patching to put it in the wall (does not have to look great as no one will see ...


0

Of course it can. Cheap testers and stuff like that tend to be glitchy and have inaccurate readings. I recommend that you get new line; the cheap way to to it is to get a ethernet cable kit like this one, https://www.amazon.com/dp/B01L924436 and some CAT6 cable at a local hardware store, and do it yourself.


-5

Use the neutral as a switch leg and the ground as your new neutral and be done with it!!! The white will switch the fan and the black will switch the light, get a stack switch from the hardware store... power into switch and the white/ black go up to fan white to light black to fan done deal! Just make sure to wrap the bare ground with white tape and ...


16

This is where better networking gear would come in handy. This answer will likely not help you in the slightest right now. It's just something to think about next time you need to buy some networking gear. There are many ways a cable can go bad without compromising DC continuity. We're talking about a highly optimized transmission line for signals with a ...


2

If this was new construction and an inspector saw this, he's make you pull new wire. Since it's existing, wire nut some extra wire onto the short piece so you have room to work with the switch. Never, ever cut wire in a junction box. you never know when you might need it.


1

I'm going to ignore the information about wiring, because any answer about wiring will change depending on what switch system you go with. In a "light controlled from 3 switches" circuit (known as 4-way) you have two 3-way switches and one 4-way switch. The 4 way switch has 4 wires, and the 3 way switches have 3 wires (not including grounds). The ...


10

The only layman's test of an ethernet cable is whether it delivers desired data speeds in practice when installed. There are many levels on which it may fail. Continuity is level 0, the most blunt and easiest to detect. You can detect it with a continuity tester, or even with your eyes if, say, the cable has been cut in half. But if it passes that test,...


30

Yes, absolutely. However, if it was working (at high speed) previously, then stopped, that is a little strange, but not unheard of either. If the cable is old and has been run over by office chairs or what have you, it very well may have developed cracks in the copper that cause intermittent disconnections when the cable is nudged one way or another. If the ...


3

The contactor is probably stuck closed. You should shut the breaker off immediately to prevent a fire. There's a high limit switch but that won't do any good if the contactor is mechanically stuck closed.


2

Let's review how 3-ways work. Note the 2 travelers: one is hot, and one is not. They must necessarily always be in the same cable, and be the same on both ends. That uses up all the brass screws and leaving only 1 screw left per switch. Once you get the travelers right, there are precious few wires left. Hooking up the remaining wires is fairly obvious. ...


0

Try testing each switch to make sure you have assigned the correct wires to the correct screws. Disconnect all wires (mark them so you know which was connected where!) and then use a voltmeter in "ohms" mode as follows. Connect the probes to any 2 screws. If flipping the switch causes the resistance to go from zero to Infinite, then you have ...


10

Yes, I see several problems. Wire just stuck under a screw, and not using a proper shepherd's hook with a more than 180 degree bend (i.e. squeezing it together after forming it. Watch a Youtube video on how to put a wire on a screw. Insulation excessively stripped, leaving bare bits of wire sticking out beyond the back surface of the switch. Not OK. ...


4

Yes it can and it is the best way to do it. Those holes in the back are commonly called backstabs and have a long history of failing. After you turn off the power, you can remove those wires by sticking a small screwdriver into the slot next to each hole and pulling the wire. You can also hold the wire and twist the switch back and forth while pulling the ...


19

Using the hole(s) in the back is called a "back stab", and, while technically code-legal, they're frowned upon because they can come loose and cause arcing and, if left alone long enough, fires. The side screws are actually the preferred method and are applicable for either 12 or 14 gauge wire. However, the way you've done it is missing on 2 points:...


0

In theory, yes you could reduce the size of the neutral conductor. It is probably only used to supply 120v to the computer power supply. Why it couldn't be derived from the 240v source? Your guess is as good as mine. The problem with doing this is, if you're installing a plug, like a NEMA 14-50, there is no control of what kind of device could be plugged ...


2

A few points First, EVs don't use neutral. The J1772 connector doesn't even have a neutral pin... and there's not much inside an EVSE, so it doesn't need neutral (unless they really chintzed out on the internal GFCI, in which case, don't buy that one). So neutral wire goes away. Second, you may be able to run better wire insulation that allows higher ...


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