Hot answers tagged

92

The idea is to not rely on any single point of failure. For you to be planted six feet under, you want at least three things to have gone badly wrong at the same time. Your lockout padlock fell off. Someone didn't realise you were working on the circuit and switched the breaker back on. You forgot to turn off the isolator switch. You didn't notice the ...


70

Your grinder is a Class-II Double Insulated appliance and therefore does not require a ground/earth connection. But even if you did decide to fit a 3-pin plug, what would you connect the 3rd pin to? There's no 3rd wire in the cord, nor is there a ground point in the device to connect it to.


67

Absolutely not safe. Those trusses were engineered with a heavy (critical) dependency on the bottom chords, which are in tension. Removal has left them extremely vulnerable to collapse due to spreading, especially under snow loads, but also under just the load of the roof itself. The roof system is basically a hinge now. To get a good mental image, ...


66

A de-energized circuit is like an unloaded gun Once I worked on a circuit. I shut off the breaker (I knew the circuit well, since it powered the lighting in the electrical parts crib) and double checked power was off. As a a third check, I brushed the now-dead hot wire against EMT ground. Was expecting nothing or possibly a huge, sunburn-making arc flash....


64

Fire extinguishers (here in the US anyway) are REQUIRED to not be usable after being discharged, partial or not, because you can never know HOW MUCH extinguishing material was discharged by just looking at the pressure gauge. So the valves are designed with breakaway seals that, once broken, will not hold the charge for very long, forcing you to replace it ...


58

Yes. This is not only safe but best practice. Tuck the capped wires completely into the junction boxes to avoid accidentally snagging on passing ladders, wallboard, etc. If the room continues in general use then install blank cover plates.


56

DANGER!!! This sounds like a ground fault. They are particularly dangerous if you get wet, which is why Ground Fault Circuit Interrupters have been required for many years in kitchens and bathrooms, among other places. If you have shoes on, you are insulated from the floor. Without shoes, a little bit of electricity makes its way from the fan through you to ...


52

Test Tools In approximate descending order of safety (though the professional multimeter could arguably be higher if you are careful about how you use it) Voltage tester A professional electrician would very likely have one of these: If you expect to do occasional DIY electrical work in the rest of your life, you should consider buying something like ...


51

It's dangerous. You've spotted one important flaw but it can combine with others to make a really dangerous product. I originally suspected it was made in Europe by someone with more interest/knowledge in the sculptural aspect than the electrical one, but I've since spotted contact details in China for the seller. Either way it shouldn't be sold. Here's why ...


50

Use Screws Anyway If it was me, I would quietly ignore "I am not allowed to secure it using screws in the wall." We are talking about a couple of screws here, which would leave ~ 1/4" holes, not cutting out large sections of the wall. Assuming it is drywall or plaster over studs, as opposed to a brick wall, I would put in two screws (~ 2" ...


40

With the breaker off, put a wire nut on each wire separately (don't nut them all together!) and you're good to go. That is the proper way to terminate unused wires, whether the breaker is to be turned back on or not.


37

WARNING: This answer describes a fictional installation, and is NOT meant to be a solution to a problem. This setup should NEVER be implemented in the field, as it is unsafe, and violates countless codes. These codes are intentionally ignored in this answer, in an attempt to keep the answer short and to the point. There's likely no way to make this setup ...


35

Depends on the voltage you're working with. If you're working in a residential setting, simply turn off the power and wear any type of glove you find comfortable (including none). If working in an industrial setting, where turning the power off is not an option. You'll have to choose a glove system based on the voltage you'll be working with. A glove ...


33

If it's a dry chemical extinguisher (seems likely, most common, particularly with a pressure gauge) the simple answer is that the valve has got dry chemical dust in it and no longer seals properly as a result. When refilling the valve or valve parts will either be cleaned or replaced as needed, the dry chemicals will be placed in the container, the valve ...


31

With no bracing above, you might want to check the out side walls - they are probably already spreading. Once they start moving the stabilization and repair can cost many thousands if the roof stays in place, tens of thousands if it comes down. There are ways to mitigate the damage done, but it needs to be done now before the walls spread, the rafters ...


29

A diagram put out by the US Product Safety Comission shows that the left leg and left arm/hand are the most commonly parts of the body injured by chainsaws: (Source: OSHA Web site) If the dots on the diagram represent frequency of injury, protecting the left hand would help prevent a common source of injury. The State Compensation Insurance Fund website ...


27

Do not wear gloves while using a bandsaw (or any powered saw, drill press, or planer for that matter). The gloves will give you a false sense of security and do very little to protect your hands. In fact, they may end up getting your fingers pulled into the blade if the material catches. Which would you prefer: a cut fingertip, or a mangled hand? The best ...


27

I'm not certain what guage that wire is but many manufacturers will cite a minimum bend radius. It may or may not be code compliance wherever you are in the world. I suspect that wire has a minimum bend radius between 1 and 2 inches. You can achieve that most easily by just rotating the receptacle. The wire will tail upwards, which will look strange, but it ...


26

Almost all of the Home Depots that I do business with have short term rental trucks available right in their parking lots for very reasonable rates. Call in and reserve one for a particular time. Drive to the Home Depot in your car and park it in the lot. Go inside and checkout the truck. Then drive it up and load all of your materials and head home with it ...


25

Like Captain Kirk said when he sensed a trap, "It's never a bad time for a battle-stations drill". It's never a bad time to go through and thoroughly inspect your Grounding Electrode System to assure it's in good order. You may have gotten blindsided by something like the water company severing your water pipe ground by inserting a plastic smart meter.


25

I do a lot of work on older homes and see stuff like this all the time. Keep in mind that the equipment grounding conductor (EGC), that bare safety ground, was not always present in wiring systems. If you see old homes - a little older than this one - with two-prong receptacles, those were wired back before the EGC was part of the system. I think when ...


25

The safety solution is to either add a grounding using a grounded cord with the ground branching off and attaching to the metal as close to where it enters as possible. Or you can convert the lamp to low voltage LED with the 220 to 5 or 12V conversion external to it so safety ground isn't a requirement.


24

Yes, there is a risk. Even a properly installed and protected electrical system can fail to protect you, either because of unforeseen situations or component failure. There are two types of flaps. One is watertight only when not in use and closed. This is probably what you have. This type of outlet is only meant to be used temporarily when exposure to ...


24

An underwater GFCI doesn't matter That is to say, it doesn't perform any useful function underwater. It does nothing to prevent the water from being electrified, which is its one job. Here's how a GFCI is laid out. As you can see, if water can get to the "Line" side of the device, then it electrifies the water. And the GFCI cannot do a thing about it. ...


23

Sounds like a fire waiting to happen. You'll need to cut out the damaged part and splice them together again. If there isn't enough slack then you'll need a new short run of wire to bridge the gap. Because you have physical access to the area The splices should be inside junction boxes. Bill the work/materials to the plumber or deduct it from his bill if ...


22

You didn't mention how you're using the ratchet straps, but from your concern about slipping, I think it's possible that you could be using them to better advantage. So I apologize if this is what you're already planning to do, but just on the off chance it isn't... For the MDF, you want the straps going over the edge of the MDF and running straight down to ...


22

It likely has to do with the lifetime of the hardware itself. Remember, there's a circuit board and a light source, as well as a detector. Those don't last forever. So the manufacturer certifies the device will work for only 10 years, and then (in some modern units) sets a hard sunset by using an unreplacable battery. In some regards, this solves the ...


21

Not only will you need to get your local inspector's approval, in writing (and the inspector will defer to Underwriter's Laboratories or other NRTL, so we're talking about getting a UL listing for your one-off) ... ... But all your thermostat wiring must now be re-done in Class I wiring methods Because you are intermixing thermostat control power with ...


21

While not strictly speaking "single use", I would consider a typical consumer-grade residential fire extinguisher (I have 2 - one on each floor, with the upstairs one near the kitchen) to be a single-use item. This is for a few reasons: Even a moderately sized fire could make good use of the entire extinguisher, so if it is "half used" it is already in the ...


21

It doesn't need to be a GFCI outlet. It needs to be GFCI protected. GFCI protection is conferred by having any particular outlet obtain power power from the LOAD side of a GFCI device somewhere. On most string-topology circuits, a single well-placed GFCI device will protect the whole circuit. If you stick a GFCI tester in there, push the button and the ...


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