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SoundMonkey posted:that said, do not make a habit out of breathing the result of heating mineral oil. there's a reason nobody uses cracked-oil foggers any more and why the people who came up with the modern day fluid recipe got an oscar for it. I actually didn't know this, but fortunately I don't huff it so I think I'll be okay. I'll make sure I'm wearing my safety squints.
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# ? Jul 9, 2017 01:15 |
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# ? May 25, 2024 10:26 |
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Motronic posted:I actually didn't know this, but fortunately I don't huff it so I think I'll be okay. oh yeah this is more for people exposed to it occupationally ie actors and technicians
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# ? Jul 9, 2017 03:16 |
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SoundMonkey posted:oh yeah this is more for people exposed to it occupationally ie actors and technicians Still better than the old "use a match to find leaking Freon" trick
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# ? Jul 9, 2017 22:08 |
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Hubis posted:Still better than the old "use a match to find leaking Freon" trick What's the trick? Smelling for phosgene?
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# ? Jul 10, 2017 02:54 |
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Blackbeer posted:What's the trick? Smelling for phosgene? Yes (Watching the match as you go along the line -- if it flares up you know you've found a leak. A problematic approach for the stated reason.)
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# ? Jul 10, 2017 03:40 |
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Freon is non-flammable though.
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# ? Jul 10, 2017 13:53 |
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Blackbeer posted:Freon is non-flammable though. Upon reading, I think I had it backwards - you watch for the match to fade / go out (oxygen displacement by the refrigerant). I was thinking Phosgene was a combustion product, but it's just produced when Freons are heated. E: Anyways, IANA-HVAC-guy so this might all just be urban legend, since it's pretty much exactly what you shouldn't do around Freon. Trying to remember the original source I read about it in. Hubis fucked around with this message at 14:17 on Jul 10, 2017 |
# ? Jul 10, 2017 14:13 |
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Back in the day they used flame tests to detect the presence of chlorine. The flame would change color in its presence so it's useful to check for contamination from older refrigerants in, say, a recovery bottle, but it might have been used to leak test using the color of the flame. Older, now dis-used CFCs readily decompose in flame into phosgene (COCl2) but as I understand it HCFCs/HFCs that replaced a lot of those produce less/no phosgene but other slightly less toxic chemicals like carbonyl fluoride (COF2) and HCl instead.
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# ? Jul 10, 2017 14:46 |
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^^^^^Thanks, learn something new everyday. I feel for the people who worked on ac prior to freon. I asked dad while I was helping install an ac condenser today, and he said that when he started he used a halide torch (on freon, which has chlorine in it).https://www.youtube.com/watch?v=nFXSt-krDZA I think there's a copper plate in the burner assembly; not sure if the flame color will change w/ just map or propane burning. Not an ac guy and might not have this right, just do labor for my dad and brother who are. edit: or maybe w/ the halide torch you don't need the copper plate, either way I didn't know about detecting chlorine like that. Blackbeer fucked around with this message at 23:28 on Jul 10, 2017 |
# ? Jul 10, 2017 21:42 |
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I have an issue with a hot tub I was recently given. The issue is the heating element has a fault and when it's turned on it trips the house rcd. I tried testing and once out of about 5 tries got a small leak between the neutral and earth on the element. So the obvious solution in change the element and move on right? Well it turns out they are like hens teeth and coat around £75 when you do find one! So if I disconnect the earth cable from the element body it heats up fine, I gather this is stupid and only did it for a second. So... can I run this with the earth not attached and survive? My other solution is running an earth spike into the ground and run this to the element thereby avoiding tripping the whole house.
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# ? Jul 14, 2017 18:14 |
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water, electricity, no ground. Yeah that sounds like a great idea.
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# ? Jul 14, 2017 18:20 |
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Yeah but the earth strip... not a good idea?
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# ? Jul 14, 2017 18:22 |
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thegasman2000 posted:Yeah but the earth strip... not a good idea? In general, working around electrical faults instead of fixing them is not a good idea, yes.
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# ? Jul 14, 2017 18:25 |
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thegasman2000 posted:Yeah but the earth strip... not a good idea? No do not do this.
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# ? Jul 14, 2017 18:53 |
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Just make sure you jump into and out the tub to eliminate step potential. ....Replace the element or turn off power to the tub permanently, those are your only options. Connecting the element only to an earth spike completely removes the hot tub circuit from the low impedance earth fault path, and thus the breaker or fuse protecting the circuit will not operate even under a direct fault (ie, it wouldn't be a "short circuit", because you removed its ability to "short" to a dedicated earth path). It would be a probably painful way to commit suicide. angryrobots fucked around with this message at 19:00 on Jul 14, 2017 |
# ? Jul 14, 2017 18:54 |
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Spend the 75pounds.
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# ? Jul 14, 2017 19:17 |
HycoCam posted:
"Hot" tub, indeed!
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# ? Jul 14, 2017 19:19 |
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Point taken. Thanks for not getting me killed goons!
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# ? Jul 14, 2017 19:36 |
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angryrobots posted:Just make sure you jump into and out the tub to eliminate step potential. Can you explain this to me? Does the circuit breaker not operate on the hot wire? That is, if there was a short to his earth spike, why would that not trip the breaker? To be clear, I'm not questioning whether it is a bad idea, I just want to understand the specific reasoning for learning purposes.
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# ? Jul 15, 2017 02:49 |
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did we just give someone good hot tub advice and prevent a water + electricity death carnival? have we really lost our identity this much
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# ? Jul 15, 2017 02:58 |
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Steve French posted:Can you explain this to me? Does the circuit breaker not operate on the hot wire? That is, if there was a short to his earth spike, why would that not trip the breaker? To be clear, I'm not questioning whether it is a bad idea, I just want to understand the specific reasoning for learning purposes.
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# ? Jul 15, 2017 02:59 |
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SoundMonkey posted:did we just give someone good hot tub advice and prevent a water + electricity death carnival? Dang it--the better answer: Fill the tub with sliced carrots, potatoes, celery, and assorted spices.
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# ? Jul 15, 2017 03:01 |
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HycoCam posted:Starting in 2014 the US electrical code started requiring arc-fault breakers. every time i see something like this said, i can hear a disaster investigation show voiceover saying "but in this case,"
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# ? Jul 15, 2017 03:14 |
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Traditional breakers and fuses are there to keep the wiring in your walls from overheating and catching fire, not to prevent you from being electrocuted. 10 amps will happily cook you from the inside out without overloading a circuit. Replace that heating element AND make sure that circuit is protected by a GFCI (Ground Fault Current Interruptor), which does protect against electrical shock by measuring the current through both the hot and return conductors and tripping the circuit if they don't match.
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# ? Jul 15, 2017 13:42 |
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Steve French posted:Can you explain this to me? Does the circuit breaker not operate on the hot wire? That is, if there was a short to his earth spike, why would that not trip the breaker? To be clear, I'm not questioning whether it is a bad idea, I just want to understand the specific reasoning for learning purposes. An earth spike (or ground rod here in in the us) is for lightning protection, not fault clearing. That's why one is required at a service entrance, or at a remote building. If lightning strikes a building, or the power line, the ground rod will hopefully bleed off the energy, not allowing it to go any further. Lightning is a high impedance, high frequency, high voltage DC pulse and a driven ground rod is effective at dissipating that energy. The ground rod is always connected to the equipment grounding conductor (ECG), which most people just call the ground wire. The ECG's purpose is to serve as a low impedance path back to the source, for a fault, so that the breaker can operate as quickly as possible. That's why it's dedicated and never allowed to carry current. Removing this dedicated path, and attaching your ECG only to a ground rod is completely ineffective, any fault condition will almost certainly never be cleared by the protective device (breaker or fuse) because it's a very poor path. There used to be a video of someone demonstrating this by attaching 120v directly to a ground rod, but now I can't find it. There are a lot of good Mike Holt videos on this exact subject through, because it's unfortunately confusing even among electricians. The other posters are also correct that in this situation you also need GFCI protection. angryrobots fucked around with this message at 14:54 on Jul 15, 2017 |
# ? Jul 15, 2017 14:51 |
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shame on an IGA posted:Replace that heating element AND make sure that circuit is protected by a GFCI (Ground Fault Current Interruptor), which does protect against electrical shock by measuring the current through both the hot and return conductors and tripping the circuit if they don't match. angryrobots posted:The other posters are also correct that in this situation you also need GFCI protection. This was all precipitated by the home RCD, which is what the brits call GFCI.
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# ? Jul 15, 2017 15:30 |
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Having watched those Mike Holtz videos, this is my understanding of how things work. Corrections welcome, of course. The main thing to remember about electricity is that it only flows when there's a circuit, which means that the electricity has to get back where it came from. Normally that path is from the service, through the breaker, down the hot line, through the load (lightbulbs, appliances, etc.), down the neutral line back to the breaker, and back to the service. In the event of a ground fault, the path back from the load goes down the ground conductor instead of the neutral conductor; this still works because the ground conductor is connected to the neutral behind the breaker; the breaker can detect that it's sending current down the hot line and not getting enough current back on the neutral line, it flips, and your house doesn't burn down. (This might be only for GFCI breakers?) If you don't have a grounding conductor and get a fault (e.g. hot is directly connected to a metal casing), then no extra current flows, because there's no path from the fault back to the service. The faulty device can work perfectly well...but if you should happen to connect a conductor from the fault to the neutral line, you've closed the circuit. There's a new, low-impedance path from hot to neutral, and a ton of current will flow through that path. This should exceed the ampere limit of the circuit breaker and cause it to flip, but that won't save whatever the conductor was (hint: it's probably you) from getting a nasty shock. If you connect the grounding line directly to earth instead of sending it back to the breaker, then you're in a broadly similar situation to just not having a grounding conductor at all. The only route the circuit has to send current back to its source is literally through the ground (dirt and water and so on), which is not a great route. Bonus: you're at risk of energizing any metal pipes in the area.
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# ? Jul 15, 2017 15:36 |
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H110Hawk posted:This was all precipitated by the home RCD, which is what the brits call GFCI. That'll teach me to gloss over the very first line in the post, glad to see it's working as intended though I still have nightmares about that guy in the OSHA thread that measured 120 VAC between his bathtub faucet and drain
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# ? Jul 15, 2017 15:47 |
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Thanks, both super helpful informative responses.
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# ? Jul 15, 2017 16:49 |
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TooMuchAbstraction posted:Having watched those Mike Holtz videos, this is my understanding of how things work. Corrections welcome, of course. You just described a GFCI/RCD device. A normal circuit breaker is only measuring amps through the device, and can be gently tricked into going (sometimes way) over the rated amount. This is assuming either device (or a combo device) is working at all. Check my post in crappy construction for what happens when an old Zinsco panel is given overcurrent with no GFCI in place.
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# ? Jul 15, 2017 17:54 |
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H110Hawk posted:You just described a GFCI/RCD device. A normal circuit breaker is only measuring amps through the device, and can be gently tricked into going (sometimes way) over the rated amount. This is assuming either device (or a combo device) is working at all. Check my post in crappy construction for what happens when an old Zinsco panel is given overcurrent with no GFCI in place. it's extra fun when the age and condition of the breakers make them do weird things. every bar or club i've ever worked in has the worst wiring of any building i've seen in my life, like seriously don't go to clubs if you want to live. i flipped a light switch that made something dead short because Reasons, and the brand new 15A breaker nearest to it didn't trip, but the annoyingly soft 60 amp one in the sub panel did. i mean i'm sure it would have in a few more milliseconds but they can do weird stuff.
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# ? Jul 16, 2017 03:13 |
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SoundMonkey posted:it's extra fun when the age and condition of the breakers make them do weird things. every bar or club i've ever worked in has the worst wiring of any building i've seen in my life, like seriously don't go to clubs if you want to live. i flipped a light switch that made something dead short because Reasons, and the brand new 15A breaker nearest to it didn't trip, but the annoyingly soft 60 amp one in the sub panel did. i mean i'm sure it would have in a few more milliseconds but they can do weird stuff. I'm currently in a soviet-era russia themed gay bar in Manhattan, I'm going to stay very far away from anything related to electricity now
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# ? Jul 16, 2017 04:16 |
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minivanmegafun posted:I'm currently in a soviet-era russia themed gay bar in Manhattan, I'm going to stay very far away from anything related to electricity now "suspended ceiling" means "general purpose electrical crawlspace" btw. one place i worked in had so many extension cords (wire-nutted together then masking taped) running around up there it was hard to lift some of the ceiling panels.
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# ? Jul 16, 2017 06:08 |
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minivanmegafun posted:I'm currently in a soviet-era russia themed gay bar in Manhattan, I'm going to stay very far away from anything related to electricity now Aluminum wiring is part of theme, comrade!
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# ? Jul 17, 2017 03:41 |
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ahh. Our loving gas oven has stopped working again. gently caress. The clock and control panel work fine, the gas hobs work fine. But if you set an oven temp.... nothing happens. It appears that it should be working but you never hear the click and nothing heats up. I mean, I guess I am glad it was smart enough to not just dump gas into the room for the 30 minutes it took us to realize it wasn't happening... ha. (yes we do have carbon monoxide alarms) Can I fix this again with another $20 part? I was ready to buy a new oven last time but now I am mad about it
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# ? Jul 17, 2017 11:58 |
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other people posted:I mean, I guess I am glad it was smart enough to not just dump gas into the room for the 30 minutes it took us to realize it wasn't happening... ha. (yes we do have carbon monoxide alarms) A carbon monoxide alarm isn't going to tell you that your gas oven is just turned up to full blast but isn't ignited. Your nose should do that.
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# ? Jul 17, 2017 16:34 |
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other people posted:Can I fix this again with another $20 part? I was ready to buy a new oven last time but now I am mad about it Depends on the oven. Is it old enough that it has a standing pilot? If the pilot is out and can't be lit (follow the directions) then the thermocouple is bad. If it's not devastatingly old it probably has an ignitor. If you can light it by hand right after turning it on it's likely and ignitor. If you can't light it it could be a bunch of things, but likely the thermocouple/gas valve.
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# ? Jul 17, 2017 16:43 |
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You probably have a hot-surface ignitor, which are cheap and easy to replace. Thermocouples are also pretty cheap and easy to replace too if ^^^^^^^^^^ is your case. Blackbeer fucked around with this message at 18:52 on Jul 17, 2017 |
# ? Jul 17, 2017 18:45 |
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other people posted:ahh. Our loving gas oven has stopped working again. gently caress. Thirding that your problem is probably a very cheap and easy fix.
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# ? Jul 17, 2017 19:09 |
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# ? May 25, 2024 10:26 |
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Thank you guys. Is this what you mean? https://www.amazon.com/dp/B00ZFS3OQ4 I can have it gift wrapped so that's nice.
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# ? Jul 17, 2017 21:48 |