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Panels are located in closets all the time. That's why they're called electrical closets. Note that the 36" clearance in front of the panel can be satisfied by opening the door (assuming the panel is opposite the door), the closet itself doesn't need to be 36" deep.
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Nov 3, 2012 08:46
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We're going to host a LAN party soon and we'll be using some 63 Amp lines (230V 3-phase, probably IT system) to power the whole thing. We have enough power for the LAN, but I want to be able to measure the load across each phase so we can monitor usage and catch any balancing issues before wires melt. The wiring is dead simple with 63 Amp master fuses in each distribution box, some 32A outputs and several 16A outlets. We'll probably connect the 32A outputs in these boxes to the 32A distribution boxes at the tables, and run short extension cords onto the tables from the 16A single-phase outlets. We did this two years ago with no major issues, but I would like to be more sure that this power system will hold, we're budgeting 1A average for each computer + monitor, there are a lot of laptops that will pull this average down. How do I monitor current, I can probably get hold of a clamp meter, there should be enough room to connect one on the 63A phases. Is it possible to measure voltage drop across fuses to determine current, or is that too unreliable? Also how do I calculate power in three phase? If I know the current in L1-3 and the voltage is 230V phase-to-phase, can I just do 230V times the current in each L-wire and sum them together? E: I have a vague memory of the square root of three being involved. longview fucked around with this message at 12:01 on Nov 5, 2012 |
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Nov 5, 2012 11:53
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longview posted:Also how do I calculate power in three phase? If I know the current in L1-3 and the voltage is 230V phase-to-phase, can I just do 230V times the current in each L-wire and sum them together? No, calculating power that way won't give you anything useful. 230V is the voltage between phases, but the current you're measuring is across the voltage between each phase and the neutral (230/sqrt(3)). You can either measure current in one phase, assume it's about the same in the others, and do VL-L*A*sqrt(3), or if you have the actual current on each leg you can just do VL-N*A for each leg and add them up. Unless things are way out of balance they'll be pretty close to each other and either way should give you a good enough estimate of the power.
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Nov 5, 2012 17:06
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E: I may have misunderstood your terminology, I'm reading up on this off-site! Ok thanks, but from what I'm told this is a older system which doesn't use a current carrying N wire (IT grounding), grounding is only a PE wire and a ground fault interrupter I think. If it was a TN type system I think we'd have 400V three phase (V_LL) and 230V V_L-N, whereas this may be a 230V V_LL system? In that case if my currents were pretty misbalanced at 5, 10 and 15A I could do 230V/sqrt(3) * (5+10+15) ~= 4kW? As an aside, if I understand TN systems, all the return current for all phases returns to the transformer over the N-wire when single-phase loads are connected? We're mostly interested in current during the LAN but knowing power usage would be nice to know for planning future events. I borrowed a Fluke hall-effect clamp probe to measure current (and promptly broke off a piece of plastic in the clamp so we have to glue it). longview fucked around with this message at 17:39 on Nov 5, 2012 |
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Nov 5, 2012 17:26
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Oh god, don't make me take out my textbooks. It's been too long for me to remember off the top of my head, but if I'm understanding you correctly you have a 3-wire delta system and in that case I think for unbalanced loads the power is just Vab*Ia+Vbc*Ib+Vca*Ic. I've been out of school too long to be sure though. You could assume 230V for each of those voltages to simplify things but it would be better to measure current for each phase and voltage between phases at the same time.
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Nov 5, 2012 18:53
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Dumb question for 3 phase stuff. How are you going to run a bunch of 120v/240v laptops and desktops off a delta 3 phase system without a delta-wye transformer? I've never really truly understood 3 phase in any way except 3 phase generator powering a 3 phase load, and delta still confuses me a bit, while wye makes sense and high-leg delta mostly makes sense to me.
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Nov 5, 2012 21:04
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In this system we just connect single phase loads between to arbitrary phases, this is how pretty much all house intakes are right now in Norway at least. Modern installations (not what we'll be working with) have 400V three-phase so we can put loads between L_1-3 and N and have 230V. The reason for this as far as I know is that we have stayed with isolated transformer grounding for far longer than the rest of the world, so there's no N conductor, just two L wires in each outlet. PE is provided by a ground-spike, and doesn't normally carry current (leading to a number of grounding issues, the grounding spike is not guaranteed to be super low impedance, unlike the PE-N wire in a modern installation). Our old house was only GFCI protected on the bathroom lighting circuit, on the other circuits current could flow in the PE wire and nothing was guaranteed to break the current.
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Nov 6, 2012 00:06
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kastein posted:Dumb question for 3 phase stuff. How are you going to run a bunch of 120v/240v laptops and desktops off a delta 3 phase system without a delta-wye transformer? I've never really truly understood 3 phase in any way except 3 phase generator powering a 3 phase load, and delta still confuses me a bit, while wye makes sense and high-leg delta mostly makes sense to me.  Most computer power supplies don't care whether the neutral is grounded, and will just as happily work between any two phases of 60Hz 208V delta.
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Nov 6, 2012 01:45
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OK, that's what I thought. I may end up doing the panel myself, I guess I just need to schedule the utility to disconnect/reconnect. I'm not sure how they handle it around here as my meter doesn't interrupt the current when removed (apparently? don't ask me but when they swapped in a smart meter I didn't lose power). All utilities are underground which is great because I almost never lose power... Our transformers are hooked to the substation entirely underground so it takes a large outage to knock us offline. But I think the disconnect for my house is buried in my neighbor's yard somewhere.
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Nov 6, 2012 05:44
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Correct, though the largest "normal" outlet for single phase is 16A, larger than that you need special plugs. 25A is used for electrical stoves, typical intake is 63A 230V (delta) three phase or 63A 400V Y three phase for new installations. Almost all the circuits in our house are 13A, which is the new standard lighting/small heater circuit. I've heard stories from lands where plugs are polarized and TN grounding is standard people will wire the chassis ground to Neutral if PE isn't available... obviously this breaks down completely when you use it in Europe where most plugs aren't polarized, so there's no guarantee your blue N wire is actually N. longview fucked around with this message at 10:00 on Nov 6, 2012 |
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Nov 6, 2012 09:57
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Ender.uNF posted:OK, that's what I thought. I may end up doing the panel myself, I guess I just need to schedule the utility to disconnect/reconnect. I'm not sure how they handle it around here as my meter doesn't interrupt the current when removed (apparently? don't ask me but when they swapped in a smart meter I didn't lose power). Many types of meters have a bypass where the POCO can put jumpers while they swap meters.
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Nov 6, 2012 11:33
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This weekend, I plugged my 6 Amp shop VAC in an outlet and everything on the 15 Amp circuit went out. I went downstairs to check the breaker, and it wasn't flipped off (this is an old Pushmatic box). So I pressed it on and off again, and nothing happened. So then I turned everything off on the circuit, and opened up the first junction box, turned the circuit on the measure voltage. 120 volts. Everything was on and working normally. What's going on here?
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Nov 12, 2012 15:33
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daslog posted:This weekend, I plugged my 6 Amp shop VAC in an outlet and everything on the 15 Amp circuit went out. I went downstairs to check the breaker, and it wasn't flipped off (this is an old Pushmatic box). So I pressed it on and off again, and nothing happened.
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Nov 12, 2012 17:14
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Alrighty, so I posted earlier about how I was going to add new runs for my fridge and dishwasher and then get an electrician friend of a friend to come by and doublecheck that I hooked up the breakers and everything correctly. I've gone through the entire house and matched up every outlet and device to its breaker, but have now run into a snag with the panel itself, an "ITE BL Loadcenter". Since ITE is no more (picked up by Siemens), and its hardware seems to be discontinued or about to be, breakers cost roughly $50 apiece compared to $10 for everything else. Cool, whatever, I'll pay the premium (even though I can't actually source a 20A breaker at the moment!), but our basement is unfinished, and I'm probably going to be running more outlets and maybe a subpanel to our attached garage in the future etc. So now I'm reevaluating whether I should just upgrade the whole breaker panel. Our meter and the service box both read as 200A. I called my local Hydro to see if I was actually hooked up for 200A from their end at the pole and not just futureproofed or whatever, but they don't have records of that kind, or maybe it's a stupid question. I'm assuming I'm good to go for 200A as it is? Anyways, despite being stubborn and curious, and wanting to do everything myself, the work involved may be rapidly approaching "burn your house down" territory. Apparently I can pull all the permits and legally hook up a new panel myself, then get the hydro inspector to check off on it, but I should probably stop loving around and just pay a pro to do it.... is replacing a breaker panel a huge job for an electrician (more than 1-2 hours labour?). Does the hydro company need to shut the service down to replace the breaker panel? I'm thinking I'd probably buy the new panel, and a subpanel for the garage, run the cable to the garage and have the electrician do all the panel hooking up.  e: going to call for a few estimates, Canadian Remembrance Day and everyone being closed is holding me up this weekend Pweller fucked around with this message at 20:56 on Nov 12, 2012 |
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Nov 12, 2012 17:53
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grover posted:Could be a loose connection somewhere. They're the worst to troubleshoot. Check the neutral, too. It ended up being a loose wire in a 4 way connection box. Fixed by very carefully twisting the 4 wires and putting the correct sized wirenut. People complain about building codes, but they don't own a house built in 1962 like I do...
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Nov 12, 2012 23:49
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Pweller posted:... is replacing a breaker panel a huge job for an electrician (more than 1-2 hours labour?). Does the hydro company need to shut the service down to replace the breaker panel? Yes. You absolutely need the meter pulled to replace the panel. Otherwise, you'll be lucky to burn your house down. Unlucky if you manage to do it by setting yourself on fire first. Once the service is off and the wire is pulled, then hooking up the panel is the easy part. So easy that DARPA has trained chimpanzees to do it (not quite, but it's that easy). It's just time consuming. To walk up to a dead panel, label everything, pull it off the wall, new panel on, everything reconnected and checked is probably four hours for someone good. This assumes no snags like "wire isn't long enough" or "these two circuits share a neutral, but one of them must be AFCI and one must be GFCI" or "Nothing, at all, in any way is up to code in this room." That's why a service upgrade starts at $1000 for "really good friend" prices, and is more like $2000-5000. You can do it yourself in a good Saturday if you have good light and the power company obliges you.
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Nov 13, 2012 13:03
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daslog posted:It ended up being a loose wire in a 4 way connection box. Fixed by very carefully twisting the 4 wires and putting the correct sized wirenut. Ugh. My grandma isn't doing too well and my grandpa passed away 8 years ago. They're the original owners of their 1954 house which will probably be on the market sooner rather than later, unfortunately. Well, my grandpa, god rest his soul, was probably the worst handyman I've ever known. My grandpa was known for his liberal use of Liquid Nails for everything. That means that it will probably fall onto me to fix up the electricity in this house before it can be sold again since I'm the grandson that "knows how to fix things" and I'm dreading it. There's actually a funny yet dangerous story of ~20 years ago where he replaced the back porch light with a new motion sensing one. Later that day, my grandma got shocked and yelled out after turning on said light, then touching the switch and the door frame at the same time. An argument ensued and she stormed out of the room, so my grandpa turns to my uncle sitting at the kitchen table and tells him, "She can't take a few volts." At least he was funny.
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Nov 13, 2012 18:34
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Pweller posted:I needs a new electric panel I'm sure price varies by location, my swap for from a 100A bus panel to a new 250A 40 slot breaker panel (along with a new mast, appropriate grounding rods, etc) cost me $2,500USD in Washington State. My power company also decided to replace the meter that had been in the home since manufacture in the 1960s with a newfangled digital one and my power bill has dropped $20-25/month
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Nov 13, 2012 22:07
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I posted about these last year I think: USB receptacles finally hit the mainstream and are available for purchase now. http://www.amazon.com/Leviton-T5630-W-125-Volt-Tamper-Resistant-Receptacle/dp/B008O11IEY http://www.amazon.com/Cooper-Wiring-Devices-TR7740W-K-Combination/dp/B007NC5GI4 Looks like they got around the need for special faceplates by removing one of the jacks.
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Nov 15, 2012 17:23
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I've seen ones with two receptacles and two USB ports. Are any of these actually available?
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Nov 15, 2012 23:11
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AmbassadorTaxicab posted:I've seen ones with two receptacles and two USB ports. Are any of these actually available? The ones with a duplex and the USB ports need an extra deep backbox. I believe they are available for sale, a Leviton rep brought one into work last week.
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Nov 15, 2012 23:20
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Are these any better than leaving a power adapter plugged in all the time? I still lose a plug, and it still sucks down power when not in use. Having two plugs and two usb ports would take care of the first problem, but wont the USB ports get covered up if you have a transformer plug?
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Nov 16, 2012 00:04
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Guy Axlerod posted:Are these any better than leaving a power adapter plugged in all the time? The spec sheets say there's a smart chip that intelligently powers the chargers. I suspect the SMPS controller doesn't even turn the thing on until something is plugged in.
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Nov 16, 2012 02:51
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Hey all, I just ordered a new electric range and the salesman told me I needed a 4 prong cord for it. I went home and see that my existing range and outlet are a three prong. What is my best course of action here? Can I use (reuse existing cord?) a three prong cord on the new range or can I relatively easily swap out the 3 prong outlet for a 4 prong? Will the necessary wires be in the wall to accommodate the 4 prong outlet? Thanks!
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Nov 17, 2012 18:54
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TraderStav posted:Hey all, I just ordered a new electric range and the salesman told me I needed a 4 prong cord for it. I went home and see that my existing range and outlet are a three prong. What is my best course of action here? Can I use (reuse existing cord?) a three prong cord on the new range or can I relatively easily swap out the 3 prong outlet for a 4 prong? Will the necessary wires be in the wall to accommodate the 4 prong outlet?
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Nov 18, 2012 01:34
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grover posted:You need to get a cord that matches your outlet. The easiest way to do this is to take the cord off your old range and re-use it. The manual for your new range will tell you how to properly wire it up- it's common (and OK) to bond the chassis of the range to the neutral wire, though still best to use a grounded 4-prong cord/plug if feasible. Thanks, I ended up going to the store and swapping for a 3 prong as the installers are going to set it up. They won't reuse an old cord and frankly, I'm more comfortable with them setting it up despite how easy I'm sure it is. $23 for piece of mind, I'll take it. I'm just glad I grossly misunderstood the situation at the store and I needed to match the cord to my home, not my home to the cord...
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Nov 18, 2012 01:39
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Stupid question time, I'm wiring up an extractor fan with a household plug because I'm building a food dehydrator, I'm sure I've wired both the fan and the plug correctly, and the fan works when I test it in a socket, but it won't work in the power strip I want to use (which I know is good, and I've tested it in another power strip and it doesn't work there either). What could I be doing wrong? (I'm in Europe, so 220v weird plugs etc...)
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Nov 19, 2012 15:08
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Weird. Try this for a test: when you plug that fan into the power strip and turn it on, does it also disable the other plugs on that power strip?
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Nov 20, 2012 17:28
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kid sinister posted:Weird. Try this for a test: when you plug that fan into the power strip and turn it on, does it also disable the other plugs on that power strip? Nope, tried that, the others all work, however, I have noticed that while it works in the wall sockets, if I flip it over in the same socket (European plugs can be plugged in both ways) it stops working.
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Nov 20, 2012 18:54
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Try wiggling the cable, maybe there's a broken wire?
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Nov 20, 2012 20:45
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yaffle posted:Nope, tried that, the others all work, however, I have noticed that while it works in the wall sockets, if I flip it over in the same socket (European plugs can be plugged in both ways) it stops working. I don't mean to insult you by asking the obvious question, but have you tried turning the plug around in the same outlet on the power strip, or turning the power strip's plug around in the wall outlet?
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Nov 20, 2012 22:57
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yaffle posted:Nope, tried that, the others all work, however, I have noticed that while it works in the wall sockets, if I flip it over in the same socket (European plugs can be plugged in both ways) it stops working. Sounds like you might have wired one side of the fan to the protective ground (earth) contact instead of the neutral prong. This is not correct, but it will make the fan run if there is no GFCI or similar in the socket side of the circuit. When you flip the plug over, this becomes a connection to the protective ground and neutral, which obviously isn't going to make the fan run. If your fan has a three-wire connection, this means the third wire, which would be the actual protective ground wire of the fan, will now be connected to a live prong. So if your fan has external metal parts (which are supposed to be grounded), they may become live with 230 volts AC when the plug is in the non-working orientation. Please check your wiring, and if necessary, remove the miswired plug ASAP. (In the European system, live and neutral are supposed to be interchangeable, but the protective ground will not switch places if you flip the plug.) And the power strip might have an issue with its protective ground, or the strip might simply be plugged into a non-grounded outlet. The plug orientations would then work out to either live+nothing (protective ground in neutral, so probably safe) or neutral+nothing (with the exposed metal parts of the fan possibly becoming live).
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Nov 21, 2012 00:06
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I've got an electrical outlet at one of our stores that has been shocking employees lately and I can't figure out why, always through devices plugged into it. I figured it had to be their gear being plugged in, but the list of devices that have shocked people keeps growing. There aren't any scorch marks on the outlets or inside the box either. What gives?
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Nov 25, 2012 20:43
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kid sinister posted:I've got an electrical outlet at one of our stores that has been shocking employees lately and I can't figure out why, always through devices plugged into it. I figured it had to be their gear being plugged in, but the list of devices that have shocked people keeps growing. In either case, the most likely culprit is a bad ground that's been shorted out, thus energizing the case of anything plugged into it. Another potential culprit is a good ground that's merely providing a path to ground from nearby ungrounded metal that's energized.
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Nov 25, 2012 20:51
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My guess is they are touching metal piping or something connected to it, and the ground is faulty on the outlet. Alternately the outlet is good, and whatever else they're around is not.
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Nov 25, 2012 22:19
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So...long story but my house currently is hooked up with two wire service on a 3 wire panel with a jumper across the two hots. The power co. will eventually hook up the third wire and hopefully they give notice and I can remove the jumper. Lets say I don't remove the jumper though, would anything terrible happen if they connected the third wire? Anything plugged in and switched on Id expect to be fried from 220v, ya? I'm just worried the power co. is going to just show up one day and connect it without notice dwoloz fucked around with this message at 23:11 on Nov 25, 2012 |
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Nov 25, 2012 23:06
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dwoloz posted:So...long story but my house currently is hooked up with two wire service on a 3 wire panel with a jumper across the two hots. In the meantime, you can temporarily move all the breakers you really care about onto the one live phase and remove the jumper.
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Nov 25, 2012 23:12
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Are they aware of the phase to phase jumper? If they are, there's no way in hell they'll hook up the third wire without either removing the jumper or asking you to have it removed. Fireworks would ensue. Who put the jumper in? That's a bit sketchy, though I can see it being useful in an emergency of some sort.
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Nov 26, 2012 00:26
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I'm replacing a few receptacles for my mom and when I pulled them out of the wall they didn't make sense to me. There are two split receptacles and the top outlet on each is controlled by a single switch. The back of these receptacles have 8 of the quick insert terminals and no screw terminals except for the ground. One box has a 2 conductor + ground cable and 3 conductor + ground cable in it:  The tab on the hot side is broken off, but the neutral side is still there. The other box has two 3 conductor + ground cables in it:  Again, the tab on the hot side is broken off, but the neutral side is still there. The new receptacles have a screw and quick insert terminal for hot and neutral for each socket. How should I wire these up?
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Nov 26, 2012 00:39
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Cpt.Wacky posted:How should I wire these up? Carabus fucked around with this message at 04:08 on Nov 26, 2012 |
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Nov 26, 2012 04:02
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