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| How to wire up a 240VAC receptacle |
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| Spork Schivago:
--- Quote from: Richard Crowley on May 16, 2018, 05:43:22 pm ---... --- Quote ---I am going to study the wiring diagram again and re-read what you wrote, to see if I can understand it more clearly. I'd connect H1 and H7 together, and then run 120VAC to H1 and H7. I'd connect H10 and H4 together, than run the other hot from the double pole to H10 and H4. We have 200-amp coming in. I told my wife, we might need to upgrade that to 400-amp. She wasn't happy about that at all, seeing how we just paid to go from 100-amp service to 200-amp service. --- End quote --- NO! Nobody mentioned 120VAC anywhere. The transformer will take the split-phase 240V from your domestic service and turn it into 240V "single-phase", ground-referenced which is what the HPE PDU is designed for. If you try to connect that transformer to a 120V circuit, you will be lucky if only the breaker blows. --- End quote --- It was the 2nd and 3rd post I made where I said it was a PDU going into a rack and gave the model number, you are correct. I actually tried uploading pics of the plug and in that post, I believe I actually wrote a statement saying that because PDU can mean multiple things, blah, blah, blah, this was for a rack and would run computer equipment. But for some reason, that post never made it threw. So, I run both "phases" or "mains" into H1 and H7, after tying them together? and then neutral into H10 and H4 together? My wife just got home and I'm the only one who watches my daughter while she's at work, so I can't do much with the business until she gets home. I can post a list of exactly what loads we have (or at least, what power supplies we have). I think C said there's no way to safely do this though. So if the transformer is wired correctly, I'm a bit confused as to why some say it will work, some say it won't. We have also sent a message to our licensed electrician, but that's a pain now. We were offered some contracts, they're a one time thing. It's not what we want to do with our business, but we took them. We know someone who knows someone and a company or two outsourced to us. Having someone down there, even to wire it up means we gotta get it approved by at least one of the companies, if not both, have the electrician sign an NDA, etc. It becomes a real pain. In my jurisdiction, I can provide the sketch myself. We did that when we wired the low-voltage wires for our daughter's room, so we're familiar with the process there. Here, we can run ethernet, for example, between two floor joists that connect to the cold-air return, but only if we use plenum grade ethernet. We don't actually run it down the ductwork, we run it outside of the duct-work. But if it wasn't plenum grade, we wouldn't be able to do that, unless we used conduit or something along those lines. |
| Spork Schivago:
--- Quote from: Richard Crowley on May 16, 2018, 05:58:36 pm --- --- Quote from: Spork Schivago on May 16, 2018, 05:16:04 pm ---Why would that transformer Mr. Crowley linked to get someone hurt? --- End quote --- Easy. By improper installation, incorrect connection, etc. It is unfortunate when somebody powers a little 5V board from 12V and turns it into toast. But is is a whole different ballgame when you are talking about thousands of watts of power that could kill your whole family AND burn down your house. --- End quote --- Yes, I understand that, but _if_ it's wired correctly, the way C was responding, it sounded like it was just wrong and wouldn't work. Even DC can be dangerous and kill you. I try to treat all electricity as the same. I don't have special rules just for low-voltage sources. I try to practice safe standards everywhere, even if there isn't necessarily a threat or chance for personal injury. That way, it becomes a bit of muscle memory. --- Quote ---When you say non-standard, do you mean not-common, or it violates some standard somewheres? --- End quote --- Didn't you answer that yourself when you said that the electrician would not connect to the IEC Euro-connector? Of course, maybe that was just someone who does domestic wiring in private homes. Not surprising that they would shy away from an unfamiliar connector. But if you were talking to an electrical contractor that does big commercial and industrial projects, they may have had a very different response. --- Quote ---When we were looking into three-phase, an alternative the electrician gave us was a transformer, although there where some down-sides, if I remember correctly (which I might not remember correctly) about using it, compared to direct three-phase. I think he said something about it wouldn't be "true" 3-phase. It would look like it, but wouldn't be as clean or something. I took it (just as a comparison) as comparing a digital oscilloscope to an analog. The analog will provide a true sine wave, but a digital will try to emulate it, buy drawing lots of little tiny squares (or whatever) to make it appear as a sine wave. --- End quote --- --- Quote from: Richard Crowley on May 16, 2018, 05:58:36 pm ---Yes, people who buy big industrial machines (lathes, milling machines, etc.) to put in their garage are faced with the problem that big motors operate on 3-phase power which is very rare here in North America in private homes. So there are all sorts of gadgets from rotary converters (a single-phase motor driving a 3-phase alternator), or electronic circuits that create 3-phase, to dodgy resonant contraptions that put out pseudo-3-phase. But you do not need 3-phase. You are having enough problems just getting 240V single-phase. And the PDU you selected isn't suitable for a 3-phase source any more than it is suitable for 240V split-phase. --- End quote --- Yes, I know I don't need three-phase. We made the choice for 1-phase because of costs. I was using that just as an example. I was thinking maybe what C meant was with the transformer, it wouldn't be considered true 1-phase 240VAC. It'd be pseudo-1-phase 240VAC and would possibly not be safe, for example, with the devices that are US made with the 120VAC / 240VAC switch on the PSUs, or with the actual PDU itself. Do you follow what I was saying now? Thanks. |
| Spork Schivago:
--- Quote from: IanB on May 16, 2018, 06:37:51 pm --- --- Quote from: Spork Schivago on May 16, 2018, 04:33:42 pm ---As for the cooling, eventually we will get central air, but right now, being in the basement, we've kinda got lucky. Throughout the year, it seems to maintain an almost stable temperature and is cool. --- End quote --- Hopefully you realize that will only be true as long as the basement is not full of computer equipment? At work our server rooms always have to have big powerful aircon units in them. If for any reason the aircon unit fails the temperature in the room skyrockets, alarms go off, and then all the equipment shuts down due to overheating. What you need to do, if you haven't already done it, is to add up the power consumption of all the equipment in the basement (seems like it could be around 7 kW based on the size of the PDU?), and then determine how you are going to remove 7 kW of heating from the room. You can imagine that if you put a 7 kW electric heater in your basement it is not likely to maintain a stable, cool temperature... --- End quote --- Yes, we know that it will heat up quickly when we start powering the equipment up, and have plans for a central air conditioning unit. Until then, we have A) a portable unit we can use B) a wall unit we can use. They're not the best options, but they can work until we have the central AC installed. We did add up all the equipment and currently got around 5kW, but that was excluding the upgrades that we are planning on purchasing. With the extra's, yes, we'll be around 7 kW, then during phase three, we'll be even higher, and will need another PDU. At that point, hopefully we have enough income to get a dedicated panel just for the business though. Removing 7 kW of heating is something I hadn't put too much thought into. I didn't think of it like that, so I like that idea. We remove the condensation from the room, which makes it feel cooler and doesn't provide danger to the equipment (condensation tends to rust equipment, might even short parts out, etc). We do need to have the outside of our house tore up and properly sealed, but that's later on. We have special sensors to monitor the temperature of the equipment in the rack, and it's designed to send us various messages, set off alarms, if certain conditions are met. One of them includes heat. If heat gets too high, we get cell phone messages, and there's a program written that should set off one of the alarm systems down there. At my old work, in the server room, they had residential ACs running and just dumping the water between the cement walls, which was a horrible idea, but it saved them money. Eventually, this caused a lot of problems for the company with things like mold. So in the end, it costed them more money than they saved. We also plan on purchasing a whole-home generator, that will be installed by a professional, with an automatic transfer switch, and we still need to figure out the UPS setup, where it can power the equipment long enough for the whole-home generator to kick on. That's one of the biggest reasons we took on the first contract. It's getting close to being finished and pays us a good amount of money that should allow us to finish purchasing those things I just mentioned. |
| Spork Schivago:
Right now, we're currently at 6,360 watts, assuming full load on all devices. That's what all the name plates, added up, come to. Keep in mind, most systems shouldn't be running at exactly what the power supply is rated for. They should be running at around 80% or so of what the power supplies are rated for. Almost all the devices don't have a switch for 240VAC, but they say 115 to 230VAC for input. And reading the technical manuals, they auto-detect and expect single-phase. There are some other devices that we're using, but they're not rack-mountable, so we did not include them, like the BGA rework station that claims it draws 4,800 watts. It's using Elstien heating elements for the pre-heater part, but it's a cheap Scotle unit. Just something we bought a few years back to get us up and running. They're not powered by this PDU, but are connected to the same panel as the PDU's transformer will be connected to. I think I will go for the 10kVA one. |
| james_s:
Remind me what this is all for? IMO by the time you get to several kW of computer gear in the basement, it's time to start looking for a proper data center. |
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