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| How to wire up a 240VAC receptacle |
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| Spork Schivago:
Ah shit. We might actually have to go for the transformer still. The P9S16A's are actually cheaper than the P9S13A's. We would actually be spending more money purchasing just one, let alone two. Cost effectively, I think it'd be a hell of a lot cheaper to just wire up the transformer. |
| james_s:
I do like the UK term "earth" for referring to what we typically refer to as "ground". You could ignore the fact that it's AC all together and think of this in terms of DC. If you take a pair of D batteries and connect them end to end you'll have 3V from one end to another. Now pretend that they're concealed and you can't see the + and - markings, that's fine because that information is irrelevant since your hypothetical load doesn't care about polarity. Now take a wire connected to the joint in the middle between the two batteries and attach that to a stake in the ground, now you can call that point ground or earth of you like. Now between the two remaining wires you'll still have 3V, but if you measure between either one and ground you'll see 1.5V. If you connect either one to ground you'll have a short. In DC you'd call it +1.5V and -1.5V but what really matters is the relative potential between two points and since the polarity is constantly changing with AC it's simpler to refer to it as phase. I don't know how it can get much simpler than this. |
| james_s:
--- Quote from: Spork Schivago on May 19, 2018, 10:35:07 pm ---Ah shit. We might actually have to go for the transformer still. The P9S16A's are actually cheaper than the P9S13A's. We would actually be spending more money purchasing just one, let alone two. Cost effectively, I think it'd be a hell of a lot cheaper to just wire up the transformer. --- End quote --- Remember that a transformer that size will be expensive and it will burn up a non-trivial amount of power just sitting there. I'm not familiar with the specific PDU's you're dealing with but I would be tempted to get a bunch of rack mount power strips and plug them into a row of standard 120V receptacles. You could easily install several dedicated 20A 120V circuits. |
| IanB:
--- Quote from: Spork Schivago on May 19, 2018, 10:35:07 pm ---Ah shit. We might actually have to go for the transformer still. The P9S16A's are actually cheaper than the P9S13A's. We would actually be spending more money purchasing just one, let alone two. Cost effectively, I think it'd be a hell of a lot cheaper to just wire up the transformer. --- End quote --- Remember that the transformer suggested earlier by Richard Crowley is 7.5 kVA. If that were to be fully loaded that would draw 7500 VA / 240 V = 31.25 A. Multiply that by 1.25 to get a continuous load rating (your server farm is a continuous load) and you get 39 A. So you would need to provide a 40 amp circuit using the recommended 8-gauge wire to a 40 amp breaker in the panel. You would not be able to run the transformer off an L6-30R receptacle, you would have to wire it in permanently. Then you would have to wire up the secondary side of the transformer to your PDU. You probably don't want to just put a fly-lead on the secondary with an IEC receptacle on it, so you will need to source an appropriate commercial use breaker panel that supports 240 V line to neutral with single pole breakers, and then install wall mounted IEC receptacle(s) to plug your PDU into. And then you have to get it to pass inspection. If you cost all that out, I think it might be cheaper just to buy the two new PDUs. |
| james_s:
Especially when you can get used PDUs for peanuts on ebay. |
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