Need help wiring up 240VAC.

[goontron]

Re: Need help wiring up 240VAC.

u.s. electrical standards are a fucking trainwreck!
btw, how the hell did that NEMA blade-contact stuff ever get accepted???
it has no shielding from water or small metal objects getting down the edge.

in most of the world the plugs either have shielded pins, or the socket atleast has a "rim" that covers the edge of the plug to some degree or other.

Our plug design is only a couple decades newer (circa 1920s) than the Edison company screw base (circa 1900s). It's a hundred fucking years old, its not going to have any safety standard close to more modern plugs like the UK plug that has evolved at least twice. And frankly i see no need to change it. Low voltage, low current, higher frequency….

[Spork Schivago]

Re: Need help wiring up 240VAC.

So those circuit breakers are definitely a problem, the built-in ones. They're single-pole and either need 1-phase 240VAC or I need to replace the PDU.

I've decided I'd like to provide the 1-phase 240VAC using this transformer:

https://www.galco.com/buy/Acme-Electric/T-2-53517-3S

Here's a link to the wiring diagram:

https://cdn.badcaps-static.com/pdfs/...73b4930acc.pdf

I'm looking at number 4.

If I read this correctly, I tie H1 and H7 together. Than I run both my 120VAC double pole breaker hots to H1 and H7. I tie H10 and H4 together. I run my Neutral line to H10 and H4.

I tie X2 to X3. Then X1 would be 240VAC single phase? Or X4 would be? Or either one, doesn't matter, and X1 or X4 goes to hot, the other goes to European outlet Neutral?

[budm]

Re: Need help wiring up 240VAC.

General Purpose Transformers, T Series
Item# T-2-53517-3S
Transformer, 15KVA, 1Ph, Enclosed, 240/480VAC Pri, 120/240VAC Sec Four Windings, Wall Mount
That is 15KVA, you need that much power and that many taps?
You still need to feed the 240V winding through Double pole breaker since you will still be using L1 and L2 from your circuit breaker panel, no neutral, you need breaker due to the fact that you can have transformer failure.

[stj]

Re: Need help wiring up 240VAC.

one thing to point out, this is a 240v panel.
all the outlets will be 240v.
keep that in mind when buying stuff to plug into it.

there is a simple fix to the original problem, but the state will probably hang you for it!!
use the 2 lines (240v)
and run the ground out to a big copper groundspike - do NOT reference it to your house ground or let it cross-feed into the domestic ground wiring.

[budm]

Re: Need help wiring up 240VAC.

So those circuit breakers are definitely a problem, the built-in ones. They're single-pole and either need 1-phase 240VAC or I need to replace the PDU.

I've decided I'd like to provide the 1-phase 240VAC using this transformer:

https://www.galco.com/buy/Acme-Electric/T-2-53517-3S

Here's a link to the wiring diagram:

https://cdn.badcaps-static.com/pdfs/...73b4930acc.pdf

I'm looking at number 4.

If I read this correctly, I tie H1 and H7 together. Than I run both my 120VAC double pole breaker hots to H1 and H7. I tie H10 and H4 together. I run my Neutral line to H10 and H4.

I tie X2 to X3. Then X1 would be 240VAC single phase? Or X4 would be? Or either one, doesn't matter, and X1 or X4 goes to hot, the other goes to European outlet Neutral?

I re-read this again, so are you doing the step down from 240VAC to 120VAC, or are you doing the step up from 120V to 240V?

[stj]

Re: Need help wiring up 240VAC.

neither, he wants to isolate the 240v so it's not referenced to ground 50-50 and he can bond the ground and neutral together. AFAIK.

[Spork Schivago]

Re: Need help wiring up 240VAC.

I re-read this again, so are you doing the step down from 240VAC to 120VAC, or are you doing the step up from 120V to 240V?

I am attempting to go from 240VAC split-phase (120VAC - 0 - 120VAC) to 1-phase 240VAC, with a 1:1 ratio. Instead of having two 120VAC hots, I have one 240VAC hot, the way most of the equipment I have purchased was designed to work, the way the PDU has to be wired up.

If I run 120VAC to the Neutral on the PDU plug, then the internal breakers, if they trip, aren't affective, being one-pole, instead of 2-pole. There'd still be 120VAC going down to the equipment. The only protection I would get would be from my upstream breakers, if that makes since.

Right now, we're 6,360 watts, assuming full load. With possible future upgrades, we would need the 15kVA. I figured now would be the time to purchase the 15kVA, rather than when we actually purchased those upgrades and needed them. Otherwise, we'd have to pull the lower rated transformer, spend money on a higher rated transformer, rewire it, etc.

We have a lot of power hungry devices here, unfortunately.

[Spork Schivago]

Re: Need help wiring up 240VAC.

neither, he wants to isolate the 240v so it's not referenced to ground 50-50 and he can bond the ground and neutral together. AFAIK.

Not sure what you mean by 50-50, unless you mean 1 to 1, but other than that, yes, you're correct.

We need to have the European "Earth" and Neutral bonded to our Neutral and ground, so the internal breakers on the PDU properly protect the equipment if something trips the breaker. If we have 120VAC running down Neutral, with the internal breaker tripped, it will STILL provide 120VAC down the Neutral. It would kill the 120VAC going down the L/+ line, but that's it.

So we need to go from what I call split phase 240VAC to 1-phase 240VAC.

1 wire that provides 240VAC in reference to ground, two wires that provide ground. That should be the output of the transformer.

Just never having rigged up one of these, the pictures confuse me a bit. If there's a better transformer for me to use, let me know. I'm not sure what the taps mean....

[Per Hansson]

Re: Need help wiring up 240VAC.

Surely buying the correct PDU for the US would be allot cheaper than a big ass transformer to basically ghetto mod this?

The correct way to ghetto mod the PDU would be to replace it's internal breaker with a double pole so you can use it with split phase 230VAC safely.

[Spork Schivago]

Re: Need help wiring up 240VAC.

Yes, but then we need to figure out how to modify the PSUs for the servers. HPE did an assement for us and based on what we have, they determined the only option for the servers where the 240VAC PSUs, which I personally think was bullshit. Two sockets per server and even though the video card is gonna draw a bit and the CPU is gonna draw a bit and the hard drives are gonna draw a bit, it makes absolutely no sense to me why we needed two of the largest PSUs they make for the servers per server. We're using one of the sockets, not both. So, what are we supposed to do when we purchase hardware for the other sides of the servers? I think they just saw an option to up sell and did just that. Chances are good, we probably could have gotten away with the 800 watt 120VAC PSUs. So, if I tear into the PDU to replace the breakers and wire and plug, I void the warranty and because we've installed it, not realizing the problem, we're stuck with it. And same with the PSUs. We installed them, we tear them apart, we void the warranty. It's a mess, but I guess that's what happens when you let a company like HPE do an electrical assement for you....

[Spork Schivago]

Re: Need help wiring up 240VAC.

I typed that on my cell phone. I didn't address the buying the correct PDU question.

In order to provide enough current for our rack mount devices (or the devices that are going to be hooked up to the PDU), the only US options available, without changing manufacturers (which is something we'd rather not do at this point in time), would be to purchase two smaller units and daisy chain them together, which actually ends up costing us more than this unit and the transformer, believe it or not.

But we're still stuck with the PSU issue. According to HPE, with our current setup, these power supplies are the ONLY power supplies for our server that can handle our hardware. If we assume they are correct, and our servers are each drawing 1,400 watt per server (we use one as a redundant PSU), then there is no way to do this, as far as I can tell, without having the transformer.

The PSUs are three prong, just like the PDU. The PSUs expect 240VAC, so I'm _guessing_ they expect it down one line. I'm checking through the datasheet now to see if we can provide it the way Stj originally suggested. If so, then maybe voiding the warranty on the PDU isn't such a bad idea and just replace the two internal breakers with double pole, replace the power cord with one really large power cord that accepts the US 120VAC - 0 - 120VAC split-phase (or what I call split-phase).

[Spork Schivago]

Re: Need help wiring up 240VAC.

I double checked with HPE, and according to the technician I talked to this time, the PSU's are correct for our setup. The servers won't even turn on without the 1400 watt, and they're only single phase 240VAC. They do not make a 1400 watt split-phase. So as far as I can see, the only option is the transformer.

Assuming the HPE techs aren't giving us a line of bull. They said if we tried providing split-phase to the PSU's, the PSUs won't power on, the server won't power on.

[stj]

Re: Need help wiring up 240VAC.

you can wire it, it's just people's concerns if there is a fault.
one solution is to wire it the way i originally said, and include a 32A RCD.
then if the load goes out of balance due to a fault, both the lines should instantly be cut.

[Spork Schivago]

Re: Need help wiring up 240VAC.

But if I wire it using what's currently coming into my house and something breaks, HPE is NOT going to warrant that stuff at all.

That's why I'd rather just use the transformer and provide the 1-phase 240VAC they claim my PSUs will only run on. For what it's worth, after their power assessment, they said these 1400 watts where my only option. I had more options if I had 3-phase, but after talking to our electrician and the local power company, that wasn't an option.

Now, we're thinking maybe the electrician over exaggerated the price for one reason or another (he said it'd be over 50k), but that included costs for backhoes, etc. Keep in mind, we're zoned for Residential, not commercial. Don't know if that makes a difference.

According to the HPE techs (I've discussed this with them multiple times, with different techs. The ones that are really the techs, and then the post-sales number you call) and they all swear up and down that these PSUs WILL NOT power on with the split-phase and say I _need_ the 1 phase 240VAC.

7 pages of people (including me) arguing that over and over and over again on another forum. I just wanted to know how to wire up the transformer! But some swear up and down the PSU will work with split-phase.

I know it isn't just a normal PSU. It has something near the input plug where I can hook it up to an intelligent PDU and they communicate together, which might be why they say it requires single phase 240VAC. I dunno. At their prices, I'm not going to tear one apart to see if it can really run off the split-phase, and I'm not gonna spend money on the wires and receptacle and send the PDU back and purchase two of the ones designed to run off the split-phase, just to see.

I'm just gonna take their word for it and purchase the transformer and hopefully, with the help of the kind folks at BadCaps.net, we can figure out how to properly wire it up safely.

I'm still going to get the permits from the city and I've called my electrician to see how much it'd cost to have him wire it up or to have him watch me wire it up so I don't get hurt. I really want to wire it myself, but I don't know if he'd let me do that.

The idea is to run the wires to the transformer, and on the output side of the transformer, where I have true one phase 240VAC, run that to a new breaker panel. Then just tie into that sub-panel whenever I need true 240VAC. At this point, I think I can purchase that connector you linked me too....

But I still need help making sure I understand the transformer correctly. X2 and X3 get tied together I think. X1 would be my 240VAC, X4 would be my Neutral. On the primary, H1 gets tied to H7, and H10 to H4, but where do I tie in the mains? The two 120VACs from my double pole breaker?

H1 and H7 and then the other to H10 and H4? Or do I tie the mains to H5 and H6 or is that a big NO!

[Spork Schivago]

Re: Need help wiring up 240VAC.

Also, with that connector Stj, seeing how I'm probably going for the transformer, do I still use the same connector, the 2P+E? Once I have true 1-phase 240VAC, would I need a different connector? I don't think so, because the plug itself says 2P+E, and the PDU is made for 1-phase 240VAC, not 120-0-120 split-phase.

If anyone has any ideas how I tie into that transformer, please let me know, or if they can provide feedback on the idea of adding a subpanel, where the transformer is in between my mains panel, and the subpanel, please let me know. Everyone's seemed to have gone quiet. That scares me!

[stj]

Re: Need help wiring up 240VAC.

same connector.
2P+E simply means 2 poles(contacts) + Earth.
it's a physical description, not an electrical one.

[budm]

Re: Need help wiring up 240VAC.

240V:240V transformer wiring.
You must consult your electricians as how the GND must be done plust other requirements to meet the code.

[Spork Schivago]

Re: Need help wiring up 240VAC.

I ran a test. Despite what the HPE techs said, some of the people on EEVBlog where correct. I wired one of the 1400 watt PSUs up to one of my NEMA L6-30P's and plugged it in. Fired right up.

Even though I've installed the PDU, we still have the original box and packing material (which must be kept if we're not sending it back for warranty purposes). I'm hoping I can use the HPE techs said the PSUs wouldn't work with the American 120-0-120V split-phase as leverage if they give me any shit about sending it back.

But I'm going to attempt to do what Per Hansson said and send that bitch back and purchase a couple of the P9S13As.

[Spork Schivago]

Re: Need help wiring up 240VAC.

240V:240V transformer wiring.
You must consult your electricians as how the GND must be done plust other requirements to meet the code.

Wow, thank you. You are truly an amazing person Budm. I'm almost tempted to just keep the PDU I have and buy the transformer because you went through all that work. Personally, I like this PDU with the connector on it. I've never been big on the NEMA L6-30R's and NEMA L6-30P's, especially the twist-and-locks. Maybe it's because I've been buying them at Home Depot and Lowes and I can get higher quality ones somewheres else? But they always feel real chinsee to me. Even when I plug in the plug and twist it, it always feels like something is going to break off.

[stj]

Re: Need help wiring up 240VAC.

keep in mind at 120v you need to try to keep the load on the 2 lines pretty balanced.
if not it's anybody's guess what your electric meter will think!