Electronics > Beginners
How to wire up a 240VAC receptacle
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james_s:
That's surprising with the trends these days, even medium sized companies are outsourcing their server needs to cloud based suppliers. One of the places I worked years ago we had our own servers but leased a rack at a collocation center a few blocks away. They provided the power, cooling and data, we racked and maintained our hardware. 
Spork Schivago:

--- Quote from: C on May 16, 2018, 09:41:40 pm ---
Looks like you like to ignore simple facts.

In the USA the standard electrical outlet is 110-120 volts 60hz.

All 220-240 volt stuff uses different connectors. Because of the difference people take more care.

Think of how many people in the USA have used computer power cords. For the USA the end that connects to a computer is 115volts. For a lot of the world that is 220volts but not in USA.

So now you have people seeing the computer end thinking 115volts and connecting an extension cord to your PDU, but that is not 115 volts. A part of safe is knowing what to expect.
So what is a safe European standard is not as safe in the USA due to common thought.

The added transformer is creating a safe NON-USA standard in addition to wasting power. That transformer will get hot, and that is a waste of power. 

One thing you might like to know is that 220 volt 60hz is more dangerous then 220 volt 50hz. The 60hz has a greater chance of messing up your heart beat then 50hz.

If you want real safe 220 volts using a USA split phase( 220 Volts with a neutral center tap) you use a four wire connection. The forth connection the safety ground.
Unlike the rest of the world USA 220 volt equipment often has some 115 volt loads.

C

--- End quote ---

We need 240VAC, again, for the server, not 220VAC, although it would run on 220VAC.   Most of our equipment is NOT from the USA.   The cords to power these devices are NOT what you find with a NORMAL USA bought PC, so I highly doubt anyone who is allowed to be around the rack will try plugging anything into the PDU.    I mean, simple fact, strangers aren't going to be down here, and if they are, they're breaking the law.   Eventually, we have to worry about my daughter, but that's a long ways away, and even then, she cannot physically get into the rack to plug anything into the PDU.   Ohm's law shows us if we double the volts, we cut the current draw in half.   200v * 2 amp = 400 watts.   20 amp * 20v = 400 watts.    I think I'd rather get shocked, if I had to get shocked, at the 200v, 2 amp, rather than the 20 amp.

I have no idea how anyone is going to plug any cords into the PDU, I don't know what you think the inputs look like, but you physically cannot take a normal PC cord and plug it into the PDU.   You need special cords....most of our energy hungry equipment is designed to run off 240VAC, but most of it can go down to 100VAC.   I mean, we have some American made workstations, but they're not going into the rack at all, and aren't being powered by this PDU.   A lot of stuff came from Germany.   There's usually no switch on these pieces of equipment to flip.   They say 100VAC - 240VAC.

I mentioned in a previous post that security was our responsibility and we get audited, where some people from some companies come in and check to make sure everything is up to their standard.   We get a report on what needs to change, if anything, and it's our responsibility to change what they list.   Once we wire up the 15kVA transformer (or higher someone to wire it up for us), we'll have to have yet another one of those pesky audits.

There's security in place.  Maybe you can take comfort in knowing that currently, no one who is specifically supposed allowed in the datacenter can get into the datacenter without doing a lot of illegal work?   This isn't a playroom.   The idea is though, we do our own thing once these contracts are up, and hopefully, later on in life, our daughter takes interest.   If not, that's okay, we'll love and accept her no matter what.   That's years down the road before we burn that bridge though.

Heck, do you know how hard it was to say no to the three phase installation?   We were talking over 50,000$ and almost went for it, because then we can purchase stuff that's a bit more suited to our task at hand.   I feel better having a PDU hooked up with a backup sitting on the shelf in case one shits the bed, rather than daisy chaining a whole bunch to try and get my systems running.
Spork Schivago:

--- Quote from: james_s on May 16, 2018, 11:04:06 pm ---That's surprising with the trends these days, even medium sized companies are outsourcing their server needs to cloud based suppliers. One of the places I worked years ago we had our own servers but leased a rack at a collocation center a few blocks away. They provided the power, cooling and data, we racked and maintained our hardware.

--- End quote ---

We got something similar going here.   One of the companies we can see from our house, but they're really big.   They try to use resources in the community, and have helped my city a lot.   Here, we outsource to Microsoft for some of our needs.   We use a CSP license and have Enterprise E3 editions running.   Our exchange server is on a Microsoft server, our active directory is on a Microsoft server.   Heck, even our conference calls go through Microsoft!   However, there's stuff we have to make sure doesn't get uploaded to the Microsoft server or any of our VPSes.   Stuff that has to stay local.   We have a fancy switch for that, that has routing capabilities and we segregate / isolate different networks, some with access to the outside world, some without.   That way, we keep the residential stuff on the residential side, the business machines that are supposed to have internet access can reach our gateway, and the machines that are not supposed to, cannot.   It was a real pain to setup originally.   I've always been a Cisco man and configuring a Cisco switch is a lot different than configuring an HPE switch.   Lot of new info to learn and little bits of sleep, but we're slowing down now.   Slowly getting there.   I'd say the main contract, I wouldn't have it if it wasn't for some connections I have to have either worked at the company or currently working at the company.   Kinda got lucky there.

One thing, it seems, people keep forgetting, our servers.   We had two options.   3-phase, or 1-phase 240VAC.   I think it was Mr. Crowley who pointed out that PDUs only push out what they're fed in.   You feed them 240VAC split-phase, they put out 240VAC split-phase.   You feed them 240VAC 1-phase, they put out 240VAC 1-phase.    So I'm wondering how the people who keep recommending the 120VAC - 0 - 120VAC solutions have come up with a way of powering the servers.   I think we'd be back to an unsafe environment to the same unsafe environment we'd be in now if we ran 120VAC and 120VAC to our PDU.
Spork Schivago:
I stand corrected.   These power supplies are the only option for our servers.   There are no three-phase ones like I was thinking.   They only make the 1400 watt in one style that's compatible with our servers.
Richard Crowley:
Note that "120VAC - 0 - 120VAC" is the same thing as "split-phase".

None of the HPE PDU are designed to handle split-phase.  They are all designed for schemes where Neutral = Ground.

If you connect any of those HPE PDU things to domestic split-phase where Neutral = 120VAC, you are setting up a situation that is dangerous for both equipment and people.

That is why a transformer is need to convert 120-0-120 ("split-phase")  into 240-0 ("single-phase")
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