Purchasing European Voltage Transformer Questions

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wehaveplans

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We are building a data center and we would like to take advantage of new PDU generation that removes a secondary stage of transformation allowing for 40% less gear. It's a simple concept, our gear is rated 200v to 250v single phase so we just need the voltage output to be in that range. 380v, 400v, or 415v (three phase) run in a line to neutral configuration result in a single phase output of 220v, 230v, or 240v respectively. The PUD is providing us with 5mVa @ 13.2kV. Ideally we would use a 13.2kV / 415Y transformer. A 13.2kV / 380Y and 13.2kV / 400Y transformer would also work.

We have sourced a few used option in the UK and Australia, we are in talks with a company in the USA that will charge us way too much to custom build one, and we have a list of 5 manufactures in China that can build us essentially what ever we need. While I know the UK/Australia/USA companies will be very straight forward, the cost savings and custom flexibility of the Chinese made unit looks very attractive. The company has CE certifications (and a few other that do not apply to the USA), but they do not have a UL listing. From what I have researched, we can have an NTRL work with us though the steps from engineering, to manufacturing, to approving it for just the site we install it on.

Can anyone provide me with any reasons I shouldn't start working towards this? Does anyone have any horror stories of what went wrong on similar projects so I can understand mistakes that were made?

Please keep in mind, the Chinese manufactures we found currently work with a customer of ours in Canada. We know their products are solid. Product quality isn't the concern here, it's the codes and inspectors.
 
There is a CSE webinar that mentioned this.
 

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wehaveplans said:
We are building a data center and we would like to take advantage of new PDU generation that removes a secondary stage of transformation allowing for 40% less gear. It's a simple concept, our gear is rated 200v to 250v single phase so we just need the voltage output to be in that range. 380v, 400v, or 415v (three phase) run in a line to neutral configuration result in a single phase output of 220v, 230v, or 240v respectively. The PUD is providing us with 5mVa @ 13.2kV. Ideally we would use a 13.2kV / 415Y transformer. A 13.2kV / 380Y and 13.2kV / 400Y transformer would also work.

We have sourced a few used option in the UK and Australia, we are in talks with a company in the USA that will charge us way too much to custom build one, and we have a list of 5 manufactures in China that can build us essentially what ever we need. While I know the UK/Australia/USA companies will be very straight forward, the cost savings and custom flexibility of the Chinese made unit looks very attractive. The company has CE certifications (and a few other that do not apply to the USA), but they do not have a UL listing. From what I have researched, we can have an NTRL work with us though the steps from engineering, to manufacturing, to approving it for just the site we install it on.

Can anyone provide me with any reasons I shouldn't start working towards this? Does anyone have any horror stories of what went wrong on similar projects so I can understand mistakes that were made?

Please keep in mind, the Chinese manufactures we found currently work with a customer of ours in Canada. We know their products are solid. Product quality isn't the concern here, it's the codes and inspectors.
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13.2kV is not standard in UK, 11kV is. In fact, I'm not sure if any European country uses 13.2kV so you maybe need to watch that. The LV side in UK was changed from 415V to 400V and in other European countries from 380V to 400V to harmonise voltages Europe wide.
 
Besoeker2 said:
13.2kV is not standard in UK, 11kV is. In fact, I'm not sure if any European country uses 13.2kV so you maybe need to watch that. The LV side in UK was changed from 415V to 400V and in other European countries from 380V to 400V to harmonise voltages Europe wide.
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That's good to note, potentially we should go straight to 400v as to match the rest of the EU's practice. Having our units customer manufactured allows for us to design for 13.2kV/400Y. My main concern isn't enginnering, it's being one of the horror stories where inspectors shut the site down.
 
Any of these not workable?

240 delta.
You would have to use L-L method but leaves you some 120v power for other use.

240 corner ground. You have L-N for two of the phases and L-L for one.

208Y/120. You're getting MV service rather than so get a MV to 208/120 substation?
You could also get a MV to 480/277 substation and feed air handling and lighting and run them along side. Not 480 to 208 in series.
 
Electric-Light said:
Any of these not workable?

240 delta.
You would have to use L-L method but leaves you some 120v power for other use.

240 corner ground. You have L-N for two of the phases and L-L for one.

208Y/120. You're getting MV service rather than so get a MV to 208/120 substation?
You could also get a MV to 480/277 substation and feed air handling and lighting and run them along side. Not 480 to 208 in series.
Click to expand...

None of our gear will operate bellow 200v; even desktops, lights, printers, etc.

We can get 13.2kV to 208Y transformers in a very short notice, the issue is the added cost and massive loss in efficiency due to 208 in a data center.

Our current configuration is 208Y L-L to our PDU's. What's hard to wrap your head around is the density of our new data center we have designed. We want to use 50amp circuits at 400v. At 208Y everything has to be double sized to provide the same capacity output. Double the quantity of breakers, line sizes, receptacles, PDU's etc.
 
wehaveplans said:
None of our gear will operate bellow 200v; even desktops, lights, printers, etc.

We can get 13.2kV to 208Y transformers in a very short notice, the issue is the added cost and massive loss in efficiency due to 208 in a data center.

Our current configuration is 208Y L-L to our PDU's. What's hard to wrap your head around is the density of our new data center we have designed. We want to use 50amp circuits at 400v. At 208Y everything has to be double sized to provide the same capacity output. Double the quantity of breakers, line sizes, receptacles, PDU's etc.
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You didn't read anything I wrote.
240 delta gives you 240 phase to phase and you wire things up phase to phase. I am saying that on two of the phases, 120v is available as well, that meaning 120 and 240, usable simultaneously. You will inevitably have something you will need plug-ins for.

IT machine things are designed for this. Many EU countries run L-N 230v. US is L-L 208v.

wehaveplans said:
Product quality isn't the concern here, it's the codes and inspectors.
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Perhaps you wouldn't have to worry if you're not planning on doing something you're not supposed to do by our codes. Can't really blame 'em if they were to have problems with some stuff you had shipped from China and decide to hook it up to 13.2kV because you feel the quality is fine, but not whether it meets UL requirements

wehaveplans said:
None of our gear will operate bellow 200v; even desktops, lights, printers, etc.
Click to expand...
I am not sure about the legality of having foreign voltage standard for general purpose stuff here around the office, such as a desktop PC.
 
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Electric-Light said:
You didn't read anything I wrote.
240 delta gives you 240 phase to phase and you wire things up phase to phase. I am saying that on two of the phases, 120v is available as well, that meaning 120 and 240, usable simultaneously. You will inevitably have something you will need plug-ins for.

IT machine things are designed for this. Many EU countries run L-N 230v. US is L-L 208v.
Click to expand...

I'm an engineer, but not an electrical engineer, so I apologize if I'm missing something.


In order to receive 240v you would need multiple 480v/240Y transformers, which are expensive and add an additional step of transformation. Mathmatically, I don't see a PDU wiring configuration for 480 to 240 as the single phase of 480Y is 277v. Please correct me if I'm wrong on this.


We could have a custom 13.2kV/240Y transformer made, but if we were to go this route it would be more benneficial to have a 400v transformer made.


Using 400v would save us around $200,000 in this system so we are heavily leaning towards it.
 
wehaveplans said:
I'm an engineer, but not an electrical engineer, so I apologize if I'm missing something.


In order to receive 240v you would need multiple 480v/240Y transformers, which are expensive and add an additional step of transformation. Mathmatically, I don't see a PDU wiring configuration for 480 to 240 as the single phase of 480Y is 277v. Please correct me if I'm wrong on this.
Click to expand...

These are all standard utilization voltages here.
480Y/277
240 "high leg" delta
240 corner ground
208Y/120


If you're going to use 415Y/240 in the US you would have to use 480v equipment and panels. Breakers rated for 240 or 277 v to ground just as if you were running 277v lighting circuits. Everything has to be proper by the NEC and using materials UL listed for the purpose you're intending to use it for. Just out of curiosity, who's going to be hooking up all this or the 13.2kV transformer? :eek:hmy:



We could have a custom 13.2kV/240Y transformer made, but if we were to go this route it would be more benneficial to have a 400v transformer made.
Using 400v would save us around $200,000 in this system so we are heavily leaning towards it.
Click to expand...
It would have to have proper NRTL listings and appropriate specifications for use in the US. A fault on 13.2kV could cause an outage to other people on the gird and they're not going to want people plugging whatever they want to it.
 
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Electric-Light said:
These are all standard utilization voltages here.
480Y/277
240 "high leg" delta
240 corner ground
208Y/120


If you're going to use 415/240 in the US you would have to use 480v equipment and panels. Breakers rated for 240 or 277 v to ground just as if you were running 277v lighting circuits. Everything has to be proper by the NEC and using materials UL listed for the purpose you're intending to use it for. Just out of curiosity, who's going to be hooking up all this or the 13.2kV transformer? :eek:hmy:
Click to expand...

Unless I'm missing something (which is very possible), 240 delta would require step down transformers from 480, or we would still need to install custom made equipment. Since this is a 5,000 kVa facility, any additional transformation steps would add significant additional time and materials.

The entire distribution system though the whole facility would be 415v, all they way down to the receptacles where the PDUs plug in. This will allow us much higher densities while using smaller sized breakers and wire. The PDU's are wired to provide outlets with 240v single phase. See here for reference: https://www.tripplite.com/25.2kw-3-...15v-input-6ft-cord-0u-vertical~PDU3XVSR6G60A/

This design is quickly becoming the standard for new data center construction due to the incredible cost savings and efficiency improvements. My research started after walking though a Google data center. You can see there design here: https://www.youtube.com/watch?v=XZmGGAbHqa0&t=177s

You can see in the video: power is fed onto the floor at 415v, tapped into the busway, the busway has tap-offs into a power distribution board with GFI receptacles, the PDU's are plugged in resulting in access to 25kW of 240v single phase per rack. Extremely efficient, high density, and less transformation systems required.

We have everything sourced and ready for order next week other than the custom transformer. I need to make sure there isn't anything wrong with installing a CE certified transformer in the USA by having a NTRL agent assist us with the process.
 
wehaveplans said:
We have everything sourced and ready for order next week other than the custom transformer. I need to make sure there isn't anything wrong with installing a CE certified transformer in the USA by having a NTRL agent assist us with the process.
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I have been involved with installations that have transformers sourced from around the world, including China and Russia, so I know they can be approved by some authority.

415Y/240V data centers are not uncommon in the US.
I do not understand why you would be having trouble locating a vendor that can provide a NRTL listed transformer?

Are you designing the complete facility? It is unlikely that your facility will be able to be constructed without using a US standard voltage for the general premises wiring.
 
jim dungar said:
I have been involved with installations that have transformers sourced from around the world, including China and Russia, so I know they can be approved by some authority.

415Y/240V data centers are not uncommon in the US.
I do not understand why you would be having trouble locating a vendor that can provide a NRTL listed transformer?

Are you designing the complete facility? It is unlikely that your facility will be able to be constructed without using a US standard voltage for the general premises wiring.
Click to expand...
We have found a few very, very expensive companies that can supply these transformers locally. We were put into contact with a few reputable manufactures in China by another data center in Canada who is using similar designs. Even after shipping, they are 30% cheaper and 1/2 the production time. I'm simply trying to learn about any headaches or costs that may come from doing the NRTL process ourselves.

We are designing the facility completely and then handing off what we came up with to engineers for adjustments / approvals. The utility told us they are providing us with 5000 kVa @ 13.2kV and we can do what ever we wish to do after the demarcation, as long as it follows any and all codes. I have asked them if what we are planning on doing is acceptable multiple times and it's always the same response: "The customer with customer owned equipment is responsible to meet all NEC and L&I state regulations. We have no requirements after the demarcation point. "
 
wehaveplans said:
Even after shipping, they are 30% cheaper and 1/2 the production time. I'm simply trying to learn about any headaches or costs that may come from doing the NRTL process ourselves.
Click to expand...

Remember, 'You don't get what you didn't pay for'.

NRTL listing can be expensive and time consuming.
Utilities have nothing to do with premises wiring as you have found out. Have you made contact with your Authority Having Jurisdiction (these are usually the groups that issue permits)?
 
wehaveplans said:
Unless I'm missing something (which is very possible), 240 delta would require step down transformers from 480, or we would still need to install custom made equipment. Since this is a 5,000 kVa facility, any additional transformation steps would add significant additional time and materials.
Click to expand...
I'm saying, step down 13.2kVA to 240 delta directly with a pair of 2.5MVA transformers or 13.2kV to 480y/277v and use server power boxes that takes 277v, as Google did.

Since you're so concerned with efficiency of double transformation, are you certain that a used(older standards...) 50Hz optimized Euro or Chiinese made to order stuff wouldn't have a lower efficiency than a brand new off the shelf transformer to get 13.2kV to 480v and stepped down to 415v with an auto-transformer if you absolutely had to? The autotransformer only transforms the difference, not the entire load and it will be a lot smaller than the first transformer. It is used for a relatively small voltage change like this one. In your close, only 700kVA


You can see in the video: power is fed onto the floor at 415v, tapped into the busway, the busway has tap-offs into a power distribution board with GFI receptacles, the PDU's are plugged in resulting in access to 25kW of 240v single phase per rack. Extremely efficient, high density, and less transformation systems required.
Click to expand...
but it isn't. They're using 480/277v with 277v power supplies instead of custom made mini substation.
 
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A few points to conciser.
The British Standard is a 50 htz system not 60 htz.
Panels, disconnects, circuit breakers may need to be rated 277/480v or 600v not 250v.

I see a lot of electronics from around the world providing power to shows like CES, SEMA, NBA, JCK, MAGIC, FABTECH, CONEXPO, etc
It seems odd that everything including printers is only 200-250v.
The trend is 100-250v 50/60 htz with electronics so it can be manufactured to be used on most systems with only a different cord (or plug adapter for travelers).
When they want 200-250v they get 208v from 120/208v Y. Anything other than 120, 208, 277, or 480 gets a bulk boost transformer or their on generator outside.

I remember one German company that wanted 230v for their 3 receptacles at an electronics show. Ran 480v to their transformer to get their 230/400v in addition to all the other 120/208v for their panels. Had to fix the connections in their transformer. Got their exact desired voltage to their EU receptacles. Day before the show they ask me for an adapter to convert the EU receptacle so they could plug in their device made with a standard 120v USA cord cap. The device worked on 100-250v. All that work. Wouldn't doubt if it cost them $10,000 in labor, power charges, and the cost of the transformer shipped from Europe. All they needed was an extension cord off their other 120v panels.
 
active1 said:
A few points to conciser.
The British Standard is a 50 htz system not 60 htz.
Panels, disconnects, circuit breakers may need to be rated 277/480v or 600v not 250v.
Click to expand...
It's common in UK for fault make/load break switches to be rated at 660Vac. And sometimes 690Vac.
 
jim dungar said:
Remember, 'You don't get what you didn't pay for'.

NRTL listing can be expensive and time consuming.
Utilities have nothing to do with premises wiring as you have found out. Have you made contact with your Authority Having Jurisdiction (these are usually the groups that issue permits)?
Click to expand...
One of the USA transformer manufactures suggested that we tap the primary voltage up to 14.49kv so that we result in 440/252 on the secondary. Is there anything wrong with doing this?


The server power supplies are rated at 200 to 240v. Looking further into their design, their AC/DC converter is rated 176v to 264v so 252v will work. I assume the 200v to 240v is just an engineers way to mark them for a 208v environment. Furthermore, they have three under/over voltage/current devices in them. We have tried to run these on 120v before and they will not even turn on. I've seen these be over powered and they simply kick off.
 
wehaveplans said:
We have found a few very, very expensive companies that can supply these transformers locally. We were put into contact with a few reputable manufactures in China by another data center in Canada who is using similar designs. Even after shipping, they are 30% cheaper and 1/2 the production time. I'm simply trying to learn about any headaches or costs that may come from doing the NRTL process ourselves.

We are designing the facility completely and then handing off what we came up with to engineers for adjustments / approvals. The utility told us they are providing us with 5000 kVa @ 13.2kV and we can do what ever we wish to do after the demarcation, as long as it follows any and all codes. I have asked them if what we are planning on doing is acceptable multiple times and it's always the same response: "The customer with customer owned equipment is responsible to meet all NEC and L&I state regulations. We have no requirements after the demarcation point. "
Click to expand...

You are not an ee but are designing a large complex electrical system?
does not sound like a sound practice


try ABB
I would not skimp on this xfmr
what % of total project cost is it?
the bldg, pdu's, install, design docs, etc
moot

from China: warranty? Service?

where does the ups fit into this?
 
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