transformers and data centers/com rooms

[HighLeg77]

would like to hear all opinions/facts on why placing a typical step down transformer, let say a 480v 3 wire to 120/208v 4 wire, 15 to 45kva xfrmer in a communications/data center is a bad idea. ive read about harmonics and wave forms to magnetic fields. computer screens and so on. read about if a transformer has a melt down and all data in computers are lost. would like the low down on why is safer to place else where. and how much further away is needed. not that i think its a good idea or anything. ive always kept them far away from such electronics and so on. having a conflict between engineers and architects on job im running and no one seems to wanna budge, leaving it to my decision. thanks, think i posted this is the wrong section. could a mod please move for me... thanxs/.

 

[iwire]

Many PDUs include transformers and are designed to be located in the room with the equipment.

 

[BryanMD]

would like to hear all opinions/facts on why.... sniiiiiiiiiiiiiiiiiiiip! ...having a conflict between engineers and architects on job i'm running and no one seems to wanna budge...

Keep re-sending the RFI's; and just refuse delivery on the invitation to their party.

In the absence of an an architect and/or an engineer on the job then you would be getting the design-build bucks that come with making those design choices. But that isn't the case... is it?

 

[cschmid]

are we using a plain transformer or PDU like Bob showed?? An regular transformer setting on floor or hung from ceiling would be frowned on. The ones I have done we hang the transformer in the electrical vault or an adjacent room and pipe it in to the data center. Most places I have worked on do not want the expense of a liberty uni like bob showed.

 

[HighLeg77]

your right bryan. i dont make the build/design bucks. and no they arn't on the jobsite. they are arguing back and forth looking at drawings. the architect for astectits and looks and keeping the data center equipment in the same room. the ee for my point of view and also clearences. the facility has pdu's in other rooms, but no xfrmers inside. just panelboards in cabinets really ontop of the raised floor. the xfrmers are located in another ups room. and yes were talking plain xfrmers, not the combination of pdu/xfrmer. setting the xfrmer in the floor right beside the new ups's and panelboards. less than 7 feet away from the com racks.

 

[Pierre C Belarge]

This is not a code issue.
But...
It can be a design issue. If the EE or Architect are designing it a certain way, I guess you may not have much of a choice.

Where did it show them on the print?

 

[jeremysterling]

I've seen the plain-jane transformers on data floors and I don't see a reason not to have them there.

Last month I went on a trouble call to a data center where two 75kVA and two 112.5kVA tranny's were on the roof (with rain shields but no lightning protection). If my choices were data floor or roof, I'd lean toward data floor location.

 

[Power Tech]

I would keep the heat box out of the climate controlled area if possible.

 

[jeremysterling]

I've seen the plain-jane transformers on data floors and I don't see a reason not to have them there.

I would keep the heat box out of the climate controlled area if possible.

Doh! :roll:

 

[HighLeg77]

yer right, not a code issue at all. definatly a design issue. it shows 1 30kva in the com room on the floor. feeding 2 seperate 15 kva ups's then to 2 100amp panelboards. and yer definatly right....heatboxes. those com rooms have thier own air/crac units for cooling. and they keep them very cool.

 

[__dan]

Well ...

Well ...

Well ... You asked for opinions

For the transformer, first thing I would look for is if they spec'd "K" rated transformers. The K rating means the transformers are built to handle the added heat of high harmonic loads. I'd look at where they spec'd the run of the GEC, what they chose as the point of attachment to a grounding electrode. Properly wired, EMF outside of the steel enclosures should be zero.

Properly chosen, the transformer is dry type and has very low chance of meltdown. If you have the footprint for it, running it in a forced cooled space near the load is good for it.

The issues surrounding the UPS placement are far more tight. The UPS could be 75% to 85% efficient which means lots more heat. They require lots more supervision and maintenance, the batteries and capacitors are wear items. Depending on the battery type, the batteries could cause the room to have a lot of additional regulatory requirements. Generally, batteries in the data floor space is a bad idea, transformers on the data floors are OK.

As a variable, I would look at running the UPS at 480 volt delta in and out upstream of the transformer and outside of the data room. Bringing 480 volt delta to the data room with transformer and panelboards downstream of the UPS.

A change like this would have to be made if the KVA were a lot larger.

 

[dbuckley]

I'm very happy with dry K rated transformers in computer rooms.

And I'm with Dan; put the UPS outside the computer room, and keep the voltages up, so use a 480v UPS, and make yourtranny a delta/wye, not wye/wye. Then your UPS only needs three wire in and out (no neutral) (or a minumum neutral if a neutral required) as the stepdown tranny is delta/wye - could save the customer a load of coin on that depending on site layout.

 

[HighLeg77]

the transformers will definalty be k rated. 200% neutral. if not k they will be mignating.. i know i spelled that wrong. here lately ee has been on a kick of spec'ing those mignating xfrmers. let me ammend my orginal thoughts. the questions ive been asking are for communications rooms as well as raised floor data centers in general. just for future installs. the specific installation im having trouble with and asking about is a plain and simple room. about 16x25 in dimention. false 2x4 tile celiing with 2x4 lights. vct tile on the concrete floor. just a communication room. with a communication rack offset in the middle, with servers and punchboards. the ups's have to be the 208/120 4 wire with 200% neutral, as thier trying cut cost and reuse equipment from a different facility. im starting to lean towards there not being as much a issue as before. just make sure the xfrmer is well grounded, maybe to bld steel and cold water as well, along with the primary and secondary grounds. probally hang xfrmer in the elect room thou its only 40 feet away. but the ups's will have to go in that communications room. no place else for sure. any other words id love to hear, considerations, concerns. thanks again to all & for yer time. hector/.

 

[macmikeman]

I'm not kidding around here gang, (honest) there is usually at least a few brainiacs who work in those computer rooms doing database managment and tweaking and so forth. The sound of the ac system is distracting enough for them let alone a tranny humming all day long. This is also a big reason that the xfmr is located out of the room. But in an access controlled high security computer room, too bad for you Poindexter, the transformer goes right here also...

 

[skeshesh]

The engineer may be nitpicking here if you have a proper k-rated transformer. If he wants to go a step further why doesnt he recommend harmonic filters? I guess I've seen very specific situations where harmonic studies have been done by highly knowledgable engineers and based on the results some abnormal design's been done - for a regular data room with a couple of racks I dont see the issue unless, again, you're talking about a really sophisticated communication center with big data rooms on each floor, etc. Also follow the recommendations for the UPS 3W input that dbuckley posted - good stuff.

 

[steve66]

I'm not kidding around here gang, (honest) there is usually at least a few brainiacs who work in those computer rooms doing database managment and tweaking and so forth. The sound of the ac system is distracting enough for them let alone a tranny humming all day long. This is also a big reason that the xfmr is located out of the room. But in an access controlled high security computer room, too bad for you Poindexter, the transformer goes right here also...

They will never hear the transformer hum over the HVAC, and all those small fans running in all the rackmounted stuff.


Steve