Largest sealed Dry Type you can get?
Largest sealed Dry Type you can get?
(OP)
Hello,
I am looking for an outdoor rated 2.5MVA stepdown XFMR from 4kV to 600V. This is going at a mine site in the North and the environment is dusty. I am trying to avoid oil type XFMRS if I can. It's a not a big deal, but I am curious, what's the largest dry type I can get that is "sealed" from the outside environment? Transformers need to disapate heat, but I was wondering does a 2.5MVA dry type with no vents exist on the market?
Secondly, does anyone have a hard copy of "What we need to know about dry-type transformers" from Electrical Apparatus Magazine, Oct 2002 by Nailen, Richard L?
There is an online version, but the figures are missing. Can someone please scan the article? It's a good read.
http ://findart icles.com/ p/articles /mi_qa3726 /is_200210 /ai_n91328 56/?tag=co ntent;col1
Thanks
Majesus
I am looking for an outdoor rated 2.5MVA stepdown XFMR from 4kV to 600V. This is going at a mine site in the North and the environment is dusty. I am trying to avoid oil type XFMRS if I can. It's a not a big deal, but I am curious, what's the largest dry type I can get that is "sealed" from the outside environment? Transformers need to disapate heat, but I was wondering does a 2.5MVA dry type with no vents exist on the market?
Secondly, does anyone have a hard copy of "What we need to know about dry-type transformers" from Electrical Apparatus Magazine, Oct 2002 by Nailen, Richard L?
There is an online version, but the figures are missing. Can someone please scan the article? It's a good read.
http
Thanks
Majesus






RE: Largest sealed Dry Type you can get?
RE: Largest sealed Dry Type you can get?
RE: Largest sealed Dry Type you can get?
Cast coils is the key ;o)
Cheers,
Majesus
RE: Largest sealed Dry Type you can get?
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If we learn from our mistakes I'm getting a great education!
RE: Largest sealed Dry Type you can get?
RE: Largest sealed Dry Type you can get?
I would have no problem using these outside, but dirt and dust will still get inside the enclosure, just like any other dry-type.
David Castor
www.cvoes.com
RE: Largest sealed Dry Type you can get?
If you do not want a mineral oil cooled unit, then have you considered MIDEL? This is a non flammable biodegradable liquid. Here in UK it is available and quite useful, given the increasing views on the environment and safety aspects. I am not sure if this is availabe or acceptable in all countries.
RE: Largest sealed Dry Type you can get?
Interesting note... I did some work on an ABB unit with the BIOTEMP fluid about a month ago at a wind farm in South Dakota. The unit was not yet energized. The "oil" was frozen solid. Per ABB, it was deemed safe to energize the unit with full thermal and dielectric properties.
RE: Largest sealed Dry Type you can get?
Newcastle and the bits further up. As distinct from Gateshead, which is clearly in "the South".
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If we learn from our mistakes I'm getting a great education!
RE: Largest sealed Dry Type you can get?
We have the same type of biodegradable oil. For example, Cooper offers a product called FM3
h
It's not flammable, but fire resistant. Midel is also fire resistant. It sill is flammable just at a high fire point. (>300°C)
DPC, so at 2.5MVA, vents are necessary. I am looking for it all. Dry type with no vents, just wishful thinking.
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Just a note, it's not a big deal to go with oil. I'm just exploring available options. We place an oil containment around the XFMR and move on.
Cheers,
Majesus
RE: Largest sealed Dry Type you can get?
Are you trying to avoid the typically massive Ex 'd' enclosures? Based on the former coal miners I have worked with you probably don't want to give them anything remotely breakable.
Have you considered a sand-filled design which would have better heat rejection to ambient than an air-filled enclosure?
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If we learn from our mistakes I'm getting a great education!
RE: Largest sealed Dry Type you can get?
David Castor
www.cvoes.com
RE: Largest sealed Dry Type you can get?
Note: GE and ABB came back this afternoon with details. Largest they can go that is dry type, sealed is 500kVA.
Thanks,
Majesus
RE: Largest sealed Dry Type you can get?
RE: Largest sealed Dry Type you can get?
http://www.eamagazine.com/
David Castor
www.cvoes.com
RE: Largest sealed Dry Type you can get?
All our coil are factory PD tested, then get a PF/DF, TTR, IR , exication test and winding resistance before shipment.
RE: Largest sealed Dry Type you can get?
RE: Largest sealed Dry Type you can get?
RE: Largest sealed Dry Type you can get?
-Y