Electrical Switch Gears & Assembly

Use a thermal imaging camera.

You need to hire an intelligent engineer to guide you at your sites.

Without one you will continue to fail.

90°K is equal to -185°C or -297°F.

Get a competent electrician to trouble shoot your problems.

Asking an anonymous forum to do your work for you will only end in more failure.

Could it be due to eddy current losses ? Unlikely, but you need to rule out.

How are the conductors of various phases arrayed with respect to the steel supports?

90k? Is this the thermal color temperature?

If so, you are doing some pretty far-out work there!

What equipment did you use to determine the temperature?

Please try to use units which are more readily understood, such as Fahrenheit or Celsius. If you have used infrared camera to determine those temperatures, capture an image and if possible post it here.

Your difference in temperature between your aluminum busbar and the MS (steel?) supports is understandable. The aluminum will dissipate more evenly which should reduce hotspotting.

Do you see any hotspots?

For conventional Busduct for any current rating above 2500A it will be advisable to provide non magnetic enclosure to restrict the Eddy Current circulation on the enclosure.Also the magnetic path of the supports fixing brackets to be broken, then only Eddy current circulation can be minimised.Also for heavy duty busducts say 4000 A and above Aluminum Enclosure would be preferable.

I was a Bus duct manufacturer from 1981 to 2006, during my days I used provide Sheet steel enclosure for busduct upto 4000 A ,but break the magnetic path by providing stain less steel strips and using stainless steel hardware.For above 4000 A I used give Aluminum Alloy enclosure.

In your case it is sandwich Busduct, the temperature rise problems are noticed in many sites, these have to be addressed by the sandwich busduct manufacturer.

I had raised these issues in many forums but no convincing replies were given by the manufacturer, but many Projects are being installed with Sandwich Busducts

I am assuming you mean 90 deg C and 55 deg C temperature rise above ambient.

Is this something a professional switchboard manufacturer has supplied or made for you or something someone has just designed or assembled that (shall we say) is not experienced in electrical bus work design and assembly?

Are the other sites bus work of the same construction but don't have the same problem? If so, what's different?

Can you post a photo of the bus work area in question?

& when pstg ur FU info, pls refrain from using 2LAs and 3LAs that we m/mnot understd, i.e. "MS" etc.

Like "etc", you mean?

In partial defense of the OP.... ⁰K means Degrees Kelvin which is the correct temperature scale for scientific and engineering fora (as opposed to 'forums' quite often used, but is somewhat wrong) However. it starts from Absolute Zero, which is -273.15⁰C. So technically, he should have mentioned 363.15⁰K if he wanted to say 90⁰C. Fahrenheit is cumbersome for us who use Celsius/Centigrade.

'MS', i thought, is a universal acronym for mild steel, but i see that it is not.

i am all for elimination of acronyms on CR4. Except things like RTFM, ROTFLMAO and so on

Seriously, what are the chances this is an application using 2200A bus work (and aluminium at that) operating at cryogenic temperature levels?

Negligible I say, surely the op means temperature rise above ambient.

In our engineering courses, we are taught to use the Kelvin scale for showing temperatures, and temperature rise. As you say, the OP should have said 90⁰K over ambient, which would have been correct. Celsius/centigrade scales are used by others, for example the weather bureau. Doctors use Fahrenheit when measuring body temperature. Contrary to western opinion, Indians also have a normal body temperature of 98.6⁰F- neither hotblooded nor cold So, we use all the scales. But we don't mix them up, like say, miles per litre or kG per square inch or something like that.

Refer www.copper.org or www.copper development association for busbar chamber design/construction

I am impressed by anyone who can make any sense of this posting and offer a sensible answer. 'Up the garden path' is applicable here. I can possible see an issue at the post insulators with creepage, but to be sure and offer a sensible answer to help. Well, perhaps re-posting the question properly written, is most advantageous to all.

Couple of small points:-

K (Kelvin) does not have degrees. It just is. (Small k = 1000).

K with respect to switchgear is usually referring to temperature rise, above ambient, which makes sense of the original post.

It is very common for busduct (bustrunking) to run at very high temperatures, a fact not always made clear by the manufacturers. The problem then comes when it is connected to a system which cannot necessarily handle such high values of K and a buffer zone is required with oversize conductors, ventilation etc.

In this case there may be another problem altogether e.g. bad design, bad manufacture, bad installation.

Thank you very much. i did not know that the degree has been dropped ! How stupid in this day and age, with so much on Wiki etc.

Coming to OP's problem, i have only seen eddy currents cause this. There should be no currents at all in the steel enclosure anyway, unless steel happens to be between phases.

My fault. I knew better, too. Kelvin is an absolute value. No superscript needed.