AWG vs. mm2 Cables procurement 1

[Okpower]

Hi all:

I am involved in the procurement of about 20.000 meters of cables to be installed in a new Oil refining Plant.

The contractor that is doing the design of electric system advised us to specify the size of cables in mm2, because there are more cable suppliers that handle this unit.
At the end, overall price of cables will be much lower.

Please, give your suggestions/opinions. We are used to handle size of cables in AWG.

Thanks in advance.

 

[rbulsara]

Are you asking how to find equivalent mm2 size for a given AWG size? If so, there are a lot of comparison tables available such as

http://www.ilsco.com/AWGWireSizes.aspx.

There is no exact match, but you can find the closest size, verify ampacity and make a table that gives you the equivalent mm2 sizes for your purpose.

You may have to spend some engineering time and effort to find acceptable mfrs as well, if you do not want to be at mercy of the contractor.

Also depending on the location, preferred wiring method varies ( pipe and wire vs. armored cables, single core vs. multi-core, etc), so does the ampacity. So verify those specs and specify accordingly.

Rafiq Bulsara

http://www.srengineersct.com

 

[jghrist]

What national standards will apply? If NEC, then using metric sizes will require larger cables so that the size will be larger than or equal to the US size listed in the NEC. I suspect that if the cable types have to meet US standards, then there will be more manufacturers with standard offerings in AWG and kcmil.

If European standards apply, then definitely go with metric sizes.

 

[ScottyUK]

There are a lot of countries in the metric world who are making cable which are, for want of a better term, absolute crap.

Countries of origin which I generally prefer to avoid because of too many bad experiences include: China; Russia; Greece; Turkey; India. I'm not saying every manufacturer in those countries make bad cable, just that there are quite a few manufacturers in those countries who make cable which does not meet the standards which are moulded into the sheath. Be careful if you don't know the company involved - but equally if a big manufacturer like Prysmian has an operation in one of those nations then don't discount them.


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If we learn from our mistakes I'm getting a great education!

 

[rbulsara]

I agree that all mfrs are not created equal. Stick with a few reputed ones.

Rafiq Bulsara

http://www.srengineersct.com

 

[AusLee]

Okpower,

Don't forget also to check the insulation, the American cable is most likely to come in some form of THHN ... (so many insulations while in the sq. mm world there isn't much variety.

 

[davidbeach]

There's only one form of THHN. There are a variety of possible insulations, of which THHN is just one type.