All the years I chose a contactor based on the current rating on the box. But then I begin to put the product database together (see electrosource.org) and the differences is vast.
So who is right and who is wrong…is the Americans or is the Europeans right (Both can’t be right?
I choose a contactor and on the box it says Ith=25A IEC and when I check the UL=21A or the other says 45A(IEC) and 40A(UL).
I am going to pull 43 A so which one should I believe?
Should I pull a patriotic card that says I am American so I will go with UL?
Or when British we thus go IEC? (Ahhh, I said BS on purpose for I realize there is another potential British standard, different from the “European” IEC which might just have a 43Amp rating?
Then the obvious came through quickly – the actual standard tests are different and these values are arrived at under different conditions.
The only solace I could find besides other deeper technicalities of the test is that Ith is done at 400V and the UL equivalent(genl) at 600V the UL “arrived at ” current value being slightly smaller gives me some peace of mind that they will be exactly the same at the same voltage.
So maybe we as electricians must begin to interrogate these different conditions and choose what is technically the correct one, not just for oneself /us, but for everybody.
Or are we as a species not there yet?
What do you think?
Just for your information …it gets worse…Within one standard one can have complete different values just because of an older or sub-division within the same standard or because of a different stipulation within a different country example:
See how a IEC rated MCB can have a kA rating varying between 6 and 10kA –
Standards determine kA at 6 or 10kA depending on how interpreted.
Does anyone know exactly what the future holds for this double standards?
Yes, I realize the one is more stringent because of being domestic and the British is overly conservative…or not?
But I thought these standards does not represent sentiment but rather conclusions based on scientific fact.
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