In the past 25 years I have watched the power systems get super sized.
Where a nice easy 500 kVA transformer used to be plenty they decided to move to 750 1000 and I even see a few 1333 ( where that number come from ? )
Where a 500 was too small we used to build electrical vaults with an A side and B side and use two 500…
So where am I gong with this???
The bigger the transformers, the larger the larger the cables the more available energy to to cause really destructive faults.
At the same time I notice breakers that used to be just fine at clearing a short circuit and preventing accidents and fires these are now failing and causing the accidents and fires.
New standards are introduced with stronger breakers, better fusing and more robust enclosers.
But I think we tottaly missed the point.
We should have kept things small to reduce the available fault currents in the first place.
Did you know that a lot of the IEC stuff made in the EU countries can’t deal with the faults our stuff here is designed for?
They have better standards and actively design to keep these currents down.
We just super size …
So when you buy something made in another country you had better question before hand, can this deal with a North American power system wide tolerances and very big transformers and cables designed to be cheap and efficient ( but generate Hellish fault currents )
I get asked to do things sometimes ( soapbox time )
They say "Wally old man " go and put this lexan window in that S&C switch… replace the broken safety glass…
Safety glass? Lexan?
Are you sure plastic will not liquefy and blow out under a major fault.
What if that switch fails you do not need PPE to switch because its metal clad but is it still going to do its job if I use Plexiglas glass?
Now I am the stupid trouble maker for refusing to do this without explicit proof from S&C this is OK to do?
How many other people just randomly do that?
How many people are just doing what they are told around here and random substituting parts from the cheapest supplier ( our global procurement program to save money )
I have one foot stuck in the past, I do not like to wear the heavy suit so I don’t but I get mad about using parts that would require me to where a flash suit because the super sized power system and dubious parts. ( I never need this before… )
And I have that other foot firmly planted in the the reality of today where you can’t trust things to work right anymore and you need to be afraid they will blow up and set you on fire.
So keep this ramble in the back of your mind.
The NFPA in the USA set the standards for electrical equipment not to set you or your stuff on fire.
But today’s stuff is even better at setting things on fire than ever and tha only thing between an accident and normal function of safety and protective devices is the promise from UL and CSA that they tested that electrical apparatus under the worst conceivable conditions of use today and it passed and meets the current standards.
Don’t buy cheap Ebay stuff.