Is it just me, or have Wylex made a blunderous error?!

[Fin170]

The part I'm not sure about...is who bought that wylex board over the superior Schneider ones?

 

[D Skelton]

The part I'm not sure about...is who bought that wylex board over the superior Schneider ones?

I ripped it out and replaced it with a Hager.

Client spec.

 

[D Skelton]

Principle are similar and maybe my wording could have been better, I was discussing damaging eddie currents relating to the theme of this thread, you would require 2 opposing magnetic flux around the conductor to create a eddie current now as I see this this cannot be achieved due to limiting factors mentioned above which are -

Distance
Lack of sheath to boost the effect
No grounding of said sheath
Small nature of the currents discussed with these boards, usually <200amps

Yes you can create the effect to damaging results even in thes boards but you would have a lot of the above points involved.

Damaging or not, you'd still get Eddy currents though would you not?

What if it's a SP conversion board? That's a lot of potential neutral current! Not 200A worth, but enough for it to get warm surely?

 

[Darkwood]

Damaging or not, you'd still get Eddy currents though would you not?

What if it's a SP conversion board? That's a lot of potential neutral current! Not 200A worth, but enough for it to get warm surely?

I think we are all getting a bit over sensitive to the subject, no disrespect at first it got me thinking and think its one of those rare decent threads we get that the forum used to be about. The only time where I've witnessed <200 amp been a issue was 2 conduits feeding a multi-gang metal clad switch where the phases were split between the conduits and at only 40amps load the circulating local eddie currents made the conduit too hot to touch - with regards to your query here even a single phase at 200amps should not generate enough heat to cause problems because the circumstances are not right - we have no sheath currents so the currents have to be very large for it to even be a concern.

Yes!.. you're correct they still will exist but will not rise the temp' as the plate would disperse any small heat generated faster than it could ever build up or as known as the runaway effect.

PS - I edited distance out of my posts but will still exist in any the quoted format - this is becasue on read-up it gets complicated and generally for our discussion it is irrelevant.

 

[davesparks]

Damaging or not, you'd still get Eddy currents though would you not?

What if it's a SP conversion board? That's a lot of potential neutral current! Not 200A worth, but enough for it to get warm surely?

Yes eddy currents will occur, but will be minimal. By the same token the field around the busbars will have induce something in the steel plate, but it will again be so small as to be immeasurable.

If converted to SP and if all of the load is connected to the right hand side of the board you'll have ~125A max flowing through that bar. Something in the back of my mind is saying that in an experiment the temperature rise of a steel enclosure when tails are passed through seperate holes and 100A flows is around 1/2 degrees C.

It would be good, if you have the time, to actually put a decent current through that bar and see what happens.