Eddy currents

[SparkyJoe]

A 3 phase DB has been wired with 3 X 25mm lock nut and bush into steel trunking, The ballbag has taken earths in one, neutrals in another, and phase conductors in the 3rd.

As im missing this bit of technical information, Do you get eddy currents if you have 3 phases going in one hole, or just if you have one

Cheers

 

[topquark]

A 3 phase DB has been wired with 3 X 25mm lock nut and bush into steel trunking, The ballbag has taken earths in one, neutrals in another, and phase conductors in the 3rd.

As im missing this bit of technical information, Do you get eddy currents if you have 3 phases going in one hole, or just if you have one

Cheers

IF!, perfectly balanced no net current on the neutral (very unlikely though!), really need neutral, CPC and all phases in the one hole, to eliminate possibility.

 

[GLENNSPARK]

IF!, perfectly balanced no net current on the neutral (very unlikely though!), really need neutral, CPC and all phases in the one hole, to eliminate possibility.

yep..

i came across one not long back..

old 3 phase panel loaded up with 3036s

several entrys used for the phases & neutral....

it wasn`t anything to do with my work there....but it still went into the comments on existing installation box martin...

 

[GLENNSPARK]

i think Darkwood had one as well..just the other day...as he was posting about it in here....and that was the handywork of an NIC AC...

so their out there....these ballbags...as has been described already...

 

[topquark]

Good for you matey!

Only get eddy's with changing fields, so if all phases are perfectly balanced (for all time) then no change in field for the phase bunching ... could still get something on the neutral or earth though even then, so still dodgy practice!

 

[GLENNSPARK]

Good for you matey!

Only get eddy's with changing fields, so if all phases are perfectly balanced (for all time) then no change in field for the phase bunching ... could still get something on the neutral or earth though even then, so still dodgy practice!

but like you says...its unlikely...

there were multiple single phase loads on that thing i saw....various I N ...

its dicheads thats doing it...

i suppose they think it looks `neat & tidy`...or summat like that...

 

[uksparks]

I rectified mine by using a piece of paxolin and then they were ll going through the same hole then, yet slightly spaced, I had been meaning to do it for a while..

 

[GLENNSPARK]

I rectified mine by using a piece of paxolin and then they were ll going through the same hole then, yet slightly spaced, I had been meaning to do it for a while..

slots between the entrys does it as well...

 

[topquark]

but like you says...its unlikely...

there were multiple single phase loads on that thing i saw....various I N ...

its dicheads thats doing it...

i suppose they think it looks `neat & tidy`...or summat like that...

Yep only needs a phase to go and yer shafted, ain't always under your control when things go pear shaped. zzzz

 

[PEG]

slots between the entrys does it as well...

Which,ironically,is exactly how and where i met the missus...

 

[uksparks]

slots between the entrys does it as well...

I had drilled holes first before thinking about eddy currents, it was never actually made live with them in separate holes, like I say i did resolve the problem using paxolin. Yeah it's ok, not bad, could be neater but far from the worst out there, I don't have a great deal of experience with three phase Nd hooking a new board up, but we all have to start somewhere.

 

[davesparks]

slots between the entrys does it as well...

Cables in trunking with a paxolin gland plate between it and the DB works well too. Plenty of room to organise your cables nice and neat too.