24 volt dc

[guest119]

Seen an ammended control panel today sporting a bs 60898 DP type C 2 amp mcb controlling 24v dc.

Usually weidmuller etc din rail fuseblocks and links.

Something I am missing?

Boydy

 

[Knobhead]

And the problem is?

 

[dan86]

Something I am missing?

I think there's something We're missing here!

 

[ian.settle1]

Hang about Tel will be along soon with his crystal ball again.

 

[dan86]

he'll have had too many broons by now!

 

[chrish_1977]

I've consulted the magic 8 ball and it says more info please

 

[dan86]

mine says cannot predict now

 

[Knobhead]

No, still can't see it.

 

[guest119]

Aye, youre a cruel lot.
Searched this one and found the dc voltage rating shown by manufacturers to be 60v upwards.
Multi 9 System UL 489 Miniature Circuit Breakers - Schneider Electric Schneider Electric


Boydy

 

[Knobhead]

What size is the supply transformer feeding the rectifier?

 

[Engineer54]

Seen an ammended control panel today sporting a bs 60898 DP type C 2 amp mcb controlling 24v dc.

Usually weidmuller etc din rail fuseblocks and links.

Something I am missing?

Boydy

I can't see what your problem is or what your missing?? lol!! MCB's protecting DC circuits is perfectly acceptable, when they are designated suitable for DC protection by the manufacturer!!
BTW, the Schneider web page you linked too, is from they're USA site...

 

[Guest111]

I can't see what your problem is or what your missing?? lol!! MCB's protecting DC circuits is perfectly acceptable, when they are designated suitable for DC protection by the manufacturer!!
BTW, the Schneider web page you linked too, is from they're USA site...

An understanding of the functioning of mcb's perhaps?

 

[Darkwood]

C60HB, C60HC and C60HD are suitable for 24v DC .....

The number of poles required on your DC breaker is determined by the type of DC system you have:-

1- one polarity of dc supply is earthed
2- center point of the dc supply is earthed
3- insulated systems

As already mentioned you linked to a mcb designed to comply to UL requirements as areas including USA have differing regulations from us and the mcb's we use would not comply in their control systems..hence you have a differing dc rating and you have got yourself confused.

 

[SheffSimon]

I generally spec slow blow fuses for protecting 24Vdc circuits, for cost and panel space reasons.

 

[Clive P]

Hi,

Schneider MCB's are acceptable for DC provided you follow their guidance, they generally have to be down rated though. In their catalogue they have a page on 'DC operation of Miniature Circuit Breakers'.

Regards.

 

[Knobhead]

Apart from Phil can none of you realise the significance of my asking what size of the transformer feeding the rectifier was? Hint PFC!

Because DC doesn’t go through a neutral transition 100 times per second it is harder to break. To sustain an arc requires energy. You are not going to get that energy in a control panel due to the impedance of the control transformer feeding the rectifier! The energy let through is going to be minuscule!

 

[guest119]

What size is the supply transformer feeding the rectifier?

Ill find out next site visit Tony, the section I was in (ICA) only had the 110v controls tranny.

Boydy