Smart $:
If there is already a GFCI upstream, single pole breaker instead of two pole breaker for an ungrounded 460V two wire system may be used. It results not only in safer operation but also may lower cost (single pole instead two pole breaker).
What do you think from the point of view of CMP?
Such a thing exists, perhaps, up to AC 276 Volts:
Is that a breaker? If it is not then you haven't done much more than throw something against the wall to see if it sticks.
True or not true Haji?
Poll it, Action!
What is your problem?
I wouldn't necessarily make that claim, but it definitely is not something in high enough production levels that it would cost less then a two pole breaker that is more common to see in higher production levels - which is what the original application was about for this - at least in North American markets.
I can agree with that, and that Haji maybe should have called it GFP, my main intention was to mention that it likely would not cost less then using a typical 2 pole breaker, without even looking at exactly what he had or considering any other issues it may have for this application.
A little late to this topic branch, as you can see, but the two single pole vs one double pole relates back to the requirement for independent or common trip.Smart $:
If there is already a GFCI upstream, single pole breaker instead of two pole breaker for an ungrounded 460V two wire system may be used. It results not only in safer operation but also may lower cost (single pole instead two pole breaker).
What do you think from the point of view of CMP?
A little late to this topic branch, as you can see, but the two single pole vs one double pole relates back to the requirement for independent or common trip.
Where required to be common trip, there is no choice in the matter... and common trip definitely cost more than independent trip.
On the other hand, an independent-trip double pole costs just a bit more than two single pole breakers plus handle tie. Typically an independent-trip double pole is just two single pole breakers factory riveted together and factory-installed handle tie. Some may cost a bit more than 2x due to market demand vs. supply considerations made by the manufacturer and distribution chain.
Given other replies to your post, there's no need for me to add any comment on the GFCI portion...
The replies including yours did not deal with the viability of my suggested code proposal for ground fault detection and a breaker/alarm combination for an ungrounded system in context with the usage of single pole breaker.:roll:Given other replies to your post, there's no need for me to add any comment on the GFCI portion...
Good point. Must have been thinking too small when I posted.
If I were a CMP member considering your proposal, I would reject it on the basis of inadequate substantiation. This happens quite often to good proposals that simply lack substantiation, or substantiate with abstract and/or vague notions.
