Confirmation of 100% duty cycle, OB breakers [RE-wrenches]

[Allan Sindelar]

Wrenches,
Robin Gudgel of Midnite Solar left me a phone message responding to the same
question, that I had posted to the list prior to Phil's question.  The gist
of Robin's message is as follows:

What UL does is test breakers at the rated maximum load in sets as used in
the components in which they're mounted. [In the case of the PSPV, this is
as Chris describes below.] With the CBI QY series, the biggest is 63A, and
they have been tested as either dual or triple units together, with 63A
going through all the breakers at the same time. As the breakers are
magnetic/hydraulic, external heat doesn't affect their trip curves. Bottom
line: they're rated for 100% duty cycle. Arbitrarily derating them to 80% is
hogwash. So it's not a real issue.

Allan at Positive Energy

----- Original Message ----- 
From: "Christopher Freitas --- OutBack Power" <cfreitas at outbackpower.com>
Sent: Tuesday, November 07, 2006 11:58 AM
>
> All of the breakers used on in the OutBack products are 100% rated
> hydraulic-magnetic type breakers EXCEPT where we have used the square-D
> breakers in the AC bypass assemblies (which are being replaced with the
> new FLEXware systems which use only the OutBack/CBI type breakers.
>
> We did run the 100% approval tests on the PSPV with the box completely
> loaded with 15 amp breakers carrying a total of 180 amps DC through it
> (a total of 12 breakers @ 15 amps each).  So it is not an issue there.
>
> We also did testing on the DC versions "PS" enclosures for 100% testing
> but it was not as thorough as what we did on the PSPV.  Since the AC
> versions of the "PS" enclosures did not have all 100% rated breakers in
> them we did not test these versions at all.
>
> So - the bottom line is that the PSPV is acceptable for 100% duty use -
> the PS2/PS4 DC enclosures and somewhat.  We are starting to ship the new
> FLEXware enclosures versions and we are completing the 100% testing on
> them - both the AC and DC versions.
>
> Althought the hydraulic/magnetic breaker's trip level are not affected
> by the breaker's temperatures - the breakers will get warm which could
> cause the terminals of the DC breakers reaching the temperature rating
> of the cable and terminals involved. We do not pack in as many breakers
> together in the DC enclosures so I have not seen temperature rise to be
> a big deal in my experience.  The AC boxes might be where temperature
> issues occur - but most systems can live with a 80% dearte if required.
>

> pundercuffler wrote:
> >
> > Christopher,
> >
> > Can you help clarify an issue that arose during a John Wiles training
> > yesterday?
> >
> > Are the OBDC, OBAC and OBPV breakers rated for 100% duty cycle as
> > mounted in their enclosures?


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