Author Topic: Split negative bus bar in MNPV6-DISCO?  (Read 356 times)

Vic

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Re: Split negative bus bar in MNPV6-DISCO?
« Reply #15 on: July 03, 2018, 01:53:34 PM »
Hi John,

Some of those E-Frame breakers from Carling,   Airpax,   etc  are definitely  not rated to carry the (handle) Rating continuously.   Some may well be.   But good catch John,   and good that you are checking.

All of the MidNite DC breakers are  Magneitc-Hydraulic,   and ALL   are rated for continuous current at the Handle Rating,   at least,   to 40  or 45 degrees C.

Larry,   the  Panel Mount DC breakers from MidNite (MNEDC)  up to 100 A Ratings  are a smaller Frame size  than those used by Schneider.

IIRC,   MidNite commissioned an adapter from the cutout for the E-Frame breakers to the smaller Carling units (D-Frame ?,   IIRC).   But  this adapter seems not to be commonly-stocked at the Distributors that we use.

I like the larger E-frame units,   but they take more space,   and are  more expensive than the MNEDCs,   to 100A rating.

FWIW,   Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

ligwyd

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Re: Split negative bus bar in MNPV6-DISCO?
« Reply #16 on: July 04, 2018, 02:54:32 AM »
These ones?

http://www.midnitesolar.com/productPhoto.php?product_ID=197&productCatName=Breakers&productCat_ID=16&sortOrder=13&act=p

The Carling and Airpax breakers I have now have do not need lugs attached to the cables to attach to the breakers. I like just putting the wire in and tightening it in. I'm sure both style are just fine.

Re: the breakers I have now I was able to find the following:

http://www.magnum-dimensions.com/sites/default/files/MagDocs/64-0041-Rev-C-DC-Load-Breakers-BM_web.pdf

They are in fact 75 and 100 amp breakers labeled by or for Schneider at 60 and 80 amps. This was due to the fact that Schneider needed these breakers to have a continuous rating of 60 and 80 so these are the breakers they used. Not really sure why? Had the young engineers with Schneider wondering as well. 

Also in my Schneider manual as previously discussed, they call for the breaker between battery and charge controller to be the max rated output of the controller x 1.25% as per NEC.
Not sure why NEC would want that. I'll have the look into the codes here in Canada. The biggest cable that the MPPT 60 150's can accept without a splicer block is 6awg and its already pretty tight in there as it is. Now if an inspector sees the 80 amp label on the breaker He might want 4 awg wire in there? I would think a 60 amp with continuous rating would be the way to go?
Have a good night..
John

FNG

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Re: Split negative bus bar in MNPV6-DISCO?
« Reply #17 on: July 05, 2018, 06:19:05 AM »
Some controllers regulate really well and some don't when it comes to output amps. For example, if you put more PV on a classic than it can process it will limit right at the amperage set in the limits menu with no overshoot. The Schneider will, however, overshoot that 60 amp limit thus Schneider wants the 80 amp breaker on the battery side to prevent nuisance trips on edge of cloud events

ligwyd

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Re: Split negative bus bar in MNPV6-DISCO?
« Reply #18 on: July 06, 2018, 01:00:10 AM »
Makes sense. Might be pulling out the 6 awg wire or installing a 60 amp continuous rated breaker. I'll leave it in for now and come back to it if I have to. Since I am only putting 2340 watts to each controller and the fact that they can handle an over-sized array of 6720 watts max each I think I am ok with it the way it is for now:)
Thanks again :)
John