Din rail breakers

[tecnodave]

Schneider electric has several divisions that market din rail breakers.

The more popular Square D QOU line and the Schneider Multi-9 line.

The Multi-9 series that is applicable to solar is the C-60 Line DC telecommunications breakers. They are available in 1 and 2 pole versions with UL489A listings of 60 vdc  and 125 vdc and .5,1,1.2,1.5,2,3,4,5,6,7,8,10,13,15,16,20,25,30,32,35,40,45,50,60,63 amp ratings and with  b, c, and d curves. They are thermal/ magnetic.

The QOU line used to be rated at 60 vdc but is now rated at 48 vdc but the 60 vdc rating is still found in their applications data.

The Multi-9 line  are IEC rated as well as UL489A listed. They are more common in industrial applications than the QOU line and will be available at all industrial distributors. They will not be found at residential/commercial stocking dealers as they are not used in that field.

The QOU line is specified more in extreme environments such as waste water treatment, salt air etc, as Schneider considers that line to be more extreme duty than the Multi-9 line

I suspect ,IMHO, that the Multi-9 line will eventually replace the QOU line

Details can be found at     Schneider electric website.  Catalog number.    0860CT0201R06/10

Hope that info is useful,  David

[Halfcrazy]

Hm 125vdc will be a problem. With all the charge controllers being 150 or higher in voltage?

Ryan

[phonetic]

AC DIN MCB are rated at 230v AC nominal and 60v DC, used by the 1000s in Telecoms 48v DC applications.
I get my hands on 100 & 125 amps DIN MCB from decommissioned equipment

[tecnodave]

Ryan,

I realize that 125 volt is not sufficient for a lot of p.v. installations but I posted in response to the posting on wire clamping issue where a user was complaining about the clamping of the MNPV breakers and mentioned going back to QOU breakers. The QOU and also the QO and QOB breakers ore only rated 48 volt D.C. max. I use Multi-9 , QOU , MNDC and Carling breakers on my battery side and fast fuses or MNPV din rail breakers on my p.v. side as my string voltage is too close to the maximum voltage for the Multi-9 breakers.

David

[Vic]

Hi tecnodave,

Al of my comments on issues with AC DIN-Rail breakers (and believe those of others recently,  here),  were ONLY regarding the MNAC (Alternating Current speced) breakers.

These have a unique mechanical construction that uses a small screw with an unusual "Plus" head,  which is difficult to find the correct driver for --  it was mentioned that they were R&P.  The real Reed and Prince screws that I have seen (from the 1950s)  had a bit smaller width crossed slot than Phillips-head screws.

I have had NO issues whatsoever with the MNPV DIN-Rail breakers.   None.

The QO, QOU line at this time does have a spec for DC use for breakers rated from 10 A to or through 70 A.  Believe that the AIC rating is 5 kA  (all from memory),  which some believe is a bit low for some applications (such as those where one side of these breakers connect to a battery).

I DID state that the QOU breakers are preferred for DIN-Rail AC service,  because the very large slotted wire-affixing screws are VISIBLE and up front,  where it is quite easy to know that one has done a good job attaching the wires.

My comments about my experiences with the MNAC breakers were a bit too aggressive,  but know that MN is a very large customer of the manufacturer -- CBI -- and MN has an opportunity to communicate with CBI much better than do individual customers.

Ryan did say that CBI has improved the MNAC breakers,  but I have not seen any of these yet.

Not trying to ding you too much,  just trying to be clear on the breakers that were the subject of the recent Thread.   But your post on the other Schneider breakers was interesting.   Thanks,   Vic

[tecnodave]

Ok Vic,
I stand corrected , I was going from memory as what was said on the original posts, I guess I assumed the DC rated MNPV breakers. I have never seen the AC units as I am a stocking installer of Square D products used for homes and  commercial uses as well as industrial uses. Many of the industrial controllers that I service use the Multi-9 breakers and they are very high quality units. To the best of my knowledge of Breakers there are no other breakers comparable to the MNPV line from CBI at anywhere near the price.

From my experience with Square D the Homeline and QO line have a minimum AIC of 10k AIC with 22k , 42k and 65k AIC optional , The NEC requirements are 10 k AIC minimum for homes and 22k AIC for business and commercial.  I have not checked the DC k AIC of these breakers.

Model numbers vary as such:
QO 120.         I pole. 20 amp. 10 k AIC
QO-VH120.     I pole  20 amp. 22 k AIC
QOH-120.       1 pole. 20 amp. 42 k AIC
QH 120.          1 pole. 20 amp. 65k AIC

Same with the variants QOB,  QOU,  and QOCH

Code will vary depending on application, i.e. 100 hp 480 volt 3 phase water pump within 65' of 50 kva transformer 65 k AIC minimum breaker requirement.  Home with 125 amp panel within 100 feet of 25kva transformer. 10 k AIC requirement.   

I do residential and commercial electrical work for a living and use only the best components available for the job. I stock only Square D and Cutler-Hammer. 100% of my work is grid connected, I do not do solar as that would spoil my hobby.

David

[Vic]

Hi t d,

Thanks for the added info.
  Went back to find the Spec from Schneider,  dated 2008;

QO  10â€"70 A 10 kA 10 kA â€" 5 kA
Note 2 - DC ratings do not apply to circuit breakers rated 10 A

http://ecatalog.squared.com/pubs/Cir...CT9801R108.pdf

The last column is the 48 V one,  and it seems to say that for up to 48 VDC,  the max AIC is 5 kA.

This is a bit of an old spec,  and perhaps the details have changed,  FWIW.  OH,  and I was wrong about the range of QO type breakers that ARE DC rated,  it excludes the 10 A model  Memory is too dim.

Not to nit-pick.   I would use the MNEDC and MNPV breakers for DC applications to 100 A max.

Just my personal preference.   And also like the Carling & Airpax E-Frame CF breakers,  for some reason.

EDIT:  BTW,  here is the latest discussion of the MNAC DIN breaker Thread (that I recall):
http://midniteforum.com/index.php?topic=1465.0

Thanks,  Vic

[tecnodave]

Vic,

I agree with you on choice of breakers, all my new purchases are MNDC and MNPV. It is hard to beat NAWS price on these. I have a lot of Carling C and A breakers that I bought surplus so I will use them for applications that they are suitable for. The ones that I have are 48 volt rated, I know that the MNDC breakers are from Carling but I don't find them in my catalog, anyway Carling breakers are tough to get. I have a local Square D distributor who gets me anything Schneider so I have a quick supply there. I use all QO plug in breakers on my AC side using standard Square D panels as I stock a limited range of them. I mostly use Homeline for residential but they are not supported by Square D for commercial use, in any case the local inspectors do not approve them for commercial/industrial use. I use QO and Cutler-Hammer CH line for those applications.
Thanks for the update on the DC ratings on QO line, my catalogs only refer to the AC ratings as I use the residential products catalogs mostly. I'm sure that complete ratings can be found in the Digest but that is rather cumbersome to refer to for small jobs.

David

[tecnodave]

Vic,

You got me curious so I looked again at Square D and the 42 k AIC and 65k AIC rating is not available in the QOU, only in the QO and QOB plug on and bolt on variety. Both the 10k and 22k AIC @ AC are rated  5 k AIC at DC so I am again corrected. As I said I only do grid connected electrical work (not solar) professionally and use very little DC as such. I am still relatively new to solar although I have been off grid for several years now. I just got my Classic 150 last week so I can put my Chinese controllers to some less critical use. There is so much to learn, my choosing the Classic came as a result of visiting this forum and NAWS, there are a bunch of technically proficient users here and at NAWS.  Most of the local "professionals" know about grid tie only and have no clue about stand alone.

David