need help with Battery disconnect outside

Spacecoast Solar

I plan to install a grid tied system using Outback inverters and charge controller.  Equipment to be installed in an exterior garage with a 48 volt battery bank of FLA batteries in a battery box on a slab on the outside of the garage.  This installation is located in Florida, so no possibility of freezing.  To comply with NEC 690.71(H) I must have 48 Volt battery switched at the equipment and the source as well as the source being fused.  I could have a 125 amp breaker(Midnite Solar MNEDC-125) that would satisfy the switch & fuse but there is no NEMA-3R enclosure available.  Blue Sea battery switches do not meet code for residential applications, they are for marine use.  What can I use 48V 125 amp NEMA-3R

zoneblue

You might look at midnites remote disconection systems, "Birdcage" etc. They are targeted at these new regulations.

Vic

Space..,

You might also try joining the MidNite Fourm,  and perhaps asking the question in this Topic area:

http://kb1uas.com/mnsforum/index.php?board=4.0

At this point,  the Birdhouse system may be limited to GT inverters,  IIRC.     Vic

Spacecoast Solar

Thanks, but I have looked at the Disco and Rapid Shutdown and they are for disconnecting the PV modules, not for battery source with 1/0 cable suppling 125Amps at 48 volts.  I even called Midnite Solar tech support and several solar equipment suppliers.  What do installers do for battery disconnect outside?  

Vic

Schneider/Square D,  has  had some DC-Rated Disconnects (just a switch)  in what looks like a 3R enclosure,  but,  IIRC  they may not have one rated for 125+ Amps ...   will try to look.

Saw your Posts on MN and the OB Forums,  and there are some Pro Installers left here,  so hope that you find something.
 Vic

zoneblue

Not so sure. The big 200A breakers come with a remote disconect terminal for use with birdhouse.

Vic

This Schneider box looks very inexpensive!

http://download.schneider-electric.com/files?p_Reference=3100HO1101R1111&p_EnDocType=Handout&p_File_Id=74290630&p_File_Name=SolarDisconnectSwitch3100HO1101R11_11.pdf

This Link may not really work ... GL,   Vic

Vic

Some of the MN breakers do have Shunt Trip terminals,   but am not sure where MN expects them to be mounted.

Believe that the enclosure for such a breaker would need to be Listed for the specific application.

Perhaps the AHJ for the local jurisdiction has some guidance on what they would want to see ...   it is a bit surprising that this part of the 2014 NEC is being enforced.

Good Luck,   Vic

zoneblue

Apart from the birdhouse stuff being pricy, to my mind the point of it is that its by definition a SHTF scenerio where its required, and yet with all the electronics involved, suggest it may not be exactly "fail safe".

I have given this some thought in our system, and when it comes time to next reorganise things here i plan to move the disconect a little futher away from the battery. Large (expensive) cables mumble mumble. Probably the best solution is to mount the disco on the other side of a fireproof wall. However the disco still needs to reasonably aceesible in the event of a house fire. Which really just all leads you to , where possible, a stand alone structure for the batterys, and gear.

Vic

Guess that the bottom line,  is,  that this is an unusual application,  as I believe that there is a wall separating two parts of the system,  thus requiring a Disconnect at the exterior.   This Disconnect needs to be outside of the battery enclosure,  but accessible.    There appears to be very,  very few solutions ...

Perhaps re-thinking the layout of the system would be in order,  if a 3R DC Disconnect cannot be found at a reasonable price.

Having batteries outside,  is often not the best of ideas,  as batteries do not really like heat,  and so on.

Good Luck,  Spacecoast,     Vic

Spacecoast Solar

Thanks, Vic & zoneblue for the info.  My problem in Florida is a State statute that requires certification of any solar PV system by the Florida Solar Energy Center before I can even pull a county permit.  $250 application fee and certification required, whether a hugh corporation installing thousands of systems, or a homeowner installing a 4KW on a detached garage.  Application & plans must be submitted on-line in PDF format.  I don't have a CAD s/w package, so we scanned drawings.  I submitted my plans and they gigged me with 3 pages of requirements and corrections to make, like numbers too small to read, and this disconnect code.  I am trying to do it right, but they really make it difficult. The Schneider Solar Disconnect Switch would do the trick but I checked and it is $2084.  I didn't realize that exterior battery placement was so out of the norm.  I was rethinking the layout, now I believe that is the most economical solution.  I just have to redesign the battery box and make space for it inside the garage.  Thanks again guys.

Dave Angelini

Are you really sure that the DC must disconnect outside or just be able to shut down the inverter charger outside?
The last inspectors I have dealt with just wanted a remote power down of the inverter/ charger.
A $10 part to a Radian or Schneider XW.

Vic

Dave Angelini said:

Are you really sure that the DC must disconnect outside or just be able to shut down the inverter charger outside?
The last inspectors I have dealt with just wanted a remote power down of the inverter/ charger.
A $10 part to a Radian or Schneider XW.

Looks like the local jurisdiction is enforcing new provisions of the 2014 NEC  ...

specifically,  from solarprofessional.com ...  

 "  ...   Disconnects and overcurrent protection. Section 690.71(H) is new in NEC 2014. It describes five requirements that apply to battery circuits that are more than 5 feet in length or that pass through a wall or partition. Per Subsection (1), a fused disconnecting means or circuit breaker must be installed at the end of the circuit closest to the batteries, since these are the source of potential fault currents. Per Subsection (2), where a fused disconnecting means is used, the connection from the battery must be made on the line side of the device, since these terminals will be energized even when the switch is in the off position. Per Subsection (3), OCPDs or disconnects are not allowed in battery enclosures “where explosive atmospheres can exist.” This applies to lead-acid batteries, for example, which off-gas hydrogen   ..."

Am not an NEC expert,  but am beginning to feel more pain.   FWIW,   Vic

Dave Angelini

That is ridiculous  (to the OP) as most can barely enforce code 5 years ago.  The OP should check what year code he has to meet. It is BS that they should have to do anymore than what their state requires at county level.

And anyone in Florida should really know quite a bit because of the level of expertise there.

The Midnite birdcage can shut down a battery bank (and the DC solar) with their remote trip breaker (AC or DC) but if I really had to do this I would build the system with the battery with-in 5 feet of the DC disco/breaker and avoid this work and get a better system with short wiring.
And really all you need to do is shut down the inverter/charger remotely  (RPO) and also have the Solar DC disconnect right there outside the building to shut down up at the array.

Vic

Hi Dave,  in an above post,  Spacecoast Solar did say,    ...   " I just have to redesign the battery box and make space for it inside the garage   ... "

So,  DO think that he is going to place the battery bank inside the garage,  as I read it,   FWIW,   Vic

Dave Angelini

I missed that also so yes he should put the battery in the garage where it belongs any way. The Radian calls the inverter shut-down an EPO and Schneider calls it RPO. In any case it is a good thing for anyone to have as you can shut down all the AC loads and send the inverter to sleep from outside the building. In a wildfire it is nice that the fire guy's can shut down a battery inverter and since most offgrid is not on the roof they do not have that problem either.

Brock

I like the idea of a "remote" shut off and currently don't have one.  I looked around Wind&Suns site and searched the web and can't find a "Schneider RPO", I am probably just blind...

Dave Angelini

Hey Brock! Been awhile!  Just look in your xw manual and run a switch outside. For code it needs to be labeled well or self-evident to a foreperson. 

Spacecoast Solar

Thanks for all the help & comments, guys.  I have received my certification from FSEC, and PE stamped drawings.  Plans have been submitted to my county building department, now waiting for permit to proceed.  I'll let you know how it goes.