Are there any 600 V rated PV Input Breakers available for use in a Mini-PDP with Schneider 100-600?

Graham Parkinson

It looks like Schneider's part lists have not yet identified a 600 V rated PV input breaker that fits in the PDP's.  Does anyone know what works in this situation?

It appears that PDP's have slots for QUO sized breakers. 

Schneider did give our installer a part number for a two pole four slot ( 75 mm wide) DIN rail mount breaker that is rated for 600 V but it looks like it won't fit in a Mini-PDP - perhaps there is room in a full sized PDP with some modifications to the slots?   Or would we have to fit this breaker in an external box or perhaps on a DIN rail inside the PDP?  Below is a photo of it off of the Schneider website:



And below is a link to this breaker as Schneider suggested to use for the 100-600 PV input:

https://www.se.com/ww/en/product/A9N61651/miniature-circuit-breaker-mcb-acti9-c60pvdc-2p-16a-b-curve-1-5ka-iec-en-609472/

The Schneider tech implied that when Schneider gets around to updating the equipment list for the 100-600 controllers, there will likely be a compatible Schneider breaker found that fits.   The photo that shows jumper wires included with the above breaker at the link makes it look like 2 two pole 300 V breakers jumpered in series to make a two pole 600 V breaker.  Suppose that's ok given they are ganged to operate at the same time, effectively lengthening the gap to aid in breaking the arc while switching.

Schneider's literature suggests that overcurrent protection isn't needed in a single HV string situation (the 100-600 Charge Controller is actually single channel, despite having two terminals, they are both common).   However having no overcurrent protection with 7 kW of PV at almost 600V in two strings coming together at the CC seems unsafe so I'd prefer including a 600 V rated disconnect rated breaker!

Schneider also suggested using their rapid shut-down remote MPPT Disconnect RS with the 100-600 CC but that adds significant complexity to an off grid remote location installation which only really needs a disconnect rated breaker.

BB.

Midnite does have 4x ganged breakers that can be wired for 1x pole @ 600 VDC break voltage.

https://www.midnitesolar.com/productPhoto.php?product_ID=336&productCat_ID=16&sortOrder=21&act=p

And our host has some 600 volt switched disconnects:

https://www.solar-electric.com/search/?q=disconnect+600+volt

There are several Square-D disconnects... Rated for 600 VAC/VDC with 3x poles (each pole is rated for 600 VDC as far as I could tell with a quick look at the specs.).

If you are looking for disconnects (typically 1-2 strings)--Then you only need "switching", not per string breakers.

When you get to 3 or more parallel strings (check solar panel ratings for series protection fuse/breaker rating)--Then actual breakers (i.e., rated 15 or 20 amps per string typically) are needed in combiner box(es)).

Just watch specifications, there are 600 VAC rated, and 600 VAC/VDC rated... DC current is much more difficult to "break" vs AC...

I am not trained or experienced with these devices--You should contact our host (NAZ/Solar-Ellectric.com) and talk with engineering if you need more details for proper configuration.

-Bill

Dave Angelini

Tech support at many companies is entry level and the tech often read from scripts or similar computer based support systems.

Tech support is not Engineering but a group that reports to Engineering. I think they told you incorrectly or someone spoke incorrectly.

If you read the specs on the PDP you would know it is not UL listed for 600 VDC.

 Even if the PDP was listed for higher than 150VDC you would be a bit crazy to run high voltage with battery voltage. It is bad practice for  high reliability Offgrid Power Systems. Keep the high voltage in a separate box and combine up to 2 unfused strings in the mppt-100-600 or in the Disco box.

 It is safe to not fuse 2 strings but do it if it makes sense to you. The strings can be joined and then switched with a single 600vdc pole 30A rated.

600vdc is not for the untrained. You need to know all about it by doing your due diligence. Good Luck

Graham Parkinson

Thanks BB and Dave for the excellent advice.  Still early days in our planning but these are all important considerations.   

We came to the same conclusion that an external 600VDC rated two pole disconnect switch is the way to go for the 100-600 controller, but had missed the fact that the PDP itself is only rated for 150 VDC wiring.   

So the way to go is to route external EMT conduit from the panels thru the disconnect and then into the CC, bypassing the PDP with the high PV voltage.

Although there are some good points about going the 100Amp-600V controller route, I like the redundancy and greater string isolation from using 150 V controllers (i.e. reduced effects of partial shading from multiple parallel strings).

Also, for some roof spaces like ours, it can be hard to combinatorically match a high target string voltage of around 500 Vmp compared to the increased number of options that result from more shorter strings with 150 V controllers.  Hopefully Schneider updates the design of their 150 V controllers soon as they do seem to have their uses. 

Running 600 V in a salty, damp seaside setting would mean that everything electrical has to be done super well.

Dave Angelini

For me, and doing this 100's of times, 600vdc is about the only way. Many more options and the mppt-600's are shade tolerant and do a great job in low light. You are right about panels being shadowed but in my mind that can't ever happen.

 You have to remove trees and obstructions for Offgrid solar.

You are dreaming about the 150v controllers being updated. They are a mature and bulletproof controller back to 2005 era.

 Still if you think that you should feed it back to Schneider. They are doing a much better job in the last 3 years of listening and supporting.