Using Outback PSSB with Fronius Inverter. What else? [RE-wrenches]

[Jeff Clearwater]

<x-flowed>
 

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
We can reduce your unsecured credit card debt by 40-60%. 
Don’t file bankruptcy.  Be Debt Free in as little as 1 year. Take 
control of your situation.  100% FREE Consultation.
http://click.topica.com/caacZptbz8Qcsbz9JC9a/KnockOutDebt
-------------------------------------------------------------------

Hi Jeremy,

Technically you can use a PSSB breaker to both combine two strings 
and then act as the disconnect.  The poles are rated for two wires. 
You can also do the same with a Square D HU-361 or GE equivalent.

However although I have done it several times, I can' t say I'm 
overjoyed with using the PSSB as the combiner too.  Anytime use use a 
breaker lug to combine wires you run the risk of not getting one of 
the wires fully landed tight - if it were to pop off you'ld have a 
high voltage wire floating around in your disconnect.  Also Outback's 
negative block for those PSSBs are pretty small for stuffing two 10 
AWGs into or even 12 AWG even though they are supposedly rated for 10 
AWG.  I have had EO send me the slightly beafier DIN mounted negative 
block to make that negative connection.

I have in some of those systems done the combining with a split-bolt 
connector or power distribution block and then jumpered to the PSSB. 
The PSSB in itself makes a fine high voltage disconnect and I like 
them when I'm doing pole mounts instead of Square D or GE disconnects 
when aesthetics is an issue.  Nice white sealed boxes with no 
externally accessible switch for kids to play with.

I've also seen installers avoid the combining issue at the disconnect 
by running both strings all the way to a HU-361 and using separate 
poles for each of the strings and running the switched output to the 
inverters where there is usually a multi pole input.  This works 
nicely when the disconnect and inverter are mounted close to the 
panels - like on the roof or all on the pole.

So there are several ways to do it.  The HU361 or equivalent if the 
most inexpensive high quality versatile (3 poles) high voltage rated 
disconnect out there and I use them when I can.  But the PSSB is a 
really nice but significantly more expensive alternative.  Either way 
you have to figure how to combine.

Energy Outfitters makes a nice pass-through combiner box that allows 
two strings to come into one.  They mount right on the racks - but 
they are pricey for just a pass-through box.  They are nice for 
transition boxes from the MC connectors to your conduited wire down 
to the inverter.  Especially nice when you have low profile racks and 
don't want a big J-box there.

Many of us also just any sort of outdoor rated steel or PVC j-box at 
the array and combine there with a PDB or split-bolt or wire nut or 
bundy connector - cheap and effective.  I personally don't like PVC - 
especially in really sunny locations - as it tends to turn white and 
look ugly and I question if 20 years down the line they wont' crack. 
 From there now you have one wire and either a HU-361 or PSSB is a 
fine choice.

So have fun and welcome to the world of grid-tie details.

Jeff C.




>Outback Power and/or Wrenches,
>
>I am trying to come up with a safe way to wire in 2 strings of 
>14-12v modules to feed the dc side of a Fronius IG3000.  I have 
>looked over the manual for the PSSB and somewhat understand it!
>Bear with me, this is my first grid tied system.  Could I use the 
>PSSB 6-pole breaker, or do I need 2-PSPV breakers prior to it.
>
>Thanks in advance!
>Jeremy
>All Solar
>CO, USA


-- 
~~~~~~~~~~~~~
Jeff Clearwater
Village Power Design Associates
Sustainable Energy & Water Solutions for Home & Village
http://www.villagepower.com
gosolar at villagepower.com

530-470-9166
877-SOLARVillage
877-765-2784
425 Nimrod St.
Nevada City, CA 95959
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`~

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Claim your fully stuffed Christmas Stocking now
http://click.topica.com/caacVmdbz8Qcsbz9JC9f/PermissionData
-------------------------------------------------------------------

- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://lists.topica.com/lists/RE-wrenches/read

List rules & etiquette: www.mrsharkey.com/wrenches/etiquette.php

Check out participant bios: www.mrsharkey.com/wrenches/

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at homepower.com

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

For Topica's complete suite of email marketing solutions visit:
http://www.topica.com/?p=TEXFOOTER
--^----------------------------------------------------------------


</x-flowed>