SMA Combi-Switch questions about UL rating [RE-wrenches]

[Steve Johnson]

Alan,

Yes we use it in the same way you described.

Larry, the way I understand it Sq D makes this switch for SMA (both 
German companies).  Why would they agree to do this if it can't be used 
for anything?  I mean if you can't put 4 strings on it what is it?

It happens we have used it only with the Sharp 170 so far.  Isc is 5.5 
so 2 strings on 1 pole is 11 amps.  Its rated for 11.5 amps short 
circuit.  Maximum current is 18 amps per pole.  I think this is the 
intended use and also that Sq D and SMA make good products and have good 
engineering.  But I may be all wet. You know - like the time I thought I 
was wrong but it turned out I was right after all?


Allan Sindelar wrote:
> 
> 
> ----- Original Message ----- 
> From: "Larry Crutcher, Starlight Solar" <larry at starlightsolar.com>
> To: <RE-wrenches at topica.com>
> Sent: Wednesday, December 12, 2007 6:33 PM
> Subject: RE: SMA Combi-Switch questions about UL rating [RE-wrenches]
> 
> 
> >
> > Yes Steve, but the fact that UL HAS limited this switch to 11.5 amps for
> > PV use must be considered. Just because SMA packages it does not
> > invalidate the original UL restriction. I can't say it "sounded
> > reasonable" to an inspector or insurance company or attorney or judge.
> > You get the picture? There is a reason for the limitation.
> >
> > Are any wrenches using the HU361 for more than 11.5 amps of PV?
> 
> Yes, Steve, we are. Here is our logic:
> According to the SMA spec sheet
> 
> (http://download.sma.de/smaprosa/dateien/4286/Combi-Switch_Flyer_081106.pdf)
> 
> ,
> the Combi-Switch is designed to match well with the SB6000 using four
> strings. It is rated for up to 40A, with 4 10A Touch-safe fuseholders. 
> So we
> have used it with four strings of ten 160-170W 24V modules.
> 
> I think the key is that SMA has had their product, the Combi-Switch, 
> listed
> by ETL (not UL) to UL1741. Bingo, end of story, install according to the
> manufacturer's instructions. The fact that it's based on an HU361 is
> irrelevant; it's now a separate listed product.
> 
> At least, that's how we have seen it. Could be wrong, though...
> 
> Allan @+E
> 



Steve Johnson
LightWave Solar Electric
Nashville, Tennessee


- - - -
Hosted by Home Power magazine

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

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

List rules & how to change your email address: www.mrsharkey.com/wrenches/etiquette.php

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

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

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
--^----------------------------------------------------------------