DC lightning protection (was DC-GFP/2 protection) [RE-wrenches]

[jberdner at sma-america.com]

Alan:

I suggest orienting the modules so the J-boxes are as close as possible.

This minimizes the size of the inductive loop.
For maximum protection I suggest running the negative all the way out to
the last (lowest voltage) module in the same conduit. 
Obviously this will not work with MC connectors.

If you have any questions, or if I can be of any further assistance,
please do not hesitate to contact me.

Best Regards,

John Berdner

SMA America, Inc.
20830 Red Dog Road
Grass Valley, CA  95945
530.273.4595 (voice)
530.274.7271 (fax) 


-----Original Message-----
From: Rob Wills [mailto:RWills at AdvancedEnergy.com] 
Sent: Monday, September 02, 2002 3:38 PM
To: RE-wrenches at topica.com
Subject: RE: DC lightning protection (was DC-GFP/2 protection)
[RE-wrenches]

Hi Alan - say you have a 240V nom PV string voltage - 20 modules in
series.
Your rack is two modules high and 10 long.  The easy way to wire it is
along
the top and back along the bottom - making a wonderful loop to
inductively
couple to lightning.  Better is to cross connect so that you series
bottom
#10, top #9, bottom #8, top #7... That minimizes the loop area by
putting
twists in the string.  It's probably OK to cross over every 2 or 3 to
simplify - just minimize the loop area.

Regards

Rob Wils

-----Original Message-----
From: Allan Sindelar [mailto:allan at positiveenergysolar.com]
Sent: Monday, August 26, 2002 1:22 PM
To: RE-wrenches at topica.com
Subject: Re: DC lightning protection (was DC-GFP/2 protection)
[RE-wrenches]


Rob,
Please elaborate on what you mean by these two directives:
>In large systems, always minimize your source circuit loop area by
panel
layout and crossing over the
string wiring between runs of modules.
Thanks.
Allan at Positive Energy


----- Original Message -----
From: "Rob Wills" <RWills at AdvancedEnergy.com>


> Something else to understand is that it does not take a direct strike
to
> take out an inverter.  The PV system is sandwiched between the plates
of a
> large capacitor (ground and the lightning bolt) and/or can pick up
current
> by magnetic induction in PV source circuits.  In large systems, always
> minimize your source circuit loop area by panel layout and crossing
over
the
> string wiring between runs of modules.
>
>

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

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

List rules & etiquette: http://www.mrsharkey.com/wrenches/etiquete.htm

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

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com

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

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

List rules & etiquette: http://www.mrsharkey.com/wrenches/etiquete.htm

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

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com

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

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

List rules & etiquette: http://www.mrsharkey.com/wrenches/etiquete.htm

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

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
Or send an email to: RE-wrenches-unsubscribe at topica.com

T O P I C A -- Register now to manage your mail!
http://www.topica.com/partner/tag02/register
==^================================================================