Repairing module back [RE-wrenches]

[Bill Brooks]

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Race to claim your complimentary Chevy collectible!
http://click.topica.com/caac2NWbz8Qcsbz9JC9a/PermissionData
-------------------------------------------------------------------

William,

Generally white silicone RTV is compatible with the tedlar backskin. Shell
will have a preferred model number of silicon if you want to get really
technical about it, but I'm not sure there is a lot of difference. The key
is to get it covered up sooner than later so that moisture can't get in. The
other concern is damage to the cells and wiring. That should be tested
before you go to much trouble fixing the backskin. 

Testing a module at power can be a little tricky. Ideally, without an IV
Curve tracer, I would replace it in a circuit with a bunch of modules
connected to an inverter, test the power and irradiance before replacing the
module, then replace and retest the power and irradiance. If the power is
close, that is a good sign.

An easier test is to short circuit the module and shade two of the three
strings separately. Shell 72V modules are wired in a strange way--the two
outer rows are in series, the two left inner in series and the two right
inner in series. To test two at a time you have to: 1.) test outer and left
inner, 2.)test outer and right inner, 3.) then test both inner sets). Full
short circuit current should be available for each of these tests. If the
current drops significantly on any of these tests, either you shaded all
three strings inadvertently or you have a bad string.

That was a short and probably confusing description. If you have any
questions let me know.

Bill.

-----Original Message-----
From: William Miller [mailto:wrmiller at slonet.org] 
Sent: Thursday, January 06, 2005 10:12 AM
To: RE-wrenches at topica.com
Subject: Repairing module back [RE-wrenches]

Friends:

We have in stock a Shell module that has a back that was scraped by 
fork-lift forks somewhere in transit.  I'd like to repair this module and 
offer it to a client that could really use it.  Does anyone have experience 
in repairing the back skin of a Shell module?  Any advise is appreciated.

Thanks again to all of you and to Michael Welch and HP for this forum.

William Miller

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Like music?  Get a CD player on us. Click here.
http://click.topica.com/caac2NUbz8Qcsbz9JC9f/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
--^----------------------------------------------------------------