Inverter protection [RE-wrenches]

[Jeffrey Wolfe, Global Resources]

Many "industrial control" systems have large notices on them "Warning, more 
than one power source. Multiple points of disconnection may be required."

This is what we have in most RE systems. Homeowners should NOT be going 
into these panels, any more than they go into their electrical panels.

The inverter frying incident is a little more worrisome. I hate to see a 
simple mistake or accident (bumping the trigger happy 250A disconnect) fry 
an inverter. Did it happen immediately, or was it off for a long time 
before the wind smoked the inverter?

I guess thought that basically you ran the mill with no battery load, 
inverter had insufficient load on it, and the power had to go somewhere so 
it made smoke. (I'm assuming this is not an intertie.) Do others agree with 
this analysis?

Only way to avoid that would be with some fancy automatic relay 
interlocking. I think signs are probably better.

Jeff

Jeffery D. Wolfe, P.E.
Global Resource Options, LLP
A Woman-Owned Vermont Limited Liability Partnership
4 Kibling Hill Road
P.O. Box 51
Strafford, VT 05072
802/765-4632
802/765-9983 (Fax)
global at sover.net
www.globalresourceoptions.com

----------
From: 	Doug McCorkle[SMTP:dmccorkl at sover.net]
Reply To: 	RE-wrenches at topica.com
Sent: 	Monday, December 04, 2000 7:23 AM
To: 	RE-wrenches at topica.com
Subject: 	Inverter protection [RE-wrenches]

I have a question for the expertise of this group.  We are in the final
throws of completing a system (2 racks of 4 ASE 300W modules on trackers 
and
3000W Whisper (I think), 2 Trace 5548s for 240V on a Trace Power Board,
about 2000 Ahr battery bank, 20Kw generator, purchased as a package from
Kiocera ("It will take an electrician only a few hours to get it up and
running!")).  The power inputs (PV and wind) are connected to the inverter
side of the 250A battery disconnects, which is our question.  It seems to
leave the inverter unprotected - you're able to isolate the batteries, but
to isolate the inverter you need to turn off the PV and wind input
separately.  This would seem to make sense, but it seems that an 
inattentive
or inadequately trained homeowner might easily turn off the battery main,
thinking they were disconnecting power to the inverter, when in fact the PV
and wind would still be powering the units.  We actually did this (left 
only
the wind connected), and one of the inverters smoked.  So, I would
appreciate any thoughts and/or remedies.
Doug McCorkle
Sunnyside Solar

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

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

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

To check out the other RE-Wrench participants:
 www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine:
 www.homepower.com

For info contact list moderator by email:
 michael.welch at homepower.com

___________________________________________________________
T O P I C A  http://www.topica.com/t/17
Newsletters, Tips and Discussions on Your Favorite Topics

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

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

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

To check out the other RE-Wrench participants:
 www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine: 
 www.homepower.com

For info contact list moderator by email:
 michael.welch at homepower.com

___________________________________________________________
T O P I C A  http://www.topica.com/t/17
Newsletters, Tips and Discussions on Your Favorite Topics