[RE-wrenches] AC Coupled Magnum Issue

Thu Mar 7 15:07:59 PST 2013

Hi Allan,

In answer to your question: Yes, we're developing an AC side 4kW
diversion mode controller which allows temperature compensated three
stage charging for AC coupled inverter applications.  It is currently in
beta site testing.  

Brian Faley

Chief Engineer

Magnum Energy Inc.

2211 West Casino Rd

Everett, WA 98204

Ph 425-353-8833

www.magnumenergy.com

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Allan
Sindelar
Sent: Thursday, March 07, 2013 2:41 PM
To: RE-wrenches
Cc: Support
Subject: Re: [RE-wrenches] AC Coupled Magnum Issue

McAfee SiteAdvisor Warning

This e-mail message contains potentially unsafe links to these sites:

<http://www.siteadvisor.com/sites/athens-electric.com/?pip=false&premium
=true&client_uid=446795512&client_ver=3.6.0.187&client_type=IEPlugin&sui
te=true&aff_id=0&locale=en_us&ui=1&os_ver=6.1.1.0> 

http://athens-electric.com/

OK, a bit more:
The line diagram I was referencing was dated 5/1/2010. A later diagram
from a Powerpoint given at last year's NABCEP CE conference shows a
"MagNet" AC diversion controller. It allows AC diversion loads and
three-stage charging. No mention of temp comp.

Magnum needs to weigh in on this.
Allan

Allan Sindelar
Allan at positiveenergysolar.com <mailto:Allan at positiveenergysolar.com> 
NABCEP Certified Photovoltaic Installer
NABCEP Certified Technical Sales Professional
New Mexico EE98J Journeyman Electrician
Founder and Chief Technology Officer
Positive Energy, Inc.
3209 Richards Lane (note new address)
Santa Fe, New Mexico 87507
505 424-1112
www.positiveenergysolar.com <http://www.positiveenergysolar.com/>  

On 3/7/2013 3:00 PM, Drake wrote:

	Hello Wrenches,

	I had an unexpected glitch in AC coupling a Magnum 4024 PAE
inverter.  The system utilizes AGM batteries, which (according to
Concorde tech support) have a very strict upper voltage limit.

	The relay used to stop the current input from the direct grid
tie inverter, when battery voltage is high, is controlled by a
Morningstar Relay Driver.  The relay driver is set to shut off the
charge at 28.8 volts.

	The charger on the Magnum is set to charge the batteries to
28.6 volts.  

	The plan was to be able to charge batteries from the Magnum
without tripping the AC connection between the grid tie inverter to the
grid.  The Magnum should charge to 28.6 volts, 0.2 volts below the relay
driver's programmed trigger point. 

	There is one catch to using this approach. The Magnum inverter
has a remote temperature sensor in the battery bank. The relay driver is
not temperature corrected. Therefore, when the batteries are cold, the
charging voltage goes up in the Magnum.  This higher voltage trips the
relay controlled by the driver, and disconnects the grid tie inverter
from the grid.  

	I've played with the voltage set points, but the charge voltage
on the Magnum would be too low for good battery maintenance.  If these
were liquid electrolyte batteries, I'd crank up the voltage on the relay
driver.  Since they are AGM batteries, it doesn't seem like a good idea
to do that. 

	The work around for this at present is to; 

	*	Charge batteries at night in the winter 
	*	No problem is expected in the summer 

	The batteries are in an insulated box in a shed connected to the
house. The inside of the battery box has a screened hole that is
supposed to allow heated air into the box.  This vent doesn't keep the
batteries warm enough to prevent the problem. 

	Is there a temperature sensitive, voltage controlled relay or
diver available?  Has anyone used a temperature bulb with the relay
driver in a way that could solve this problem? Has anyone else come up
against this issue, and if so, what was your solution?

	Thanks,

	Drake 

	Drake Chamberlin
	Athens Electric LLC
	OH License 44810
	CO License 3773
	NABCEP Certified Solar PV Installer
	740-448-7328
	http://athens-electric.com/ 

	_______________________________________________
	List sponsored by Home Power magazine

	List Address: RE-wrenches at lists.re-wrenches.org

	Change email address & settings:

http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

	List-Archive: 
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

	List rules & etiquette:
	www.re-wrenches.org/etiquette.htm

	Check out participant bios:
	www.members.re-wrenches.org

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20130307/6dbaceaa/attachment-0003.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.gif
Type: image/gif
Size: 659 bytes
Desc: image001.gif
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20130307/6dbaceaa/attachment-0006.gif>