[RE-wrenches] Pulse 250 power center

[Christopher Freitas]

The normal UL DC rating on the Square D QOU breakers is 50VDC but that
is with a fairly high interrupt current (i.e. for battery/load
circuits).  As part of the UL listing process for the APT power center
the breakers were evaluated for use up to 100 VDC with low interrupt
current levels - i.e. PV arrays.  The switchover to the Heinemann
breakers was done for other reasons and they also allow higher open
circuit voltages - up to 165VDC.  

 

So - I would not be concerned about using the existing Square D QOU
breakers as long as the open circuit voltage of the PV array doesn't
exceed the 100 VDC level.  

 

Christopher

 

 

Christopher Freitas

Director of Research and Development 

OutBack Power Systems, Inc.

cfreitas at outbackpower.com <mailto:cfreitas at outbackpower.com> 

Tel 360 435 6030

Cell 360 202 4239

19009 62nd Ave NE 

Arlington WA 98223 USA

www.outbackpower.com <http://www.outbackpower.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, January 01, 2009 7:16 AM
To: 'RE-wrenches'
Subject: Re: [RE-wrenches] Pulse 250 power center

 

Bob and Joel,

Depends on the powercenter model. Only the oldest APT/Ananda models used
Square D QOU breakers for DC. APT's later units (the 4B) used QOU only
for AC, and used Heinemann CF for DC. By the time the brand was Pulse
all DC breakers were Heinemann (or maybe equivalent Airpax), and thus
rated 125V DC.

 

The bigger problem was that the later models (and other models too)
lacked sufficient breaker spaces; the 4B had 5. With 2 for PV input, 2
for PVGFP, and 1 for DC loads, that left no room for expansion.

 

By the way, what is the name of the most recent iteration of Pulse, that
followed Connect Energy? Just a few years ago, they were developing a
48V grid-tied with batteries inverter. I had also heard that they had
none of the earlier personnel, just the name and intellectual property,
and were to be approached very cautiously.

Allan

 

-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of robert
ellison

 

The better bet is the MPPT controller but keep in mind that the original
breakers are not rated for the series panel strings that we use now. The
Square D breakers are only UL rated for 50 volts not the typical 70 - 96
volts we see now.


Here's to a great new year,

 

Bob

 

 On Wed, Dec 31, 2008 at 1:26 PM, Joel Davidson
<joel.davidson at sbcglobal.net> wrote:

	Hi Allan,
	
	Good idea bypassing the old charge controller. I'll pass it on
to our customer.
	
	...and good memory. The Ananda people did the PV industry a real
service by making the first UL listed power center.


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