C40's and SW's [RE-wrenches]

Tom Lane, Energy Conservation Services tom at ecs-solar.com
Wed Feb 5 17:27:09 PST 2003


there is the bleeding edge- the leading edge and the safe back side of the
wave - it is always more profitable to let the young pups experiment with
the front have of the wave so you do not get caught in the  undertow with
the guinea pigs  experiment on your  own fort or at the office  gator tom
----- Original Message -----
From: "Bill Brooks" <billb at endecon.com>
To: <RE-wrenches at topica.com>
Sent: Wednesday, February 05, 2003 4:42 PM
Subject: RE: C40's and SW's [RE-wrenches]


> Jay,
>
> With all due respect to the Outback folks, for grid-tied systems I would
not
> be so quick to toss my C-40s for a Max Power controller, whether MX-60 or
> SB50. The additional cost may or may not pay for itself over time and the
> reliability is an unknown. I don't think anyone has enough hard data to
make
> that blanket assessment.
>
> Our industry has been so quick to run like lemmings to the sea every time
a
> new idea or product comes on the market. I always like to ask the lemmings
> why they are running so fast, where they are going, and for what reason.
> They seldom can provide me with good information to join them.
>
> Bill.
>
>
> -----Original Message-----
> From: Jay Peltz, Peltz Power [mailto:jay at asis.com]
> Sent: Tuesday, February 04, 2003 6:30 PM
> To: RE-wrenches at topica.com
> Subject: Re: C40's and SW's [RE-wrenches]
>
>
> I think that any discussion of C-40's on large arrays, especially intertie
> is a moot point.
>
> Most interties are pretty large and so the use of a MPPT controller is
very
> cost effective and is any easy swap out.  ( especially as the MX-60 fits
the
> same KO's)
>
>
> In regards to the higher voltages equalling higher power, yes but I have
> never seen any change in the output of the SW with the higher input
> voltages.
>
> Peace,
>
> jay
>
> Peltz power
>
> ----- Original Message -----
> From: "Jeffery Wolfe, Global Resource Options"
> <jeff at globalresourceoptions.com>
> To: <RE-wrenches at topica.com>
> Sent: Tuesday, February 04, 2003 11:29 AM
> Subject: RE: C40's and SW's [RE-wrenches]
>
>
> > Bill,
> >
> > Although you're right that the C40 should never control, the point of
the
> > higher voltage settings is to make more power. We all know that the PV's
> > will put out more power at higher voltages, so setting the inverter
> higher,
> > for float, is better. We also need to balance this with battery high
> limits,
> > and the fact that you need a pretty significant "dead band" in the
control
> > setpoints between the C40 and the Trace, due to inaccuracies in the
> voltage
> > meters in both units. (Trace told me 1.5 V, I'm typically using about
1.0
> > V).
> >
> > The 53.6VDC default on the inverters is also on the very low side of
where
> > we're floating batteries, even on-grid, today. We're moving hotter, more
> > like 54.8 to 55.2. Batteries that float all year long tend to have
> sulfation
> > problems, and it seems that the hotter setpoints help reduce this.
(Along
> > with the little black boxes.) Couple this with the fact that on-grid
> higher
> > float voltages are going to produce more power, the case is made for
> setting
> > the floats about as high as the manufacturer's will let you. We do use
> bulk
> > mode, as it's good (IMHO) to bulk the batteries occasionally. So we set
> the
> > bulk up at about 58 VDC. This then pushes the bulks on the C40's up to
59
> to
> > 59.5, in order to provide as much dead band as possible.
> >
> > We've got three years on our double C40 / SW system, as well as several
> > others around the area. The low set points "work", but are not the best
> for
> > power production (remember, we all complain about power production on PV
> > systems), and are not necessarily the best for battery life.
> >
> > I do agree that the C40 float and bulk can be set the same, but it's
more
> > like setting the float to the same as a more typical bulk, rather than
the
> > other way around.
> >
> > I also always use a Fluke to set up the C40 (and any other controller).
I
> > never trust the little dials or displays. They can be wrong (on any
> > controller).
> >
> > Jeff
> >
> > -----Original Message-----
> > From: Bill Brooks [mailto:billb at endecon.com]
> > Sent: Tuesday, February 04, 2003 1:10 PM
> > To: RE-wrenches at topica.com
> > Subject: RE: C40's and SW's [RE-wrenches]
> >
> >
> >
> > Graham,
> >
> > I believe that bulk charging is meaningless in a grid-connected
> application.
> > Since the system is floated all the time, except during a power outage,
> the
> > focus is on the float settings. I would set the bulk timer on the
inverter
> > to 0:00 so it automatically goes to float. The default for the inverter
is
> > 53.6 Volts for float and I think that is fine for most lead-acid
> batteries.
> > The key is making sure the C-40 is set at least one volt higher. It is
> also
> > critical that all controllers and inverters have temperature
compensation
> > probes installed and sensing basically the same temperature.
> >
> > Finally, check the C-40 while operating to make sure it is not
> controlling.
> > By testing the voltage drop across the C-40 positive battery and PV
array
> > inputs, you can tell whether it is controlling. The voltage should
always
> be
> > below 0.75 Volts, otherwise it is controlling. It should only control in
> an
> > outage. Set the C-40 bulk at the same as the float, since the array
should
> > not be bulk charging the battery anyway. Bulk charging doesn't help a
> > battery that stays at float all the time. It can actually hurt a VRLA
> > battery by overcharging it if you allow it to bulk for more than a
> half-hour
> > or so. Hope that helps. Others may see it differently but I have over
four
> > years of grid-connected experience with my C-40s and SW.
> >
> > Bill.
> >
> >
> > -----Original Message-----
> > From: Graham Owen [mailto:graham at solarexpert.com]
> > Sent: Monday, February 03, 2003 9:01 PM
> > To: RE-wrenches at topica.com
> > Subject: C40's and SW's [RE-wrenches]
> >
> >
> > Dear Colleagues,
> >
> > I need some Wrench assistance with a PV service call, for the Xantrex
> > Power Module system (or power panel for that matter), you have to set
> > the C40 charge controllers and the SW inverter so that the inverter can
> > sell PV power to the grid without the controllers restricting current
> > into the inverter in the first place. I am trying to determine which set
> > of values works the best.
> >
> > Are these good figures?
> >
> > C40  bulk   56.0
> >      float   55.0
> >
> > inverter bulk  54.0
> >        float   53.2
> >
> > Thanks in advance!
> >
> > Graham
> >
> > P.S. Joel, I am working on finding your CPUC answers, I was working out
> > of town today.
> >
> > - - - -
> > 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
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
> - - - -
> 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 sbcglobal.net

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

TOPICA - Start your own email discussion group. FREE!
http://www.topica.com/partner/tag02/create/index2.html
==^================================================================




More information about the RE-wrenches mailing list