[RE-wrenches] Out Back FM-80 Problem

[Howie Michaelson]

Hey Dave,

I had a very similar experience (with the Apollo) with almost an identical
array (190's on 3 Pole Tops).  After the Apollo smoked 5 times I finally
stopped hitting my head against the wall and switched to the FM80 about
1.5 years ago.  The FM80 has worked well since until today, when it went
into a strange mode (as reported by the client).  In full noon sun, it was
registering that it was in "Bulk" but had an array voltage of 80+ volts
and a current of 60 watts.  Given history at this site (faulty FNDC which
I just upgraded to the new firmware last month and the series of Apollo
failures) I'm hoping that it had to do with the owner leaving it in a
history logging screen last night which confused the system.  I believe
I've seen some odd behavior when the Mate is left in some metering or
programing screens.  As soon as I had the owner scroll through some
screens, the FM80 appeared to be operating properly again.  I'll let you
know if this system continues to act poorly.

I don't know of any circumstances where the FM80 stayed in absorb too long
(this is a good size battery bank - 48 volt KS-33's 1766 amphrs, and a
higher demand house), but I will watch out for this.  I have heard from
Outback and others that they've had FM80's lockup when coupled with a
Xantrex SW system, but no noise about this happening on a complete OB
system.

Howie
-- 
Howie Michaelson
NABCEP Certified Solar PV Installer™

Sun Catcher, LLC
Renewable Energy Systems Sales and Service
VT Solar & Wind Incentive Program Partner
http://www.SunCatcherVT.com
(cell) 802-272-0004
(home) 802-439-6096


On Mon, April 27, 2009 9:06 pm, David Palumbo wrote:
> We have an off grid system experiencing charge controller issues. 3.24kW
> PV
> array (18) Evergreen ES-180's in (6) strings of (3) modules in series.
> Approximately 77 VDC Vmp, 60 Amps typically highest charging amps into a
> 33.6kWh (rated storage) 48 volt battery bank. Charge controller originally
> was an Apollo T-80 that never worked correctly (lots of various issues, we
> ended up trying three different Apollo's before the homeowner wanted us to
> try another controller). We went with a tried and true Out Back MX60 as
> the
> 80 Amp Flex was not available yet. We knew the MX 60  was outside it's
> recommended PV array capabilities but we needed to get the client's PV
> system charging the battery bank ASAP. We planned on upgrading to the
> FM-80
> when available.
>
>
>
> The MX-60 worked flawlessly for several months until it failed to control
> absorption charging. It would allow the batteries to charge at bulk
> voltage
> (58.8) for hours with out switching to float (54). Absorption time was set
> to two hours. Resetting and reprogramming did not resolve this situation
> and
> the batteries were being overcharged when a couple of sunny days  were
> strung together.
>
>
>
> We swapped in a new FM-80 controller on April 2nd and it worked perfectly
> until today. It was a sunny day and the FM-80 was in absorption mode by
> noon
> time. The homeowner noticed at 2:30pm that the FM was not in float as it
> should have been. It was a typical sunny day with no big loads on. The
> homeowner reported that the FM-80 was repeatedly going through a 6 minute
> cycle. Snooze for 5 minutes, wakeup 5 seconds, tracking 10 sec, bulk 30
> sec,
> absorb charge 20 sec, and back to snooze where it began another identical
> cycle. The batteries were 100% charged by 2:000pm, the battery voltage was
> at 53.5VDC (two OB VFX3648's ON powering lights and drawing 5 amps DC)
> when
> the FM-80 was not in bulk, or absorb charge. When in bulk charge the PV
> amps
> (35A mid afternoon, warm day) were connected to the battery bank the
> battery
> voltage climbed back up to 58 volts quickly. The "tech" we called at Out
> Back was not very helpful, "never heard of this situation" and tried to
> blame it on poor battery connections,  he could not understand why the
> battery voltage would be 53.5V with a 5 Amp load and then 58 volts 30
> seconds later when 35 amps were charging into the batteries on a 100%
> charged battery bank.
>
>
>
> Anyone else had an issue like this? Any advice?
>
>
>
> Thanks,
>
> Dave
>
>
>
> David Palumbo, President
>
> Independent Power LLC
>
> 462 Solar Way Drive
>
> Hyde Park, VT 05655
>
> NABCEP Certified
>
> www.independentpowerllc.com
>
>
>
>