[RE-wrenches] Magnum: meter won't reset; Internal Bridge error

[boB Gudgel]

boB asked:

"Does this customer have another charging source besides a generator, like PV?"

Mick says:
No...that is unfortunate because the customer doesn't want to allow
the generator to grind away for the additional hours required for a full
recharge.


boB says:  That's certainly understandable...  I don't blame them for that !


Mick continues: They've been shutting the generator down when the Magnum display
shows 99%. If the client could win the lottery, renewables could be added but
job one has been to reduce their bill for diesel.


About the meter reset problem, boB says: "1) The return Amps must go below 2%
of the Amp-Hour setting for the battery bank (settings via the remote)."


Mick says:
The battery string is 400 amp hours, which also happens to be the
Magnum default. This setting pre-disposes the Magnum charger for a 120 minute
absorption period before shifting to float. 2% of 400 is only eight amps, so
I'll bet the Magnum unit is dropping into float before the DC amperage can
taper to the 2% level. I need to get my customer to confirm that as a possible
explanation why we're not getting the reset...if I can explain that in a fax.


boB replied:  Yes, Could be going to Float early.  Supposedly, the voltage-time curve
           and Amp-hours in vs. amp-hours out requirement should
	   pretty much finish it off.  I'd be interested to hear any comments on
	   that.  BTW, Brian Linari is the designer of the BMK in case
           anyone would like to go straight to the horse the source of course.

Mick says:
Note 1 to the Magnum engineers: Isn't 5% return amps a more common determinant
of full charge instead of 2%?


boB saith:  Forwarded to the engineers.  Hey, I know !  How about we make it adjustable !!
	    Now there's a concept !  Actually, if the inverter goes to float, the
	    return amps % raises up some.  It's sort of smart, in some ways.
            In fact, for sure, (OK, what I'm told), the higher the voltage,
	    the higher the percentage (up to a point, I'm sure)  2% is only
	    for lower than absorb voltages, which sorta makes sense.


Mick says:
Note 2 to the Magnum engineers: If the charger drops into float how about
allowing that to trigger a reset on the ah meter? In this installation, one
Magnum hand seems to not know what the other Magnum hand is doing...that seems
a shame when the ah meter is networked in with the inverter/charger.


boB bellows:  Yes, agreed.


Note 3 to the Magnum engineers: "Shift to float" based on "return amps" seems
better than a shift based on minutes. I realize that not all inverter
customers buy the meter option, but for those who do...it seems that the
networked aspect could deliver another customer advantage if the amp meter
could report the return amps and the charger use this information to decide
when to shift to float. Just wondering...


boB utters:  Yes, of course.  I hear that it is coming.


Thank you, boB, for helping me cut through the customer support muddle. I had
once before tried to get help from Magnum via email and I got no reply.

boB replied, saying:  Maybe the system thought it was spam ??  Doggone spammers anyway !
               They're screwing up the internet !

	     And, you're welcome !!


Mick Abraham, Proprietor
www.abrahamsolar.com
Voice: 970-731-4675

P.S. I also think my customer has some problem in his fairly new battery
string. After pushing the Magnum charger all the way to float, the Magnum ah
meter clocked only 137 amp hours of DC delivery before the inverter shut down
due to low voltage. I think I'll loan the client a PakTrakr voltage monitor
which can connect to each 6v unit all the way up the battery string, and we'll
look for anomalies. Maybe we'll find one zombie...


boB PS's:     Hmmmm...   OK. try and find the zombie, if it's there.  Either way,
                    noted and forwarded off to the engineers and zombies here.






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