net metered system question [RE-wrenches]

[Bob-O Schultze, Electron Connection]

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>	The system has been programmed as follows:
>Trace bulk charge voltage 58.6, Abortion time 2 hours,
>Float Voltage 54.0 (I don't want to set this any higher because the battery
>box vent fans would stay on all the time as they are set to come on at
>54.4v).

David, you don't say what the "sell" voltage is programmed at. 
Assuming it is default at 52.8 (I think), what seems to be happening 
is very short power outages. Perhaps multiple ones-remember that the 
Trace will sense a 16mS outage. After an outage, the Trace will go 
into a bulk charge. That will put it off sell for at least the 
absorption time of 2 hours. Since the batteries are full anyway, this 
would allow the voltage to climb to the 60V (61.9 temp compensated, 
would make sense) level then drop to float @55.5 + during that 
period. Setting the absorption time to 0:00 would eliminate most of 
that.
Bob-O

>Pulse Charge Controller settings: Bulk 60.0 volts, Float 55.5 volts,
>Equalize automatically every 30 days to 61 volts.
>	Both the Trace and Pulse settings are temperature compensated.
>The temp comp differential has been running from 1v to 1 1/2 volts (for
>example temp comp volts 54.0, actual volts 55.2v.
>
>PROBLEM: It has been observed, on more than one occasion, (I have not
>re-visited the site yet so I have not personally checked things out yet, but
>a very competent technical person was relaying the info to me via phone
>yesterday),
>that the pv charge controllers were controlling the pv current at float
>voltage,54v temp comp, when observed. The sunlight was strong at that time
>so the sell back that should have been occurring was not happening. After
>the grid sell back was set up (Dec 2000) we had observed good performance on
>sunny days with the meter spinning backwards to the tune of 16 to 20 amps at
>120 volts on each SW4048.
>
>The system monitor (TriMetric) picked up some interesting data that shows a
>recent power outage that could explain at least part of the problem.
>Trimetric high battery voltage 61.9v (Equalized pv actual voltage), and a
>low voltage of 48.5v (this would have had to have been a grid power failure
I think).

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