[pvusers] Fried controller...

[william stewart <v_stewart@earthlink.net>]

I could use some experienced insight on two questions below.

I bought components for a gridinteractive (net metering), battery backup 
PV system with the primary components;
 - 50 Solarex Millenia 42w modules
 - Trace SW4048
 - Heliotrope Solpan 110 Power Fuse Center with CC120 48V
 - Concorde PVX-180T, qty 12

After installation and array checkout, we engaged the arrays at the 
Solpan, which showed 85v, no load (a rainy day, too).   Then we engaged 
the battery to controller CB, and the readings added were battery 
voltage 52.4 and charging amps 0.1.

We then turned on the inverter, with the technician starting to go 
through the menus.  After approximately a minute, the bulk light came 
on.  At the same time, the Solpan readout changed quickly, a CHARGED 
indicator came on, and then it stopped functioning, with a acrid smell 
of burned electronics in the air.  We opened the breaker from the 
battery to the controller and rechecked the wiring diagram and 
polarities; everything checked out.

QUESTION 1: What is the problem?  Are the components mismatched?  I 
realize a schematic would help fault isolate, but attachments are 
difficult here.

Now there appears to be two options going forward.

1. Install a "compatible" charge controller, such as a Trace C60, or
2. Let the inverter control battery charging, with a mercury 
displacement relay to protect the batteries if the grid goes out (as 
shown in manual).

QUESTION 2: Any pros and cons associated with these selections?  Do I 
really need PWM?  Can I take advantage of power tracking if I have 
batteries?

Thanks,

Will Stewart


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