Here's an update from our discussion in the
Generator post.
List of those who helped with the manual labor:
Scott Johnson
Adam Ligon
Jason Mauldin
Mike Whitney
Carl Fisher
Donnie Barnes
What we found:
Peak load of our system is around 20Amps, with a continuous load of just over 10Amps. The entire load was being supplied with a single 14 gauge wire that was spliced into the bus wiring. The grounds on each of the power strips were 14 gauge household wiring, with one of the grounds wedged between two pieces of metal.
We also found that the P/A system needed rewiring and there was a short in the wiring to the rear speakers.
What did we do:
We upgraded the wiring to the "Wing nut power strips." It is now 6 gauge wiring fed directly from the twin 950 CCA bus batteries (rigged in parallel). We upgraded the grounds to a high quality 10 gauge wire on each side. We also ran the wires under the bus so there is no longer a overhead wire to fall on people. The power strip on the passenger side of the bus was removed with only the cigarette lighter plugs remaining. The power strip on the driver's side, is now switched with a small LED indicating the power status. All wiring is fused through a 40 Amp Fuse, located inside the battery box.
Our test device was the box fan plugged into a power inverter. Originally we would register a minimum 1 volt drop just by turning the fan on low (12.6 V dropped to 11.5 V). With the new wiring we see a 0.2 to 0.3 V drop in the same conditions. We can run the fan on high and stay around 12 volts. We found that with the new wiring, all three power inverters function properly with the box fan. (The laptop was not available for testing.)
Additionally, we identified one bad "spare" battery, that has already been recycled at Advance Auto. We also used a fancy tester and determined that the two big bus batteries and alternator are all fine. The remaining "spare" batteries also tested well and will remain in the bus for the time being.
Finally, the speaker wiring was cleaned up to get rid of a short to ground, and to ease the load on the amplifier.
What should we do:
At this point, if we did our math right, the two hard wired batteries in the bus should be good for about 20 hours of run time with all our gear (at peak load). That number is plenty for a one day event, maybe too close to reserve for a 2 day event.
Scott gets credit for putting most of this info together.
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