Setting your Trace Auto Gen Start Parameters

[davidbrady]

(05-19-2019 14:22)Jerry_94110 Wrote:  

(02-06-2019 22:31)davidbrady Wrote:  I'd check your inverter's menu 11, "AC Inputs" . The first menu item, "Set Grid Amps AC" is normally configured to 47A when connected to 50A shore power. This is one of the parameters that often gets changed. For instance, if your shore power connection only supports 30A you'll need to adjust this parameter downward to avoid tripping the shore power circuit breakers. If you forget to reset it to 47A when connected to a 50A hookup then the inverter will only draw 30A. If you have all 4 air conditioners running you'll draw more than 30A and the inverters will provide the excess from battery power. This will run down your batteries to the point where the generator starts due to the Low Battery Cutoff Setting, which are set in menu 12, "Generator Auto Start Setup". So, short answer: check your "Set Grid Amps AC" setting in menu 11. Clear as mud right! LOL!

Hi Dave, I am curious why "Set Grid Amps AC" is set to 47A and not 50A when you have 50A coming in?

Also, I went to charge up the batteries yesterday since the coach is stored with no electric. When I left it last Sunday the inverters were both in float and the batteries were at 26.6. When I arrived yesterday, the batteries were are 24.9 even though everything was shut down. It took 3 hours of generator time for both inverters to be in float and batteries read 26.8. I guess this is due to menu 10 "Set Absorption time" is set to 3:00? Since I am not using the coach and only top off the batteries would it hurt to reduce the absorption time to 2:00 hrs? I remember reading somewhere that absorption time is important.

Thanks,

Jerry,

Setting the shore cord amps AC to something less than 50A or less than 30A, depending upon shore power availability, is a time honored way to avoid tripping weak circuit breakers at the pole. Also, I think the Trace inverter uses average values instead of RMS values. Average values compute as 0.637*Peak whereas RMS computes as 0.707*Peak, this makes a 50A RMS value look like a 45A average value. It's much easier to do a running average than it is to do a running RMS calculation.

As far as the battery draining. Do you have the DC loads turned off at the big DC 12 and 24V cutoff switches? (When pulling these switches be sure to move them both at the same time). Do you have the two 250A input breakers turned off that supply voltage to your inverters?

When generator charging you can increase the charging amps in Menu 10 (Battery Charging). With my 840Ahr battery bank I often set my charging amps to 25A (AC) on both inverters to shorten the constant current charging interval. After this you still need the 3 to 4 hour Absorption time. Your batteries may have discharged more quickly because they weren't fully absorption charged. Absorption can be terminated when the battery charge current has dropped to 0.5% of it's amp-hour rating. For my 840 A-hr battery bank that's 4A DC, which looks like less than 1A AC and less than 0.5A AC per inverter. Make sure you're down to these levels using the Meters Menu to verify you're not terminating Absorption prematurely.