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Setting your Trace Auto Gen Start Parameters - davidbrady - 11-09-2018 20:12

I've been drydocking for two weeks. The auto start feature of the Trace SW4024's is factory default set as follows:

24hr: 24.6V
2hr: 23.6V
15min: 22.6V

The generator will start if the battery voltage is below any of the above three parameters for a time greater than that above. The problem is these values will allow your batteries to discharge far below 50% before the generator starts.

Here are the SOC vs OCV (open circuit voltage) values for the Lifeline AGM:
60%: 24.6 VDC --- Trace 24hr genny start timer begins
50%: 24.36
40%: 24.12
30%: 23.88
20%: 23.64 --- Trace 2hr genny start timer begins
10%: 23.4
0%: <23.16
-- Trace 15min genny start timer begins

The problem I've been seeing is the batteries are being discharged to well below 50% and as low as 20% before the generator is auto started. Turns out the default factory generator settings aren't suitable.

If the discharge rate is between 10 and 20 DC amps, which is our expected load when not running air conditioners, then in my case with an 800 A-hr battery bank, the batteries will be discharged to 50% in 20 to 40 hours. This doesn't line up well with the factory auto genny start parameters. Say we're in the middle at an average 15A DC draw. The 24hr timer will begin at 60% SOC which will be after 21 hours. When the timer expires 24 hours later my battery bank is well below a 20% SOC which is terrible for the longevity of AGM's. What happens in my case is that when the 24 hr timer is around the 20 hour point the 2 hour timer kicks in and the batteries start at a SOC slightly below 20%, which is still bad.

The matter is even worse if you're using a battery which isn't quite as high performance as a Lifeline such as an East Penn. These batteries all have SOC vs OCV values which are a good 0.1V above the Lifelines which means the default Trace auto generator start timer parameters will leave these batteries even further discharged.

The answer is to configure you generator start timers to start at higher battery voltages. I view the 24hr timer as a no load genny start parameter allowing the batteries to be topped up every now and then during periods of non use. The 2hr timer is the one I consider to be the most effective for our typical use case. The 15min timer is for cases of heavy draw, air conditioners for example, where you want the generator to start almost immediately. I have my auto gennerator start configured as follows:

24hr: 25.0V
2hr: 24.6V
15min: 23.6V

The important change is bumping up the 2hr voltage to the battery's 50% state of charge voltage level.


RE: Setting your Trace Auto Gen Start Parameters - cubeman - 02-01-2019 21:56

David, As you and the other BB past owner can imagine this Prevost is like starting all over . So our coach is a 98 would these parameters you speak about be the same for our 98 also ? I sure as h... do not want to cook the brand new AGM Batts . Thank you in advance ,and Yes David I'm back on the needy list , lol I just hope you have some time for these newbie question with you busy schedule, as I'm sure 4 growing school age children are keeping you busy my friend Smile


RE: Setting your Trace Auto Gen Start Parameters - Ernie Ekberg - 02-02-2019 10:10

where are you guys now, Al? We have a place 20 miles west of Weatherford that you all came to- its in Mineral Wells up high on a hill with a view of the valley below


RE: Setting your Trace Auto Gen Start Parameters - davidbrady - 02-02-2019 14:02

Al,

Most Vantare owners use the attached settings. They're pretty close to the Trace default settings. The attached is a good starting point:


RE: Setting your Trace Auto Gen Start Parameters - cubeman - 02-05-2019 22:22

No Ernie , we are still learning about the new coach here in Fla , but do plan to hit the road soon and head west . All I know is it is a good thing there is a Ocean cause I want to drive this baby , lol . We will be sure to look you up when we get out there Ernie and thank you for the offer .

David, Thank you for the Trace info . We practiced some dry camping today and even without realizing , the air units are so quiet , that one was on for a while and the genny never came on .

But this evening when we connected the electric the Genny came on after 20 or so minutes ? I hope to get a answer on that one in the morning when I talk to Richard here at the old Parliament . Does anyone have any ideas what could be going on ? The only way I stopped it was to turn off the auto start from the inverter.


RE: Setting your Trace Auto Gen Start Parameters - cmillsap - 02-06-2019 13:18

(02-05-2019 22:22)cubeman Wrote:  No Ernie , we are still learning about the new coach here in Fla , but do plan to hit the road soon and head west . All I know is it is a good thing there is a Ocean cause I want to drive this baby , lol . We will be sure to look you up when we get out there Ernie and thank you for the offer .

David, Thank you for the Trace info . We practiced some dry camping today and even without realizing , the air units are so quiet , that one was on for a while and the genny never came on .

But this evening when we connected the electric the Genny came on after 20 or so minutes ? I hope to get a answer on that one in the morning when I talk to Richard here at the old Parliament . Does anyone have any ideas what could be going on ? The only way I stopped it was to turn off the auto start from the inverter.


Al,

I'm guessing that you almost depleted the house battery bank to the auto gen set point while you were practicing dry camping, especially if you were running AC units. When you plugged in the inverter/chargers were not able to charge the battery bank fast enough to prevent further discharge at which point the Auto Gen did what it is supposed to do and started the gen to help recharge the batteries. At least you know that the auto start is working properly.

Al, you know the routine, it's no different than on you LXI. How long it takes before your batteries discharge to the point of activating your auto start depends on the condition of your batteries and the load you are pulling out of them. How old are you house batteries? The older they get the more likely they are to discharge more quickly.


RE: Setting your Trace Auto Gen Start Parameters - cmillsap - 02-06-2019 13:37

(02-05-2019 22:22)cubeman Wrote:  No Ernie , we are still learning about the new coach here in Fla , but do plan to hit the road soon and head west . All I know is it is a good thing there is a Ocean cause I want to drive this baby , lol . We will be sure to look you up when we get out there Ernie and thank you for the offer .

David, Thank you for the Trace info . We practiced some dry camping today and even without realizing , the air units are so quiet , that one was on for a while and the genny never came on .

But this evening when we connected the electric the Genny came on after 20 or so minutes ? I hope to get a answer on that one in the morning when I talk to Richard here at the old Parliament . Does anyone have any ideas what could be going on ? The only way I stopped it was to turn off the auto start from the inverter.


Al,

I'm guessing that you almost depleted the house battery bank to the auto gen set point while you were practicing dry camping, especially if you were running AC units. When you plugged in the inverter/chargers were not able to charge the battery bank fast enough to prevent further discharge at which point the Auto Gen did what it is supposed to do and started the gen to help recharge the batteries. At least you know that the auto start is working properly.


RE: Setting your Trace Auto Gen Start Parameters - cubeman - 02-06-2019 14:45

Chuck , here is what I found out about this . The Genny is the primary source of Electric on a Trace. So when I plugged in the Batteries were low as you said and the invertor sent a message to the Genny to help out . So the Genny started up.
So I took the genny auto off line and all was fine in the morning and the batts are now in float charge . I was able to prove this by resetting the auto Genn to on again and all is good . Man is this a cool set up .

Next I need to review what David said and check the setting on the inverter so I can be sure these new Lifeline batts do not become toast . Thank you for responding it is the only way we all can learn and benefit I believe .


RE: Setting your Trace Auto Gen Start Parameters - davidbrady - 02-06-2019 22:31

Al,

The generator will start upon either of the following circumstances:

1) The AC load is higher than the "Set AC Load Amps" setting under menu 12, "Generator Auto Start Setup".
This excessive amperage load needs to sustain for longer than the "Set Load Start Delay min" under menu 12.

2) The DC Battery voltage drops below the 2 hour, 15 minute, or 30 second voltage settings set in menu 12.

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!


RE: Setting your Trace Auto Gen Start Parameters - cubeman - 02-07-2019 09:36

David, I always need to hear something 2x before I understand and now you have in writing described exactly what Rick told me yesterday ,lol Now knowing and doing are 2 different things hahaha

I will tell you on a side note . I knew Benn C for many years but owning the bird our paths did not cross much , but after doing some reading on Prevost sites all I can say is what a loss to our coach world Benn is . I think in a little way it opens my eyes to my value to my family , beyond al the money I still provide lol