Sol-Ark: how to turn generator OFF?

[tve]

I have a Sol-Ark 15k with a generator that is enabled using the std Sol-Ark gen signal output/relay. The Sol-Ark turns the generator ON when the battery SoC drops below a certain %. It seems it only turns it off when batteries are full? Can't quite tell from the manual.

How can I turn the generator off explicitly, either using the control panel or modbus commands? I had the generator come on at 6am due to power outage and batteries running down but once the sun came up the solar was sufficient and the batteries back up a good percentage above the gen threshold, so I wanted to turn the generator off to save gas. Can't do it.

I tried disabling gen-charge: no effect, disabling gen-signal: sol-ark turns gen off and then back on less than a minute later.
Anyone have any info?

 

[dreancestere]

If you don't use Time of Use settings, the generator will turn on when the battery reaches the level you specify in the Settings > Battery > Charge > Start (V or %) box. It will run until the battery is full and then shut down. If you want to shut it down at a different level, you'll need to turn on and set up Time of Use settings on the Settings > Limiter tab. Check the Charge box for all periods where you want the generator to be able to charge. With that box checked, the level in the Batt column will be the level to which the generator (or grid) will charge.

Time: Programable time intervals over a 24h period. All time slots MUST follow chronological order and must be programmed.
Power(W): Sets the maximum discharge rate of the battery during the corresponding time slot.
Batt: V or % used to specify a lower discharge limit or upper charge limit whenever “🗹 Charge” is enabled. Grid-tied systems
will not allow TOU to discharge lower than “Low Batt V/%”. Off-grid systems allow TOU discharge down to “Shutdown V/%”.
🗹 Charge: During the hours selected, it is allowed to charge batteries from an external AC source up to a programmed voltage or
%. If the external AC power source is a generator, the “Start V” or “Start %” condition must be fulfilled first. If available, the solar array
will always charge the batteries at 100% regardless of “🗹 Charge” in TOU.
🗹 Sell: Allows batteries to discharge and sell power to the grid at the programable “Power(W)” rate. “🗹 Grid Sell” MUST be enabled.
Do NOT enable “Charge” and “Sell” at the same time

EDIT: There's a Time of Use (TOU) Application Guide here:

Knowledge Hub

Use the Sol-Ark® Knowledge Hub to download product data sheets, certifications, installation guides, wiring diagrams, and more.

www.sol-ark.com

which explains TOU much better than what's in the manual.

 

[tve]

I'm a bit confused by the Sol-Ark description about the charge checkmark. In that TOU app note it says:

When using TOU settings off grid with a 2-wire auto start generator,
with the Charge boxes checked, the generator control relay will open the circuit to shut down the
generator as the battery SOC reaches the Batt setpoint. Generator start will still follow the charge
setpoints (Batt Setup menu → Charge) not any TOU settings despite the Charge checkboxes being
checked. All Charge checkboxes need to be checked to ensure the generator could turn on any time slot
to charge the battery if needed.

Does this last sentence imply that for time periods where "charge" is not checked the inverter will let the batteries run dead and power go out instead of turning on the generator (if grid is dead)?

 

[dreancestere]

From where I think you're looking in that document, if you go down a couple of sections to "Off-Grid: Precise Generator Control to Conserve Fuel," it says:

The battery will always discharge down to the Shutdown %/V (Batt Setup menu → Discharge) while off-grid.

I've no actual experience with that, but I'm assuming that also applies in an On-Grid situation when the grid is down. EDIT: I'm also assuming that generator charging will kick on at the Batt Setup > Charge > Start levels (which should be above the Shutdown level) because of the sentences surrounding the above quote:

The Batt value will depend on preference since this is the cutoff for generator charging.... In the above example, the generator will cutoff at 60% battery SOC.

I'm making a lot of assumptions here, but I assume they're talking about the generator cutting off when it charges the battery UP to the level specified in the TOU Batt setpoint.

So, with the Charge box unchecked, my take on it is that in an off-grid/outage situation, it will allow the battery to be drained all the way to the Shutdown level unless the generator Start value is reached first. At that point, the generator kicks in and charges up to the TOU Batt setpoint. In an on-grid situation, the TOU Batt setpoint is a floor, so the battery won't discharge down past that.

 

[robby]

I don't have a generator connected but if it works like everything else in TOU then your answer is right.

 

[rvsolarphd]

I also found the TOU documentation confusing, so I did an experiment and wrote up a white paper. I've attached it here in case you find it useful.

 

[Pooya_Sol-Ark]

I'm a bit confused by the Sol-Ark description about the charge checkmark. In that TOU app note it says:

Does this last sentence imply that for time periods where "charge" is not checked the inverter will let the batteries run dead and power go out instead of turning on the generator (if grid is dead)?

The answer to your question is yes. If the battery discharges below the Gen Start value during a time that does not have the charge box selected, assuming you have time of use on, the battery could discharge down to a state of charge that will trigger the inverter to shut down because the generator will not turn on.

 

[SolarFlares]

I also found the TOU documentation confusing, so I did an experiment and wrote up a white paper. I've attached it here in case you find it useful.

This is excellent. I'll be sending this to everyone who asks a question about the solark TOU settings. Only thing additional that might be helpful is how the generator settings interact with TOU for people off grid or people with grid tie but the grid goes down.

 

[rvsolarphd]

Thank you, I'm glad you found it helpful. Thank you for taking the time to tell me that.

I also have a companion YouTube video of the process as well, but I'm not sure about the forum rules, if I'm allowed to self-promote / cross-post. I'll ask here....is it OK for me to post a link to my YT channel in this case? Thanks in advance.

 

[DGSmooth]

I also found the TOU documentation confusing, so I did an experiment and wrote up a white paper. I've attached it here in case you find it useful.

Very good indeed. Can the TOU, in an off grid application, be used to limit the generator? As in, I want the generator to come on when batteries get low enough, but I don't want the generator to charge them completely, as I will likely have solar charging within a couple hours.....

 

[DGSmooth]

I also found the TOU documentation confusing, so I did an experiment and wrote up a white paper. I've attached it here in case you find it useful.

 

[offgridandy]

I have the same circumstance with my Victron Multipluss11. Off grid with PV and WT and LPG gen set. I use a LV setting to trigger the gen start relay. Once started from that trigger it is virtually impossible to manually off the genny. Victron will keep trying to start the genny until the condition that triggered the gen start is satisfied.

Usually I don't worry about it as, if the PV come on whilst gen set is running the gen charge time is reduced as the battery is getting DC from the PV as well so the battery is charging faster.

However if I know that "big wind" is forecast and the battery V is getting low the day before; I may then manually start and run the genny for a couple of hrs to give a top up. Then when the wind rises I can manually "off" the genny and leave the WT/PV to carry on charging.

I am told by a Victron guru that it is possible to override the auto start signal to the but I can't be arsed to dig that deep into settings.

 

[Oldphile]

Very good indeed. Can the TOU, in an off grid application, be used to limit the generator? As in, I want the generator to come on when batteries get low enough, but I don't want the generator to charge them completely, as I will likely have solar charging within a couple hours.....

When off grid the SOC values in TOU are the SOC at which charging from generator stops.

 

[DGSmooth]

When off grid the SOC values in TOU are the SOC at which charging from generator stops.

That's what I would have thought, but it doesn't work that way. I had the TOU battery value at 53V, as soon as I turn on TOU with that setting, it will actually drop the voltage down to 53V (if its above), and hold it there, and continue to run generator. If the current battery voltage is below 53V, it will charge up to 53V, then same thing, hold it there indefinitely and generator keeps running. Maybe has something to do with the "charge" and "sell" check boxes in the TOU setup?

 

[Oldphile]

That's what I would have thought, but it doesn't work that way. I had the TOU battery value at 53V, as soon as I turn on TOU with that setting, it will actually drop the voltage down to 53V (if its above), and hold it there, and continue to run generator. If the current battery voltage is below 53V, it will charge up to 53V, then same thing, hold it there indefinitely and generator keeps running. Maybe has something to do with the "charge" and "sell" check boxes in the TOU setup?

Is your generator already running before you turn on TOU?

 

[rvsolarphd]

I am told by a Victron guru that it is possible to override the auto start signal to the but I can't be arsed to dig that deep into settings.

So, I don't know enough about Victron to give you a software based answer to this question, but what about putting a light switch in series with the two-wire start to the GenSet. I think that would give you a way to manually override the signal to the genset, in terms of turning it off when Victron is trying to run it. If you set up a couple of three way switches, I think you could also manually override it and turn it on, but I'll have to think about that...

 

[DGSmooth]

Is your generator already running before you turn on TOU?

no generator off

 

[offgridandy]

So, I don't know enough about Victron to give you a software based answer to this question, but what about putting a light switch in series with the two-wire start to the GenSet. I think that would give you a way to manually override the signal to the genset, in terms of turning it off when Victron is trying to run it. If you set up a couple of three way switches, I think you could also manually override it and turn it on, but I'll have to think about that...

Even if you interupt the relay signal, Victron still considers the "start" condition to exist, therefore Victron still keeps powering the relay and when the "light switch" is reset to allow auto start, Victron fires up the relay again.

 

[Oldphile]

Is your generator already running before you turn on TOU?

no generator off

as soon as I turn on TOU with that setting, it will actually drop the voltage down to 53V (if its above), and hold it there, and continue to run generator.

I don't understand. When did the generator start?

 

[rvsolarphd]

Even if you interupt the relay signal, Victron still considers the "start" condition to exist, therefore Victron still keeps powering the relay and when the "light switch" is reset to allow auto start, Victron fires up the relay again.

I agree with you that Victron will continue to set the relay until the condition changes. I was thinking of a solution to the example you gave of having both PV and GenSet charge at the same time (your "Big Wind" example above). The switch would let you manually override the generator demand signal when PV was charging.... Apologies for not be clear in my typing....

 

[DGSmooth]

I don't understand. When did the generator start?

it starts when the voltage gets down to the trigger point, 49V. but then it just runs forever, even once voltage is up to the set point, and panels are producing more than the loads. this is my system right now:

 

[Cmiller]

Sol-Ark's gen start relay is, quite frankly, crap! We have a job right now that we are using the gen start relay, and it is hit or miss on whether the gen will even start. Sometimes it does, sometimes it doesn't....

I have been harping on this to Sol-Ark for literally years!

@Pooya_Sol-Ark Will you guys ever have a proper auto start menu?? I wish I could get someone from Sol-Ark to actually listen and do something about this!! We literally use Victron BMV-712 battery monitors on 99% of our Sol-Ark setups that have a gen that auto starts, all because of this issue with the start relay not being dependable and/or having practical settings!

TOU should not have anything to do with gen start! Ever! TOU is for grid interactive use! Having TOU tied into the gen start/stop severely limits options to use TOU and gen start side-by-side!

Edit to say: It seems that the "gen signal" and "grid signal" need to not be both enabled. Whichever is enabled will trigger the relay. (Most of the time.) Also, the gen start and grid start values cannot be the same, or the relay will not trigger. Just figured I would edit to say this, in case someone can benefit from this knowledge.