Use grid as a generator on Sol-Ark 15K GEN input? Possible?

[axum]

This is just a thought exercise, but I've been wondering whether it would be possible to use the grid as a backup generator for the Sol-Ark 15k, meaning: is it possible to connect the grid to the GEN input? Would the Sol-Ark automatically start drawing power from the grid when the batteries need charging (if properly configured)?

The reason I've been pondering this idea is because our grid voltage is very unstable, regularly dropping to 108 volts during peak hours (we live in the "woods" and there's a 300 feet feeder from the transformer to our house - not ideal)

 

[DIYrich]

Easier to use version 2 of the chargeverter to use Grid as backup.

 

[axum]

Easier to use version 2 of the chargeverter to use Grid as backup.

I have one, but it's loud as a jet engine. It can be heard from the opposite side of the house

 

[DIYrich]

The problem is: as soon as it connects the gen port, your house will follow the dirty grid power.

Two options to the screamer fans are:
1) separate large inverter to charge; or
2) build a diy chargeverter with multiple chargers (to keep the heat down) and quiet fans.
Post in thread 'DIY 'Chargenectifier'' https://diysolarforum.com/threads/diy-chargenectifier.56329/post-1309984

 

[1201]

This is just a thought exercise, but I've been wondering whether it would be possible to use the grid as a backup generator for the Sol-Ark 15k, meaning: is it possible to connect the grid to the GEN input? Would the Sol-Ark automatically start drawing power from the grid when the batteries need charging (if properly configured)?

The reason I've been pondering this idea is because our grid voltage is very unstable, regularly dropping to 108 volts during peak hours (we live in the "woods" and there's a 300 feet feeder from the transformer to our house - not ideal)

Why not just connect the grid to the grid input?

 

[Skypower]

If the voltage is habitually low you could use a buck/boost transformer. They are not too terribly expensive. This type of transformer is relatively efficient but it also doesn’t clean up anything(non isolated). All it does is boost the power by the amount of the “tap” wiring selected. The bad, is if the incoming voltage goes up to normal, your output might be too high.

 

[Skypower]

Not an endorsement or necessarily a recommended size, just an example.

 

[axum]

Why not just connect the grid to the grid input?

Because the inverter syncs with the grid. If the grid is at 108/216, so will the inverter output

 

[axum]

The problem is: as soon as it connects the gen port, your house will follow the dirty grid power.

Will it though? If that would be the case, the inverter would occasionally back-feed to the GEN output (when a large load drops off), which is a big no-no for generators.

 

[DIYrich]

Will it though? If that would be the case, the inverter would occasionally back-feed to the GEN output (when a large load drops off), which is a big no-no for generators.

It is drawing large amps from the gen input when connected. If a large load drops, it is less the inverter draws until it adjusts. It won't backfeed.

 

[axum]

It is drawing large amps from the gen input when connected. If a large load drops, it is less the inverter draws until it adjusts. It won't backfeed.

With the grid connected, and grid sell disabled, there's always a little bit of backfeed when no power is drawn from the grid (load 100% covered by solar or batteries) and a load drops off (like an electric water heater). There's no way to prevent that because of how a hybrid inverter works.
If the inverter would "follow" the GEN input in the same manner, it would behave the same if there is no draw from the GEN input and a large loads drops off. That's why I doubt that the inverter will sync frequency and voltage to the GEN input.
It may be worth trying just to find out.

 

[DIYrich]

If the inverter would "follow" the GEN input in the same manner, it would behave the same if there is no draw from the GEN input and a large loads drops off. That's why I doubt that the inverter will sync frequency and voltage to the GEN input.
It may be worth trying just to find out.

Yes, but....

The SA would connect to gen port only when it needs to charge the battery. It would not be connected in the zero draw scenario.

 

[dreancestere]

Another thing to be aware of is the GEN port is limited to 80A continuous.

EDIT: Also, I only have a teeny-tiny bit of experience with my generator on the GEN terminal, but in my limited testing, I could only get the generator to turn on with both the Grid and PV off. I don't know if that's because the PV was providing enough power to handle the load or if there actually has to be no input on both those terminals for the GEN terminal to activate. So, that might be something else to think about if the grid is connected to the GEN terminal. Perhaps someone with more experience with a generator (or an AC Coupled system) on the GEN terminal can put that to rest.

 

[mwk1000]

In normal either GEN OR Grid never both it would just see the AC power as it would a genset BUT with a 100 amp breaker limit as mentioned 80A usable. So you have to judge if your going to pull more and blow breaters - ug. If I have to guess normal gen mode is setting the AC Freq (sync) and a lousy source might not do well with the Inverter making AC ( it would normally be the source setting the AC Freq when the grid is down (UPS mode )) when a gen is running that has to be the source since you cant tell it to "sync" with anything...

Micro Inverter mode allows grid and gen ports to connect AT THE SAME TIME so anything on the gen side MUST be able to align its AC Freq to the running grid or running inverter... I run this way. The gen port is connected 99.5 persent of the time and I charfe my batteries from "the grid" since that is what my PV power looks like on the gen port. The caviat being that you cant separate real grid from PV so TOU I have to set charge windows and charge amps to maximize the solar use. I like it the grid fills in and the charge cycles are nice and regular. Picture shows this in action . Winter sucks so I start to charge early to be done before 11am when the rates triple ( I signed up for this plan very low rates then 11am-7pm very high). See the meager solar coming up late and low dec.jan snow and clouds Red(Grid) is filling up Brown(battery) then battery runs the whole house for 8 hours. The grid will "chip in" lowering the grid charge pull - then lowering the battery usage in the peak window. I the spring - fall the power is large over 6k by 7:30 so I push back the charge start and bump up the charge amps to be done by 11 still then the batteries are not needed until sunset .

I have no issues with overload because I set-up a separate smart meter that controls the output of the AC-connected PV modbus fast ( less than 1 sec )

ps. the chart is stacked so the totals are easy to see and the contribution from each. There a a single purple line that is the full load.

 

[bob monztr]

My Gen port won't open so I run into grid port, 9000w gen at 6200w I get 119.8 to 120.1 V at 59.88 to 60.12 hrz, turning off all surge loads should keep it smooth, with surges on I would get errors over under hrz, gfi's popping when it switched to float, don't forget a big note that says "FRIDGE!!!". Sorry I can't scope it but it seems super smooth to use.