Help with growatt 5kw offgrid inverter (eu)

[Confusedcoconut]

Hi.
With the growatt spf5000es being a offgrid inverter am I right in thinking I need to have a rotary changeover switch to completely prevent any backfeeding into grid and run all AC through the growatt like so?

Then in the unlikely event I should need intensive power consumption the 5kw unit cannot handle I can turn off the AC isolator to prevent backfeed and change the rotary isolators position to feed the consumer unit and not the inverter?

(I'll be getting an electrician to do all final wiring and check it off)

 

[timselectric]

Hi.
With the growatt spf5000es being a offgrid inverter am I right in thinking I need to have a rotary changeover switch to completely prevent any backfeeding into grid and run all AC through the growatt like so?

(I'll be getting an electrician to do all final wiring and check it off)

No
This inverter can't back feed the grid.
And, the transfer switch is built in.

 

[timselectric]

Adding the external transfer switch is ok. It allows you to bypass the inverter for maintenance, if needed.
But, it's not required for a working installation.

 

[timselectric]

But, it should be located after the inverter.
To select either the grid or the inverter, as the feed for the consumer unit.

 

[Confusedcoconut]

Adding the external transfer switch is ok. It allows you to bypass the inverter for maintenance, if needed.
But, it's not required for a working installation.

Yes I understand it isn't needed for it to work. My thinking is if i had future issues with inverter it would be easy to bypass until fixed

 

[Confusedcoconut]

But, it should be located after the inverter.
To select either the grid or the inverter, as the feed for the consumer unit.

But then would it function as a bypass for the system as the mains would still have to go through the inverter regardless

 

[timselectric]

But then would it function as a bypass for the system as the mains would still have to go through the inverter regardless

Yes
You would turn the switch, and shut off the breaker feeding the inverter. Then, the inverter would be completely isolated from AC power.
The way you have it located, in the drawing. You could accidentally put AC grid power on the inverter output.

 

[Confusedcoconut]

Yes
You would turn the switch, and shut off the breaker feeding the inverter. Then, the inverter would be completely isolated from AC power.
The way you have it located, in the drawing. You could accidentally put AC grid power on the inverter output.

Ohh I see so like

 

[Confusedcoconut]

Yes
You would turn the switch, and shut off the breaker feeding the inverter. Then, the inverter would be completely isolated from AC power.
The way you have it located, in the drawing. You could accidentally put AC grid power on the inverter output.

Or actually the rotary changeover would then function as the ac isolator too? So I could move it to before the inverter to prevent any power from mains going into it?

Then instead of it feeding a separate 40a mcb on the consumer unit It could go before the rotary changeover on the growatts AC output?

 

[timselectric]

Two breakers in mains panel.
One breaker feeds inverter input. Then, inverter output feeds switch position #1.
The other breaker feeds switch position #2.
Switch output feeds loads panel.
(This is typical transfer switch wiring)

 

[Confusedcoconut]

Two breakers in mains panel.
One breaker feeds inverter input. Then, inverter output feeds switch position #1.
The other breaker feeds switch position #2.
Switch output feeds loads panel.
(This is typical transfer switch wiring)

So in theory if I had a small consumer unit after Meter I could also have a secondary small grid tied inverter feeding into the offgrid inverter to add extra solar capacity cheaply like so?

 

[timselectric]

Yes, that is an option.

 

[Confusedcoconut]

Yes, that is an option.

Thanks for the help with this

 

[Fliacik]

Hi guys what about Ground in EU ?? I have only L and N in my Grid and no Ground.
How can connect this inverter if my ground and neutral are same ?
Its better not connecting AC IN Ground and AC OUT Ground ? Or?

 

[SIdmouthsteve]

Hi.
With the growatt spf5000es being a offgrid inverter am I right in thinking I need to have a rotary changeover switch to completely prevent any backfeeding into grid and run all AC through the growatt like so?

Then in the unlikely event I should need intensive power consumption the 5kw unit cannot handle I can turn off the AC isolator to prevent backfeed and change the rotary isolators position to feed the consumer unit and not the inverter?

(I'll be getting an electrician to do all final wiring and check it off)

I would definitely put in the changeover switch. Suppose the inverter becomes faulty? The changeover switch lets you use the utility until the problem is fixed. The changeover should be between the output of the inverter and the mains (see diag below).

A solution to overloads is to put any really high power stuff on a utility only consumer unit (I have my EV 7.5kW charger on utility only and use the inverters to supply the 2.5kW charger).

"Backfeed" would only happen if the inverter powered consumer unit were simultaneously connected to the mains and the inverter.

 

[Vigo]

A solution to overloads is to put any really high power stuff on a utility only consumer unit (I have my EV 7.5kW charger on utility only and use the inverters to supply the 2.5kW charger).

I have been considering an EV or PHEV (have already owned 5 hybrids) to charge from my off-grid system, and one of the things i've thought about is whether, if i created a circuit to turn off the EV charger to avoid pulling down the whole house system (if my solar+batt could not support EV charging+house and would drain batteries to cutoff), whether i would have to go manually interact with the EV/charger to restart charging when that circuit was restored to power.

If that was the case and one had a grid connection (i dont), you might consider creating a circuit to cutoff the EV charging from the inverter when the system can't support it, and using an automatic transfer switch to transfer the charger to grid when that happens, and then back to inverter when conditions improve.

Bad idea? Do EV chargers already resume charging in the event of power loss when power is restored?

 

[SIdmouthsteve]

I have been considering an EV or PHEV (have already owned 5 hybrids) to charge from my off-grid system, and one of the things i've thought about is whether, if i created a circuit to turn off the EV charger to avoid pulling down the whole house system (if my solar+batt could not support EV charging+house and would drain batteries to cutoff), whether i would have to go manually interact with the EV/charger to restart charging when that circuit was restored to power.

If that was the case and one had a grid connection (i dont), you might consider creating a circuit to cutoff the EV charging from the inverter when the system can't support it, and using an automatic transfer switch to transfer the charger to grid when that happens, and then back to inverter when conditions improve.

You are off-grid so what you might need is 50kWh battery from an EV breaker.

 

[timselectric]

Hi guys what about Ground in EU ?? I have only L and N in my Grid and no Ground.
How can connect this inverter if my ground and neutral are same ?
Its better not connecting AC IN Ground and AC OUT Ground ? Or?

Ground terminals are already internally connected together. No jumper required.