Ian's YT on inverters with autotransformers

[EastTexCowboy]

Interesting video on why Ian (watts247) no longer carries inverters with an autotransformer. Would love to hear your opinions.

 

[Quattrohead]

My opinion is he made the video after he got rid of all of his stock.

 

[Danke]

Ya, I saw this one a while back.

 

[efficientPV]

This same thing happens in factories with 3 phase motors. Every motor is trying to balance the grid besides doing the work it has to do. A 10% imbalance can damage the motors from overheating. Many motor controls include imbalance detection and will shut down the motor. On the other hand, transformers can double the supplied current you need on one phase. If you don't like the grid, stay off it.

 

[timselectric]

Would love to hear your opinions.

Same as Ian's.

 

[Zwy]

Interesting video on why Ian (watts247) no longer carries inverters with an autotransformer. Would love to hear your opinions.

I think GW told him it was a low frequency inverter and even the listing currently (which shows he is no longer selling these models) states it is a low frequency inverter. Most likely there were cases where there had been fires due to overloaded circuits or breakers would trip intermittently and so he started to check into why this was occurring. The result is he determined the units were HF with an autotransformer.

Seeing the amps double on the operating leg while the other leg was open is just dangerous. Not only is the wire overloaded but the panel is also passing double amps thru one leg. Of course, the breakers should have tripped in such cases if the load was large enough. It's those cases where things get pushed right up to limit that make it dangerous.

 

[RCinFLA]

Victron, Outback, and Xantrex LF inverters monitor for AC input imbalance neutral current in output transformer. They will release from grid if AC input imbalance gets too great, causing more than a few amps of grid balancing current on transformer. This allows them to have an input neutral connection.

The Chinese LF inverters do not monitor the neutral current for AC input L1-N-L2 imbalance and should not have AC input neutral connected. This means all 120 vac output loads are carried by inverter output transformer when 240vac only AC input is supplied.

The Chinese LF inverters should not be connected to grid.

They will never achieve grid interconnect compliance (or more important, safety) without input neutral connection as it creates a ground-neutral issue on output subpanel that feeds house. If subpanel is grounded, which it must be, with 240vac L1-L2 only AC input connections, then by default the AC output neutral of inverter is also grounded in common with grid and grid's neutral is connected to AC output neutral of inverter via the required neutral-ground bonding in main grid input breaker panel. So the Chinese inverter is still getting AC input neutral connected to AC output neutral. Any AC input neutral imbalance current is still flowing to inverter output transformer via common ground on AC input and AC output grounding paths. AC input neutral-ground bond plus AC output neutral-ground bond equals AC input neutral connected to AC output neutral (via the common ground connections).

Too much AC input L1-N-L2 imbalance can damage inverter.

 

[G00SE]

I’ve been thinking about the GW 8k instead of the 12k because of 6AWG wires. I’m off grid so I don’t need to be concerned with the neutral and grid but it looks like the 12k would exceed wire ratings whereas the 8k wouldn’t.
I’m trying to find the video again that explained the why behind this as I don’t quite recall the significance but I’m fairly certain it was the 6AWG being the issue
I do wonder if the sun power 18k has More space for larger as the 8k really isn’t large enoughb

 

[Quattrohead]

You can use the 12k with 6awg AS LONG AS you protect the wire with the appropriate size breaker.
So a quick surge of 12kw will not likely trip the breaker and the copper wire will handle it easy.
It would take quite the load for a good while to start the PVC melting.
Just my opinion, follow at your own risk ?

 

[Farm Boy]

This is an interesting video for some one like me who has been using one. I bought mine 2 1/2 yrs ago from watts 24/7. They were (advertised) as a
L.F. inverter, guess that was a lie. Been working Great all this time and at least it will charge the batteries or could be used as a UPS and (NEVER FEED THE GRID). I love my 18KPV for the aspects of safety, proper wire size connections, noise, and many other feature (advertised) that I learn after wards can't be used with out taking the (chance of FEEDING THE GRID). If they get that part figured out for us (OFF GRID USERS), it will be a superb unit for off grid use. Had been wondering why he stopped supporting them, now I understand why.

 

[SignatureSolarJames]

Growatt is a nightmare to warranty, they are always late in parts.

 

[B-Mod]

Growatt is a nightmare to warranty, they are always late in parts.

Not cool to find out after I purchased 9 of them from your company......

 

[SniperX]

Growatt is a nightmare to warranty, they are always late in parts.

 

[SignatureSolarJames]

Not cool to find out after I purchased 9 of them from your company......

we’ve warrantied a lot out of pocket in an effort to be cool in spite of manufacturer abandonment

 

[LydMekk]

Growatt tend to evade all warranty support and parts in the EU.
I am evaluating lawyers or bank return as we speak. Have been at it for 6 months now.
NEVER trust Growatts warranty claims.