Growatt 12000t dvm-mpv: neutral bond?

[TexasSun]

I'm helping a friend with his setup. He got this inverter from Growatt, which only has 240v-ac output, no neutral wire.

He wants to get both 240v-ac and two 120v-ac legs from it. My question is if this unit has a bond between one of the hot legs and ground? Growatt units made for the US do not have this, but European models do.

It's the difference whether we need an isolation transformer or a regular split-phase transformer. The split-phase transformer only needs to generate the center tap neutral wire. But an isolation transformer will take the two hot legs, and generate two new hot legs as well as the neutral, so it is larger and more expensive.
Thanks

 

[BentleyJ]

With the unit turned off completely its easy enough to test for a permanent bond. Just check continuity between ground and each of the Hot legs. Although this will not tell you if the inverter has dynamic bonding via an internal relay.
For this, the inverter would have to be on. In this case one of the Hot wires would show 0 volts to ground and the other would show voltage to ground. You would have to be comfortable working with live 240V.

It sounds like the inverter may be a European model, is it 50 or 60Hz?

 

[TexasSun]

With the unit turned off completely its easy enough to test for a permanent bond. Just check continuity between ground and each of the Hot legs. Although this will not tell you if the inverter has dynamic bonding via an internal relay.
For this, the inverter would have to be on. In this case one of the Hot wires would show 0 volts to ground and the other would show voltage to ground. You would have to be comfortable working with live 240V.

It sounds like the inverter may be a European model, is it 50 or 60Hz

Good idea. I've not had my hands on it yet, but will check impedance when I do. I don't know about EU model, but from what I'm reading, this is the version sold in Europe.

 

[timselectric]

Are you sure that's the correct model number?
That model should be a split-phase output.

 

[TexasSun]

Are you sure that's the correct model number?
That model should be a split-phase output.

That is a good question! That is the model my friend told me. I specifically asked if the model # has a -US in it, and he said no.

BUT... here is the manual: https://us.growatt.com/upload/file/SPF_4000-12000_DVM-MPV_User_Manual_EN_202212.pdf
Looking at it, page 2, it shows both 120 and 240v loads. And without a transformer! But page 8 shows hooking up for either 240 or for 120v, not all the terminals (2 hots & neutral).

I'm so used to growatt units being only 240v, I just assumed it was 240-only. I'll ask my buddy to send me a picture of the model #. And call signautre solar where he bought it.

 

[timselectric]

That is a good question! That is the model my friend told me. I specifically asked if the model # has a -US in it, and he said no.

BUT... here is the manual: https://us.growatt.com/upload/file/SPF_4000-12000_DVM-MPV_User_Manual_EN_202212.pdf
Looking at it, page 2, it shows both 120 and 240v loads. And without a transformer! But page 8 shows hooking up for either 240 or for 120v, not all the terminals (2 hots & neutral).

I'm so used to growatt units being only 240v, I just assumed it was 240-only. I'll ask my buddy to send me a picture of the model #. And call signautre solar where he bought it.

If it was purchased from Signature Solar. Then I'm sure that it's a split-phase unit.
PS: that unit has a built-in transformer.

 

[SniperX]

If it was purchased from Signature Solar. Then I'm sure that it's a split-phase unit.
PS: that unit has a built-in transformer.

That is why it is so damn heavy!