Growatt SPF 3000TL LVM-ES 250v or 300v voc mppt?

[mtts]

I have those and got lost reading them as there were too many numbers there. There is no specific setting recommended!

It's there. That's where I got my settings from when I had the battery in USE2

 

[RCinFLA]

On most of the HF AIO inverters the PV input is not allowed to exceed the internal high voltage DC bus that feeds the sinewave PWM AC output bridge.

This is about 250vdc for 120vac inverters and 500vdc for 240vac inverters. Some AIO SCC controllers limit max PV input voltage to less than internal HV DC bus. The reason for the PV input voltage limit is the SCC controllers are DC-DC boost converters which must always stay below internal HV DC bus.

Some like the EG4 6548 AIO, and all 240/120vac split phase HF inverters, have an extra DC to DC converter between PV SCC output of 500vdc max and the internal 250 vdc bus.

With 250vdc max and typical panel Vmp of 0.81 to 0.85 Voc, the maximum realistic Vmp is about 200 vdc. If PV Voc initially exceeds 250vdc the SCC will not even startup to protect itself. The inverter spec may claim a greater Vmp but realistically they need to allow PV input to rise close to Voc to do a proper initial Vmp search.

The PV inputs are not isolated from AC polarity chopping for HV DC bus and the panels pos and neg lines are riding on top of 250v or 500v 60 Hz square wave, so you need double pole breaker on PV pos and neg lines to remove the AC chopping voltage from panels when breaker is off. The units with the extra DC to DC converter provide isolation between AC output and PV inputs, but the extra DC-DC converter adds a couple extra percent of loss to PV power conversion.

 

[MartyByrde]

Not necessarily. 250VDC is just a measurement.
250VOC is a measurement of voltage on an open circuit. (With no load connected)

I get confused because I’ve Growatts manual VDC but other inverters I’ve looked at use VOC. Are they comparable?

 

[timselectric]

Two different things.

 

[Jacks]

I purchased it from signature solar and the manual is available on there website. Here’s a screen shot from page 4 of features that states 300v voc.

Version 3.0 on Growatt's site can be downloaded here. On the Features page it has the correct 250V

SPF 3000TL LVM-ES - Off-Grid Storage Inverters - Growatt

SPF 3000TL LVM-ESoff grid inverters,solar inverter 3kw,solar off grid system

www.ginverter.com

And so does the older one on Watts247. I don't know why the one on Signature Solar is wrong.

 

[rloveless]

The best answer they could give you is "consult an electrician".
Put it this way, product manufacturer should specified how and what should be done, and the electrician would followed the instruction, he just make sure that something, for example, a GFCI outlet must be used when you plug your unit to one receptacle within 3' of a waterbody etc. The electrician doesn't detect how an electrical device should be installed, the manufacturer does!

But in this case the instructions contradict themselves. From my understanding, Voc is alway the measurement of the solar panels without a load.

 

[rloveless]

I purchased a Growatt SPF 3000TL LVM-ES and am trying to figure out what the solar mppt max voc is. In the manual on page 4 it says the mppt range is 150v - 250v and a voc of 300v. But on page 12 it says max PV array open circuit voltage is 250v. If the unit can handle it I would like to set my strings up to have 258.3v voc and an optimal operating voltage (vmp) of 208.6v. However, I don’t want to mess up my inverter. I’m fairly new to this stuff and might be interpreting something wrong in the manual.
If any can give me some insight it would be greatly appreciated.

I had the same question, Did you 258.3v connected cause any issues? The more confusing this is that it states you can have an operating voltage up to 250volts... and that would mean that your voc would obviously be above that(around 300voc). From my understanding, Voc is always the measurement of the solar panels without a load... with or without being connected to your growatt.

 

[SYKSolar]

I had the same question, Did you 258.3v connected cause any issues? The more confusing this is that it states you can have an operating voltage up to 250volts... and that would mean that your voc would obviously be above that(around 300voc). From my understanding, Voc is always the measurement of the solar panels without a load... with or without being connected to your growatt.

NO. 250V. Used the number shown on the Unit on the right side . Always used that. Manual usually applies to several models.

 

[rloveless]

I purchased a Growatt SPF 3000TL LVM-ES and am trying to figure out what the solar mppt max voc is. In the manual on page 4 it says the mppt range is 150v - 250v and a voc of 300v. But on page 12 it says max PV array open circuit voltage is 250v. If the unit can handle it I would like to set my strings up to have 258.3v voc and an optimal operating voltage (vmp) of 208.6v. However, I don’t want to mess up my inverter. I’m fairly new to this stuff and might be interpreting something wrong in the manual.
If any can give me some insight it would be greatly appreciated.

NO. 250V. Used the number shown on the Unit on the right side . Always used that. Manual usually applies to several models.

Doesn't it say mppt Max working voltage is 250 V? .... wouldn't that mean that the open circuit voltage is more than 250v?

 

[SYKSolar]

Doesn't it say mppt Max working voltage is 250 V? .... wouldn't that mean that the open circuit voltage is more than 250v?

 

[rloveless]

View attachment 137485

Yeah the MPP voltage range is 120 to 250. That is odd because you can never get up to the working voltage of 250 volts DC without having a higher than 250 voltage open circuit...Odd I don't understand it.