230v or 120v inverter selection

[AirJer]

Grid Tie Inverter recommendations please:

I am trying to at the least significantly support or completely cover operation of my domestic submersible water pump and Central HVAC during daylight hours. I will not utilize any batteries at this time but someday hope to upgrade for them.

I have 20 PV panels of 23 volt and 175 watts each.

230v or 120v inverters?
Better to use more inverters of lower wattage or
Less inverters with higher wattage capability?

The pump is 3HP, 230v-17 max amps and 30 amp breaker
The HVAC is 230v with 37 Amp Min. draw and 60amp breaker.

I apologize if I missed this area of info during my recon through the posts on this site.

Please respond and freely think out loud on this topic!

THANKS

AJ
"I fix stupid, one middle finger at a time"

[SunEagle]

Hello AJ and welcome to Solar Panel Talk.

I am a little confused. I believe you plan to use 3500 watts of panels connected to an "inverter" to run both your 3hp 230v pump and your HVAC system rated 230v @ 37amp (~8500 watts).

So first off your inverter needs to be able to generate 230volts, but with only 3500 watts you won't be able to run either your 3Hp pump or 8500watt HVAC. You don't have enough panel wattage or the ability to run an AC load of that size without a battery system and if you did have a battery inverter it would need to be rated over 10,000watts.

You could use those panels to help offset some of your electrical loads but you will need the Electric Grid to run the pump and HVAC system.

So what is your plan? Will you have a legal grid tie system or large and expensive off grid system?

[AirJer]

Understood I don't have the wattage to drive the big stuff. You answered my question. This will be a legal grid tie supplement system only to lower my overall utility co usage.

Thanks for the feedback!

[SunEagle]

Understood I don't have the wattage to drive the big stuff. You answered my question. This will be a legal grid tie supplement system only to lower my overall utility co usage.

Thanks for the feedback!

If your plan is a grid tie system then depending on the area of your roof and which way it is facing, would determine the number and size of your inverter. Most of the good ones can accept two different strings of panels and with only 3500 watts I would think a single inverter rated 4000 to 5000 watts using a 240volt connection to your main power panel would work.

[inetdog]

For a grid tie system the POCO will probably insist on a 240V GTI to balance the power supplied between the L1 and L2 service conductors.
120V is a more common option for off-gridders who do not have large motors that require 240.