Out of stock

Fronius Primo 3.8kW Inverter 3.8-1

price as of May 27
Solar Loan from 6.99%
All Fronius USA LLC products


Input Voltage DC410
Output Voltage AC208 / 240 V
Solar panel compatibility60/72 - 120/144 cell
TypeGrid-Tie Inverters
Rated Efficiency96.7%
Dimensions LxWxH16.9 x 24.7 x 8.1 in
Weight47.29 lb
ManufacturerFronius USA LLC
Manufacturer Part #Primo3.8-1
Operating Temperatures -40 to 131°F
Warranty10 Years Manufacturer
Delivery Time 5-7 business days

About product

Fronius Primo is a great inverter for residential solar systems. It’s lightweight, easy to install, shows great efficiency and maximizes the production of your system by utilizing dual MPPT trackers. 

This model shows 3.8 kW of rated power output with maximum efficiency of 96.7%. The maximum output current is 15.8 A at 240 V, 18.3 A at 208 V. Operating voltage ranges from 80 V to 600 V.

The Fronius Primo inverter is suitable both for outdoor and indoor installation. It comes with a 10 year warranty that can be extended to 15 and 20 years. It supports wireless connection and Ethernet. Datalogging and/or updating can be done via USB.


  • Power output: 3.8 kW
  • Output current: 15.8 A at 240 V, 18.3 A at 208 V
  • 2 MPPTs
  • Maximum efficiency: 96.7>#/p###
  • Warranty: 10 years, extendable to 15 and 20 years
  • Dimensions: 16.9 x 24.7 x 8.1 in
  • Weight: 47.29 lb

Reviews & Questions

  • Reviews (3)
  • Questions (3)
The inverter itself is great, but it’s suitable only for very small installations. Well, a 5kW one actually is fine. Too bad it’s grid -tie, i wanted to use it for my van(
10/01/2021 05:07 pm
man, i love the production. feels like 2 mppts do make a difference. really nothing to complain about here, great inverter, very happy with it.
09/17/2021 10:25 am
Nice and small. Love the design. The service was good too!
09/14/2021 02:02 am

Leave a review

Can you send it to Montreal?
10/03/2021, 16:00
Not at the moment. We might extend delivery to Canada in the future.
does it keep working when grid goes down?
09/12/2021, 08:35
No. All grid-tie inverters are required to shut down during power outages for safety reasons.
what is MPPT?
08/08/2021, 12:04
Maximum Power Point Tracker. Basically, it serves to balance voltage and current in the system for maximum production.