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Fortress Power Envy Duo 21 Whole-Home Hybrid Solar Inverter

Fortress Power Envy Duo 21 Whole-Home Hybrid Solar Inverter

SKU: FP-850079800021

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Description

Fortress Power Envy Duo 21 Whole-Home Hybrid Solar Inverter

Product Description

The Fortress Power Envy Duo 21 is a 48V hybrid solar inverter designed for demanding residential and light-commercial energy systems. It supports 240V split-phase and 208V three-phase configurations while delivering 12kW of continuous backup output across both configurations.

The inverter accommodates photovoltaic arrays up to 25kW, with a maximum usable PV power of 21kW. Integrated AC and DC breakers, a built-in rapid-shutdown transmitter and remote monitoring help simplify installation and ongoing system management.

  • 12kW continuous backup output at 240V or 208V
  • Maximum grid output of 16kW at 240V
  • Maximum grid output of 13.8kW at 208V
  • Supports photovoltaic arrays up to 25kW
  • 21kW maximum usable photovoltaic power
  • Three MPPTs with a 2:2:1 input configuration
  • Supports 240V split-phase systems
  • Supports 208V three-phase systems
  • Compatible with Fortress Power 48V batteries
  • Supports operation without a battery
  • Integrated AC and DC breakers
  • Built-in rapid-shutdown transmitter
  • Supports up to 10 inverters in parallel
  • Maximum combined output of 120kW
  • Remote system monitoring through the Fortress Power mobile app
  • Remote firmware updates
  • NEMA 4X and IP66 protection
  • Touch color screen

Specifications

Specification Details
Manufacturer Fortress Power
Model Envy Duo 21
GTIN 00850079800021
Maximum PV Array Power 25,000W
Maximum Usable PV Power 21,000W
Number of MPPTs Three
Inputs per MPPT 2:2:1
Maximum Usable Input Current 26A / 26A / 15A
Maximum Short-Circuit Input Current 31A / 31A / 19A
PV Startup Voltage 100V
Nominal MPPT DC Voltage 360V
DC Voltage Range 100–550V
MPPT Operating Voltage Range 120–440V
Backup Output Current 50A at 240V / 57.7A at 208V
Backup Output Voltage 120/240V and 120/208V
Continuous Backup Output 12,000VA at 240V / 12,000VA at 208V
Backup Operating Frequency 60Hz
Peak Backup Power Twice rated power for 0.5 seconds
Backup THDv Less than 3%
Switching Time Less than 20 milliseconds
Maximum Grid Output Current with PV 66.7A
Maximum Grid Output with PV 16,000W at 240V / 13,800W at 208V
Continuous Battery-Only Output 12,000W at 240V / 12,000W at 208V
Rated Grid Voltage 120/240V and 120/208V
Grid Operating Voltage Range 180–270V
Grid Operating Frequency 50/60Hz
Grid Frequency Range 55–65Hz
Power Factor 0.99 at full load
Reactive Power Adjustment Range -0.8 to +0.8 leading, adjustable
Grid THDi Less than 3%
Synchronous Inrush Current 35A
Compatible Battery Type Lithium battery or no battery
Nominal Battery Voltage 48V
Battery Voltage Range 40–60V
Maximum Battery Charge Current 250A
Maximum Battery Discharge Current 250A
Maximum PV-to-Grid Efficiency 97.50%
Maximum Battery-to-Grid Efficiency 94%
CEC Efficiency 96.90%
Maximum Parallel Units 10
Maximum Combined Output 120kW
Dimensions 22.3 × 35.2 × 11.2 inches
Metric Dimensions 566 × 893 × 285 mm
Weight 125.71 lbs / 57 kg
Protection Rating NEMA 4X / IP66
Cooling Smart cooling fans
Topology High-frequency transformerless
Relative Humidity 0–100%
Maximum Operating Altitude Less than 6,561 feet / 2,000 meters
Operating Temperature -13°F to 140°F / -25°C to 60°C
Temperature Derating Above 104°F / 40°C
Noise Level Less than 67dB
Average Idle Consumption 60W
Display Touch color screen
Communication RS485, Wi-Fi and CAN
Estimated Delivery One to two weeks

FAQs

Q: How much continuous backup power does the Envy Duo 21 provide?
A: It provides 12,000W of continuous backup output at either 240V or 208V.

Q: What is the maximum supported solar-array size?
A: It supports a photovoltaic array up to 25,000W, with maximum usable PV power of 21,000W.

Q: Does the Envy Duo 21 support three-phase power?
A: Yes. It supports 120/208V three-phase applications as well as 120/240V split-phase systems.

Q: Can multiple Envy Duo 21 inverters operate together?
A: Yes. Up to 10 units can operate in parallel for a combined output of 120kW.

Q: Is a battery required?
A: No. The listed battery configurations are lithium battery or no battery.

Whole Home Solar hybrid inverter; Max 16KW ongrid and 12KW off-grid continous output;Max 25KW PV array; 200A transfer switch: IP 65 outdoor rated; pre-built AC &DC breakers; Built-in Apsmart RSD transmitter; 120/240V Single and split phase, 120/208V three phase, 127/220V single & split phase; 50/60HZ; breakers included


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