Illustration

MicroinverterEnphase Energy

Enphase Energy IQ9S-3P-277-B-DOM-US

Name: Enphase Energy IQ9S-3P-277-B-DOM-US
Brand: Enphase Energy

Microinverter. 2 models, 427 W–548 W AC at 277 V.

UL 1741 SBCEC listed · Dec 22, 2025Rapid shutdown

Model

Rated AC power548 W
CEC weighted efficiency97.5%

Models & power ratings

CEC Grid Support Inverter List (Oct 7, 2026) · NLR SAM inverter library · 2 models

Model	Nominal AC	Grid voltage	CEC continuous	Rated AC (SAM)	CEC weighted eff.	DC test window	CEC listed	UL 1741 SB
IQ9N-3P-277-A-DOM-US +1 SKU	427 W	277 V	427 W	427 W	97.5%	28–45 V	Dec 22, 2025	SB
IQ9S-3P-277-B-DOM-US +1 SKU	548 W	277 V	548 W	548 W	97.5%	32–55 V	Jun 22, 2026	SB

DC input (PV side)

CEC Grid Support Inverter List (Oct 7, 2026) · NLR SAM inverter library

CEC test DC voltages (min / nom / max)32 / 44 / 55 V
DC input at rated output (CEC test)562 W

AC output (grid side)

CEC Grid Support Inverter List (Oct 7, 2026)

Rated AC power548 W
CEC-measured continuous output548 W
Grid voltage277 V
Phase3-phase 277 V

Efficiency

CEC Grid Support Inverter List (Oct 7, 2026) · NLR SAM inverter library

CEC weighted efficiency97.5%
Night-time standby (tare)0.22 W
Power to start converting3.2 W

CEC weighted efficiency is measured by an accredited lab at six power levels and three DC voltages — the number to compare between inverters.

Grid & smart-inverter certification

CEC Grid Support Inverter List (Oct 7, 2026) · Enphase Energy datasheet

UL 1741 SB (3rd ed.)Yes — Intertek, certificate May 15, 2026
UL 1741 SA (SA8–SA13)Yes — Intertek
Volt-VAr with reactive power priority (SA13)Yes
Freq-Watt / Volt-Watt (SA14–15)Yes
Disable permit service / limit active power (SA17–18)Yes
CSIP (IEEE 2030.5) conformanceVia gateway during testing (Y*)
Anti-islanding method groupsGroups 1 (manufacturer-reported)
Power control system (PCS)Stated in CEC listing (power control system)
CEC listedDec 22, 2025
Last CEC updateMar 2, 2026
Standards listed on the datasheetUL 1741 SA, UL 1741, IEEE 1547, UL 62109, FCC Part 15, CA Rule 21, NEC 690.12 (rapid shutdown)

UL 1741 SB is required for new interconnections in California (Rule 21) since 2026.

Safety & protection

Enphase Energy datasheet

Rapid shutdown (NEC 690.12)Yes (NEC 690.12, datasheet)

Monitoring & communication

Enphase Energy datasheet

InterfacesPLC, CAN

Size, weight & environment

Enphase Energy datasheet

Weight2.6 lb (1.2 kg)
Enclosure ratingClass II double-insulated
CoolingNatural convection (no fans)
Operating temperature−40 to +65 °C
Made inmade in the USA

Panel compatibility & string sizing

NLR SAM inverter library · NLR PVWatts v8 · CEC PV Module List · Cali-Graf calculation

CityColdest air, °CHottest cell, °C

IQ9S-3P-277-B-DOM-US: max DC 55 V · MPPT 32–55 V (CEC test window)

Most-permitted panels in Southern California

Panel	Power	Voc cold / Vmp hot	Check	DC/AC	Installed together
Qcells Q.PEAK DUO BLK ML-G10.C+ 410	410 W	48.1 / 30.6 V	⚠ Below MPPT at peak heat	0.75	—
Qcells Q.PEAK DUO BLK ML-G10+ 410	410 W	48.1 / 30.6 V	⚠ Below MPPT at peak heat	0.75	—
LONGi LR5-54HABB-400M	400 W	39.3 / 25.3 V	⚠ Below MPPT at peak heat	0.73	—
JA Solar JAM54S31-405/MR	405 W	39.4 / 25.5 V	⚠ Below MPPT at peak heat	0.74	—
Hyundai Solutions HiN-T440NF(BK)	440 W	40.9 / 27 V	⚠ Below MPPT at peak heat	0.8	—
Silfab Solar SIL-440QD	440 W	41.1 / 28 V	⚠ Below MPPT at peak heat	0.8	—
Qcells Q.TRON BLK M-G2+ 430	430 W	41.3 / 28 V	⚠ Below MPPT at peak heat	0.78	—
Qcells Q.TRON BLK M-G2.H+ 430	430 W	41.3 / 28 V	⚠ Below MPPT at peak heat	0.78	—
REC Group REC460AA Pure-RX	460 W	68.8 / 47.1 V	✗ Cold Voc above max input	0.84	—
Elin (Sirius PV) ELNSM54M-HC-410	410 W	39.3 / 25.3 V	⚠ Below MPPT at peak heat	0.75	—
Qcells Q.TRON BLK M-G2.C+ 430	430 W	41.3 / 28 V	⚠ Below MPPT at peak heat	0.78	—
Tesla TSP-420	420 W	43.4 / 27.7 V	⚠ Below MPPT at peak heat	0.77	—

Voltage check only, from CEC panel data and NLR weather for the city. Final design must follow the inverter manual and NEC 690.7.

About Enphase Energy

CEC Grid Support Inverter List (Oct 7, 2026)

ManufacturerEnphase Energy
Listed in CEC asEnphase Energy, Inc.
Websiteenphase.com
Models on CEC lists223

Other series

IQ8 Series · 1104 permitsIQ7 Series · 471 permitsIQ8-3P Series · 1 permitsIQ9 Series

Documents

manufacturer documents

PDF
IQ9N Commercial Microinverter data sheet
Datasheet · Enphase
PDF
IQ Gateway Commercial Pro data sheet
Datasheet · Enphase

Questions & answers

How efficient is the Enphase Energy IQ9-3P Series?

The California Energy Commission lists a weighted efficiency of 97.5% for Enphase Energy IQ9-3P Series models, measured at six power levels and three DC voltages.

What sizes does the Enphase Energy IQ9-3P Series come in?

The CEC list includes 2 models from 427 W to 548 W AC: IQ9N-3P-277-A-DOM-US, IQ9S-3P-277-B-DOM-US.

Is the Enphase Energy IQ9-3P Series certified to UL 1741 SB?

Yes — the CEC Grid Support Inverter List shows UL 1741 SB for all models.

What is the IQ9S-3P-277-B-DOM-US’s DC input voltage range?

CEC tested it at 32–55 V DC.

Sources

California Energy Commission — Grid Support Inverter List (solar and battery inverters), data as of Oct 7, 2026. Manufacturer-reported, confirmed by CEC against certificates and test reports.
Enphase Energy — datasheet IQ9N Commercial Microinverter data sheet.
Enphase Energy — document library on the manufacturer’s website (links above).
NLR (formerly NREL) — System Advisor Model CEC inverter library (version 2026.7.3).
NLR (formerly NREL) — PVWatts v8, NSRDB PSM v3 typical-year weather for Los Angeles, Palmdale, Riverside, Santa Clarita, Chula Vista, Huntington Beach.
California Energy Commission — PV Module List (module electrical data for the compatibility check).
Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).