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Model SE66.6K-USRP0BNU4 | 66,600 VA Rated Output | 277/480V 3-Phase WYE | 98.5% CEC Efficiency | 90kW DC Input | RS485 + Ethernet | NEC 690.11 & 690.12 Compliant
The SolarEdge SE66.6K-USRP0BNU4 is a 66,600 VA three-phase commercial string inverter built on SolarEdge's Synergy modular inverter architecture, engineered for North American 277/480V four-wire WYE commercial and industrial grid connections where high-output single-unit density, module-level power optimization, and NEC-compliant integrated safety are required. Delivering a CEC weighted efficiency of 98.5% from a maximum DC input of 90,000W per unit at STC, the SE66.6K operates across an AC output voltage range of 244–305 Vac (L-N) and 422.5–529 Vac (L-L) at 59.3–60.5 Hz, supplying up to 80A continuous output current per phase at 277V across all three phases. Synergy technology divides the inverter into independently operating units that can be installed, serviced, or replaced one at a time by a two-person crew without taking the full system offline, while built-in RS485 and Ethernet communications with optional cellular GSM deliver module-level monitoring and remote management through the SolarEdge monitoring platform. Integrated rapid shutdown and arc fault protection comply with NEC 690.11 and 690.12, and a built-in DC safety switch with optional surge protection complete the safety stack for commercial PV applications.
Synergy Technology — 98.5% CEC Weighted Efficiency at 66.6 kW: SolarEdge's Synergy architecture divides the SE66.6K into independent functional units that together deliver 66,600 VA of rated and maximum AC output at a CEC weighted efficiency of 98.5% — one of the highest published efficiency ratings available for commercial three-phase string inverters in this power class — accepting up to 90,000W of DC input at STC and converting it to clean 277/480V three-phase AC output with minimal conversion losses, directly maximizing the energy yield and financial return of the PV system over its operating lifetime compared to lower-efficiency inverter alternatives in the same output range.
Power Optimizer Integration — Module-Level MPPT & Harvest Maximization: The SE66.6K is designed as the central inverter in a SolarEdge power optimizer system — working in conjunction with SolarEdge DC power optimizers mounted at each solar module to independently track and maximize the power point of every individual panel in the array regardless of shading, soiling, orientation mismatch, or manufacturing variation, eliminating the string-level mismatch losses that reduce energy harvest in conventional three-phase string inverter deployments on complex commercial rooftops, multi-orientation facades, and carport structures where partial shading is unavoidable and uniform string irradiance cannot be guaranteed across the full operating day.
Module-Level Monitoring — Ethernet, RS485 & Optional Cellular GSM: Built-in RS485 and Ethernet communication interfaces connect the SE66.6K directly to the SolarEdge monitoring platform — streaming real-time module-level power, voltage, and energy data from every optimizer in the connected array to the SolarEdge cloud monitoring portal and installer app — while an optional cellular GSM communication module enables full monitoring and remote management capability at sites without available wired network infrastructure, providing system owners, O&M teams, and EPCs with the complete performance visibility needed to detect underperforming modules, validate system health, and document energy production for billing, incentive, and warranty purposes.
Modular Design — Two-Person Installation, Independent Unit Serviceability: Synergy's modular architecture splits the SE66.6K into independently operable units that mount on walls or standard inverter rails — allowing a standard two-person installation crew to handle each unit individually without specialized lifting equipment — and enabling field service teams to remove, replace, or upgrade a single unit while the remaining units continue operating and producing power, eliminating the full-system downtime that conventional monolithic commercial inverter service requires and significantly reducing O&M labor costs and energy production losses over the system's operational lifespan on commercial rooftop, ground-mount, and carport installations.
NEC 690.11 & 690.12 Compliant — Rapid Shutdown & Arc Fault Protection: The SE66.6K integrates rapid shutdown functionality compliant with NEC Article 690.12 — automatically reducing DC conductor voltage within the array boundary to safe levels upon loss of AC grid power or manual activation, enabling first responders to work safely on and around commercial rooftops where the inverter is installed — and arc fault circuit protection compliant with NEC Article 690.11 that continuously monitors DC circuits for arc fault signatures and disconnects the affected circuit before arc-initiated fires can develop, backed by a built-in DC safety switch and optional DC surge protection device for comprehensive protection of the full DC system from grid to module level.
The SE66.6K-USRP0BNU4 operates on the North American 277/480V three-phase WYE grid via a four-wire plus protective earth (L1-L2-L3-N-PE) AC connection, delivering balanced three-phase output at up to 80A continuous per phase at 277V across the 59.3–60.5 Hz operating frequency range. The Synergy inverter architecture processes the DC power delivered by the connected SolarEdge power optimizer string — each optimizer having independently tracked and maximized its paired module's power point output — converting the optimized DC bus to three-phase AC output at 98.5% CEC weighted efficiency and feeding it to the commercial grid connection point. Ground fault isolation detection at 350 kΩ sensitivity per unit continuously monitors the DC system for ground faults and triggers automatic disconnection to protect both personnel and equipment, while the RS485 and Ethernet interfaces relay real-time performance telemetry to the monitoring platform throughout system operation.
Independent Unit Operation & High System Uptime: Each Synergy unit within the SE66.6K operates independently with its own DC input, power conversion stage, and AC output contribution — meaning a fault, service event, or planned replacement affecting one unit does not interrupt the operation of the remaining units, which continue converting and delivering power to the grid at their individual rated capacity throughout the service event, maintaining system-level energy production and minimizing the financial impact of individual unit maintenance requirements compared to conventional single-unit commercial inverters of equivalent total output.
Integrated DC Safety Switch & Optional Surge Protection: A built-in DC safety switch provides a lockable, code-compliant DC disconnect point at the inverter for installation and maintenance isolation without requiring a separate external DC disconnect enclosure — simplifying the balance-of-system design and reducing equipment and labor costs on commercial installations — while the optional DC surge protection device (SPD) protects the inverter's internal power electronics from transient overvoltage events caused by nearby lightning strikes and switching surges that would otherwise reach the inverter through the DC string wiring from the rooftop array.
Versatile Inverter Communication & Remote Management: The combination of RS485, Ethernet, and optional cellular GSM communication options gives installers and system operators the flexibility to integrate the SE66.6K into virtually any commercial site's network architecture — using wired Ethernet for sites with available IT infrastructure, RS485 for daisy-chained multi-inverter communication in larger commercial arrays, or cellular GSM for remote and rural installations where neither Ethernet nor RS485 network infrastructure is available — with all three pathways delivering the same full module-level monitoring and remote management capability through the SolarEdge monitoring platform and API.
| Manufacturer | SolarEdge Technologies |
| Model Number | SE66.6K-USRP0BNU4 |
| Rated AC Power Output | 66,600 VA |
| Maximum AC Power Output | 66,600 VA |
| AC Output Line Connections | 4-Wire WYE (L1-L2-L3-N) + PE — Three-Phase |
| AC Output Voltage (L-N) | 244 – 277 – 305 Vac |
| AC Output Voltage (L-L) | 422.5 – 480 – 529 Vac |
| AC Frequency Range | 59.3 – 60 – 60.5 Hz |
| Maximum Continuous Output Current | 80 A per Phase @ 277V |
| Maximum DC Power Input (STC) | 90,000 W per Unit |
| CEC Weighted Efficiency | 98.5% |
| Ground Fault Isolation Detection | 350 kΩ Sensitivity per Unit |
| Communication Interfaces | RS485 + Ethernet — Optional Cellular GSM |
| Monitoring | Module-Level Real-Time — SolarEdge Monitoring Platform & API |
| Safety — NEC Compliance | Rapid Shutdown (NEC 690.12) + Arc Fault Protection (NEC 690.11) |
| DC Disconnect | Built-In DC Safety Switch + Optional DC Surge Protection Device (SPD) |
| Architecture | Synergy Modular — Independent Units, Wall or Rail Mount, Two-Person Install |
| Grid Compatibility | North America 277/480V Three-Phase — UL 1741 / IEEE 1547 |
NEC Safety Compliance: Rapid Shutdown — NEC Article 690.12 | Arc Fault Circuit Protection — NEC Article 690.11
Grid Standard: North America 277/480V Three-Phase WYE — UL 1741 / IEEE 1547 Grid Interconnection
Communication: RS485 + Ethernet Standard | Optional Cellular GSM for Remote Sites
Monitoring: SolarEdge Module-Level Monitoring Platform — Real-Time & Historical, API Access
Optimizer Compatibility: SolarEdge Power Optimizers — Full Module-Level MPPT & Safety Shutdown
Ground Fault Detection: 350 kΩ Sensitivity per Synergy Unit — Continuous DC System Monitoring
● Available | Contact us for lead time and pricing
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