Class A pyranometer 3S-2IS

Modbus RTURS-485digital

Product overview
The SEVEN 3S-2IS Dual Orientation Irradiance Sensor is designed to compute accurate Performance Ratio (PR) values for dual-orientation PV plants by measuring irradiance on two planes and calculating a weighted average based on panel counts per orientation. The device allows the user to configure the number of panels in each orientation to reflect site layout variations. The 3S-2IS supports simultaneous connection of two irradiance reference cells, two module temperature sensors, one ambient temperature sensor and one wind speed sensor.

How it works
Each monocrystalline silicon reference cell measures irradiance on its plane. The onboard microcontroller accepts the number of panels per orientation via the configuration interface and computes a weighted Total Effective Irradiance where orientations with more panels have greater influence. PT1000 temperature sensors on each reference cell provide continuous temperature compensation to maintain Class A accuracy. Total Effective Irradiance and total effective module temperature are output via Modbus RTU (or SunSpec where applicable) for integration with dataloggers and monitoring platforms.

Key features

• Dual-plane measurement: simultaneous irradiance measurement on two surfaces and calculation of effective irradiance.
• Plug-and-play Modbus integration: RS485, Modbus RTU compatible with common dataloggers, inverters and monitoring systems.
• IEC Class A precision: compliant with IEC 61724-1 and IEC 60904 calibration procedures.
• Expandable inputs: supports 2 module temperature sensors, 1 ambient temperature sensor and 1 wind speed sensor via the same RS-485 connection.
• Field-ready housing: aluminum weatherproof enclosure with IP54 rating (IP65 and IP68 options available).
• Low power consumption and durable cable: supplied with 3 m LIYYC11Y PUR UV- and weather-resistant cable (6 twisted wires including ground).
• Calibration: each sensor calibrated under Class AAA Sun Simulator per IEC 60904-2 and IEC 60904-4 using an ISFH-Germany calibrated reference cell; also tested under natural sunlight against a Fraunhofer ISE reference cell.
• Five-year warranty.

Additional notes
The device accepts panel counts per orientation via its configuration interface. Final Total Effective Irradiance and temperature values can be transmitted over Modbus RTU (and SunSpec where supported) for direct integration with dataloggers, SCADA or performance monitoring systems.

Delivery times

• Small orders: approx. 1–2 weeks
• Bulk orders (100 pcs): approx. 6–8 weeks

Technical specifications

• Item Code: 3S-2IS
• Reference Cell: Monocrystalline silicon (31 mm x 31 mm)
• Current Shunt: High-precision shunt resistor soldered to cell terminals
• Irradiance Range: 0 – 1600 W/m²
• Uncertainty: ≤1% (≤2% as per IEC 61724-1 Class A)
• Resolution: 0.1 W/m² (≤1 W/m² as per IEC 61724-1 Class A)
• Response Time: 1 s (≤3 s as per IEC 61724-1 Class A)
• Drift: <0.3% / year
• Field of View: >160° (IEC 61724-1 Class A)
• Tilt-Azimuthal Angle: 0° - 0° (≤1°; IEC 61724-1 Class A)
• Output Rate: 1/s
• Data Output: RS485 up to 38400 Baud
• Communication Protocol: Modbus RTU
• Power Supply: 12 to 30 VDC
• Power Consumption: 25 mA max @24 VDC
• Electrical Connection: 3 m LIYYC11Y PUR cable, UV- and weather-resistant
• Galvanic Isolation: 1000 V between power supply and RS485 bus
• Cell Temperature Sensor Type: PT1000 Class A (EN 60751)
• Operating Temperature Range: -40°C to +85°C
• Operating Humidity Range: 0 to 100%
• Reference Cell Dimensions: 140 mm x 110 mm x 42 mm (W x L x H)
• Weight: 0.3 kg
• IP Rating: IP54 (IP65, IP68 options)
• Sensor Housing Material: Aluminum
• Calibration: Class AAA Sun Simulator per IEC 60904-2 and IEC 60904-4 using ISFH-Germany calibrated reference cell; tested under natural sunlight against Fraunhofer ISE reference cell.
• Connected External Sensors: 2× module temperature sensors (3S-MT-PT1000), 1× ambient temperature sensor (3S-AT-PT1000), 1× wind speed sensor (3S-WS-PLS)