RS485 solar radiation sensor 3S-2IS

Modbus RTUModbuswith temperature sensor

Product Overview
The SEVEN 3S-2IS is a dual-orientation irradiance sensor engineered to calculate the Performance Ratio (PR) of PV plants with two orientations. It measures sunlight on two planes using two calibrated monocrystalline silicon reference cells and computes a panel-number-weighted average irradiance. The unit supports simultaneous connection of two irradiance sensors, two module temperature sensors, one ambient temperature sensor and one wind speed sensor.

How it Works
Each monocrystalline reference cell measures irradiance on its plane. The built-in microcontroller accepts the number of modules per orientation via the configuration interface and calculates the Total Effective Irradiance as a panel-number-weighted average. PT1000 sensors on each reference cell provide continuous temperature compensation to maintain IEC Class A accuracy. Total Effective Irradiance and temperature data are output via Modbus RTU (RS485) and can be integrated with dataloggers, SCADA systems and monitoring platforms (SunSpec supported where applicable).

Key Features

• Dual-plane measurement: simultaneous irradiance measurement on two surfaces and computation of effective irradiance.
• Modbus plug-and-play: RS485 Modbus RTU interface for easy integration with common dataloggers and inverters.
• IEC Class A compliance: calibration and performance according to IEC 61724-1 and IEC 60904 procedures.
• Expandable inputs: supports module temperature, ambient temperature and wind speed sensors for complete environmental data.
• Field-ready design: aluminium housing with IP54 protection (IP65/IP68 options) and 3 m UV-resistant LIYYC11Y PUR cable.
• Low power consumption and long-term stability; five-year warranty.

Supported External Sensors

• 2× Module temperature sensors (3S-MT-PT1000)
• 1× Ambient temperature sensor (3S-AT-PT1000)
• 1× Wind speed sensor (3S-WS-PLS)

Documents
Datasheet, User Manual and Model Selection Table are available in the product files.

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% per IEC 61724-1 Class A)
• Resolution: 0.1 W/m² (≤1 W/m² per IEC 61724-1 Class A)
• Response time: 1 s (≤3 s per IEC 61724-1 Class A)
• Drift: <0.3% / year
• Field of view: >160° (IEC 61724-1 Class A)
• Tilt-azimuth angle: 0° - 0° (≤1° per IEC 61724-1 Class A)
• Output rate: 1/s
• Data output: RS485 up to 38400 Baud
• Communication protocol: Modbus RTU (SunSpec supported)
• Power supply: 12–30 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: PT1000 Class A (EN 60751)
• Operating temperature: -40°C to +85°C
• Operating humidity: 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: Aluminium
• Calibration: Calibrated under Class AAA sun simulator per IEC 60904-2 and IEC 60904-4 using an ISFH-Germany calibrated reference cell; tested under natural sunlight against Fraunhofer ISE reference cell.