SR300-D1 Pyranometer

SR300-D1: "industrial-grade" solar radiation monitoring

Hukseflux introduces “industrial-grade” solar radiation monitoring! The all-digital heated SR300-D1 pyranometer is engineered to measure solar radiation with the utmost reliability and measurement accuracy. SR300-D1 is the successor to our SR30-M2-D1 pyranometer, renowned worldwide as the ideal instrument for use in PV system performance monitoring.

• SR300-D1 continues to provide the measurement accuracy of the SR30. It may look like it as well, but in many ways the SR300-D1 is a completely new instrument, tailored for use in PV monitoring systems.
• SR300-D1 complies with – Industrial-grade – Immunity, Emission, Electrical, Environmental and Safety requirements for use in outdoor industrial environments, greatly improving measurement reliability.
• Ease of operation is further enhanced through extended functionality and diagnostics.

SR300-D1 complies with IEC requirements for “Class A” PV system performance monitoring, without the need for additional accessories. It includes: 
 

• onboard heating for dew and frost mitigation
• accredited pyranometer calibration within the required uncertainty limit
• calibrated tilt sensor accurate within ± 1 ° as required for single axis tracker fault detection and pyranometer tilt measurement

Immunity to high voltages and currents - surges

SR300-D1 is tested and classified for Industrial Environments according to IEC 61326-1 and IEC 61000-6-2. When designing a measuring system, SR300-D1 users may reach several levels of immunity.

With the optional Surge Protection Device SPD01 this immunity can be increased to 4 kV. Up to 3 pyranometers can be protected with a single SPD01. A third-party SPD with similar specifications may be used instead.

To attain the required level of immunity for a given installation, some general system components should be included, such as:

•    lightning protection system
•    earthing and grounding network
•    external surge protection in addition to the native on-board sensor protection

RS-485 isolation

The RS-485 interface of the industrial pyranometers is galvanically isolated from the internal electronics as well as from the instrument body. Both isolation barriers are rated at 1.5 kV. This contributes to reliable operation, flexibility in system design and reduced integration costs for all industrial pyranometers. 

Electrical safety in the workplace

A PV power plant is a potentially hazardous workplace environment. To comply with safety regulations, SR300-D1 features a dedicated earthing terminal for connection to protective earth. When the pyranometer is isolated from the mounting platform, it should still be properly earthed via this terminal. SR300-D1 allows system designers to comply with safety regulations. These are often based on EU and US electrical safety standards such as:

•    EN-50110 Operation of Electrical Installations
•    NFPA 70 National Electrical Code (NEC)

Tilt angle measurement

For PV systems with single-axis trackers, IEC 61724-1:2021 Class A systems also require a tilt angle measurement. The sensor used for this is an accelerometer. Every SR300-D1 accelerometer is individually calibrated, and temperature compensated from -30 to +50 °C, resulting in a high accuracy measurement in compliance with the required accuracy of ± 1 °. The acceleration components x, y and z can separately be read out to provide additional information about the instrument orientation.

Heated for high data availability, operation in 3 power modes

SR300-D1 includes a heater. Heating mitigates dew and frost, leading to high data availability.

SR300-D1 can be operated in 3 power modes. Overall performance in all 3 modes complies with ISO 9060 Class A classification criteria. This allows users to conserve power and continue the measurement, also when the system operating power is limited.

•    normal, < 3 W heated / ventilated for optimal dew and frost mitigation
•    medium, < 1 W unheated / ventilated for high accuracy measurement, when dew and frost are not an issue 
•    low, < 0.5 W unheated / unventilated to save power

Heating counters frost and dew deposition. In the picture on the right you see a clear difference between a heated and non-heated pyranometer

Remote diagnostics

In addition to solar irradiance, SR300-D1 outputs several alerts and measurements for remote use, most importantly:

•    alert: instrument leakage 
•    alert: change of tilt and rotation
•    alert: heating malfunction
•    internal humidity
•    internal pressure
•    instrument tilt and rotation

Remote diagnostics reduces the need for (un)scheduled field inspection.

On-site diagnostics: status LED

The status LED provides visual feedback to a local operator. On-site, users have immediate information on instrument power and data traffic. This is especially useful during installation and field inspections.