Hukseflux SR30-D1 User manual

Copyright by Hukseflux | manual v2005 | www.hukseflux.com | [email protected]
USER MANUAL SR30-D1
Next level digital secondary standard
pyranometer
Hukseflux
Thermal Sensors
compliant with IEC
61724-1:2017 Class A

SR30-D1 manual v2005 2/83
Warning statements
This manual supports model SR30-D1, the predecessor
of SR30-M2-D1. Need support for the new SR30-M2-D1?
Please refer to its separate user manual.
When SR30-D1 is installed using the recommended
SR30-M2-D1 wiring scheme, SR30-D1 RS-485
communication will NOT function reliably.
When SR30-M2-D1 is installed using the recommended
SR30-D1 wiring scheme, users will NOT benefit from
improved signal integrity.
Putting more than 30 Volt across the sensor wiring
of the main power supply can lead to permanent
damage to the sensor.
For proper instrument grounding: use SR30-D1 with
its original factory-made cable.
Using the same Modbus address for more than one
device will lead to irregular behaviour of the entire
network.
Do not operate with heater [ON] and ventilator [OFF]:
secondary standard specifications may not be met.
Disconnect power while performing service or
maintenance.
Modbus®is a registered trademark of Schneider Electric, licensed to the Modbus Organization, Inc.

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Contents
Warning statements 2
Contents 3
List of symbols 5
Introduction 6
1Ordering and checking at delivery 12
1.1 Ordering SR30-D1 12
1.2 Included items 13
1.3 Quick instrument check 13
2Instrument principle and theory 14
2.1 Operating modes: heating and ventilation 18
2.2 Overview of remote diagnostics 19
2.3 Use of the tilt sensor 19
3Specifications of SR30-D1 20
3.1 Specifications of SR30-D1 20
3.2 Dimensions of SR30-D1 25
4Standards and recommended practices for use 26
4.1 Classification standards 26
4.2 General use for solar radiation measurement 26
4.3 Specific use for outdoor PV system performance testing 27
4.4 Specific use in meteorology and climatology 27
4.5 General use for sunshine duration measurement 28
5Use of remote diagnostics 29
5.1 Recommendations 29
5.2 Sensor temperature 29
5.3 Tilt angle 30
5.4 Internal relative humidity 30
5.5 Heater current 30
5.6 Ventilator current 31
5.7 Ventilator speed 31
6Installation of SR30-D1 32
6.1 Site selection and installation 32
6.2 Installation of the sun screen 33
6.3 Installation of optional mounts 34
6.4 Installation of optional extension cable of 20 m 37
6.5 Electrical connection of SR30-D1: wiring diagram 38
6.6 Grounding and use of the shield 38
6.7 Connecting to an RS-485 network 39
6.8 Connecting to a PC 41
7Communication with SR30-D1 42
7.1 PC communication: Sensor Manager software 42
7.2 Network communication: function codes, registers, coils 42
7.3 Network communication: getting started 51
7.4 Network communication: example master request to SR30-D1 52
8Making a dependable measurement 55

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8.1 The concept of dependability 55
8.2 Reliability of the measurement 56
8.3 Speed of repair and maintenance 57
8.4 Uncertainty evaluation 57
9Maintenance and trouble shooting 60
9.1 Recommended maintenance and quality assurance 60
9.2 Trouble shooting 61
9.3 Calibration and checks in the field 63
9.4 Data quality assurance 64
10 Appendices 66
10.1 Appendix on cable extension / replacement 66
10.2 Appendix on tools for SR30-D1 67
10.3 Appendix on spare parts for SR30-D1 68
10.4 Appendix on the ventilator 68
10.5 Appendix on standards for classification and calibration 69
10.6 Appendix on calibration hierarchy 69
10.7 Appendix on meteorological radiation quantities 71
10.8 Appendix on ISO and WMO classification tables 72
10.9 Appendix on definition of pyranometer specifications 73
10.10 Appendix on terminology / glossary 74
10.11 Appendix on floating point format conversion 76
10.12 Appendix on function codes, register and coil overview 77
10.13 EU declaration of conformity 81

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List of symbols
Quantities Symbol Unit
Sensitivity S V/(W/m2)
Temperature T °C
Solar irradiance E W/m2
Solar radiant exposure H W∙h/m2
Time in hours h h
Tilt angle relative to horizontal θh°
Relative humidity RH %
Pressure p bar
Temperature coefficient a 1/°C²
Temperature coefficient b 1/°C
Temperature coefficient c -
(see also appendix 10.7 on meteorological quantities)
Subscripts
Not applicable

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Introduction
Welcome to the next level in solar radiation monitoring! The all-digital SR30-D1
pyranometer offers the highest accuracy and highest data availability: using new
Recirculating Ventilation and Heating (RVH
TM) technology, SR30-D1 outperforms all
pyranometers equipped with traditional ventilation systems. SR30-D1 is the ideal
instrument for use in PV system performance monitoring and meteorological networks.
This manual supports model SR30-D1, the predecessor of SR30-M2-D1. Need
support for the new SR30-M2-D1? Please refer to its separate user manual.
SR30-D1 measures the solar radiation received by a plane surface, in W/m2, from a 180 o
field of view angle. SR30-D1 is an ISO 9060 secondary standard pyranometer. It is
employed where the highest measurement accuracy is required. SR30-D1 offers several
advantages over competing pyranometers:
•Heated for best data availability: new RVHTM technology outperforms traditional
pyranometer ventilation
•The first pyranometer compliant in its standard configuration with the requirements for
Class A monitoring systems of the new IEC 61724-1:2017 standard
•Low cost of ownership: remote diagnostics and supported by an efficient worldwide
calibration and service organisation
•The right paperwork: instruments are supplied with the ISO 9060 required test
certificates
Figure 0.1 SR30-D1 next level digital secondary standard pyranometer

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Heated for high data availability, featuring new RVH
TM technology
High data availability is attained by heating of the outer dome using ventilation between
the inner and outer dome. RVHTM - Recirculating Ventilation and Heating - technology,
developed by Hukseflux, suppresses dew and frost deposition and is as effective as
traditional ventilation systems, without the maintenance hassle and large footprint.
•low power consumption: SR30-D1 requires only 2 W, compared to 10 W for
traditional ventilation systems
•low maintenance: SR30-D1 does not require filter cleaning
RVHTM uses SR30-D1’s built-in heater and ventilator. The dome of SR30-D1 pyranometer
is heated by ventilating the area between the inner and outer dome. RVH TM is much more
efficient than traditional ventilation, where most of the heat is carried away with the
ventilation air. Recirculating ventilation is as effective in suppressing dew and frost
deposition at 2 W as traditional ventilation is at 10 W. RVHTM technology also leads to a
reduction of zero offsets.
Compliant with IEC 61724-1: 2017, Class A and B
IEC 61724-1: Photovoltaic System Performance Monitoring - Guidelines for
Measurement, Data Exchange and Analysis - requires ventilation and heating for Class A
monitoring. Only SR30 offers both, without the need for additional accessories. Most
competing pyranometers do not even comply with Class B, which requires heating.
Low cost of ownership
SR30-D1 is an affordable secondary standard instrument and is designed for low cost of
ownership, which is mainly determined by costs of installation, on-site inspections,
servicing and calibration:
•low demand on infrastructure, SR30-D1’s RVHTM requires only 2 W power, compared
to 10 W for traditional ventilation systems
•reduction of unnecessary on-site inspection by remote diagnostics
•designed for efficient servicing; easy local diagnostics
•supported by an efficient calibration and maintenance organisation. Hukseflux offers
local support in the main global economies: USA, EU, China, India, Japan and Brazil.
Recalibration is recommended every 2 years, which is good practice in the industry.
Liabilities covered: test certificates
As required by ISO 9060 for secondary standard classification, each SR30-D1 is supplied
with test results for the individual instrument:
•sensitivity
•directional response
•temperature response
•tilt angle measurement

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Liabilities covered: test certificates
Remote sensor diagnostics
Besides solar radiation, SR30-D1 outputs sensor diagnostics, including:
•tilt angle
•sensor body temperature
•internal humidity
•internal pressure
•ventilator speed (RPM)
•ventilator current
•heater current
Remote diagnostics permits real-time status monitoring, reducing the need for
(un)scheduled field inspections.
Suggested use
Suggested use for SR30-D1:
•PV system performance monitoring
•scientific meteorological observations
SR30-D1 design
SR30-D1 pyranometer employs a state-of-the-art thermopile sensor with black coated
surface, two domes and an anodised aluminium body. SR30-D1 offers a digital output via
Modbus RTU over 2-wire RS-485. The pyranometer dome is heated by ventilating the
area between the inner and outer dome using RVHTM - Recirculating Ventilation and
Heating - technology.
Figure 0.3 Two SR30-D1 secondary stan-
dard pyranometers with digital output for
GHI (global horizontal irradiance) and POA
(plane of array) measurement applications
Figure 0.2Dew deposition and frost (as
in the photo): clear difference between a
non-heated pyranometer (back) and
SR30-D1 with RVHTM technology (front )

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Diffuse radiation measurement
With its outstanding zero offset specifications, SR30-D1 also is the instrument of choice
for high-accuracy diffuse radiation measurement.
Operating modes: heating and ventilation
The standard operating mode of SR30-D1 is with heater and ventilator both [ON]. The
power consumption then is 2.3 W. Alternatives are operation in medium power mode and
in low power mode. Heating and ventilation may be switched on and off by digital
control. If the heater is switched [OFF], SR30-D1 operates in medium power mode.
Operation at <0.1 W, in the lower power mode, is possible by switching both the
ventilator and heater [OFF]. Although zero offset will then increase slightly, overall
performance will still comply with the secondary standard classification. In case there is
no danger of deposition of dew or frost, the medium power mode offers the most
accurate measurement.
Communication with a PC: Hukseflux Sensor Manager Software
For communication between a PC and SR30-D1, the Hukseflux Sensor Manager software
can be downloaded. It allows the user to plot and export data, and change the SR30-D1
Modbus address and its communication settings. Also, the digital outputs may be viewed
for sensor diagnostics. See our separate Sensor Manager user manual.
Figure 0.4 User interface of the Sensor Manager, showing sensor diagnostics

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Options for mounting and levelling
There are two mounting options available for SR30-D1: a levelling mount and a tube
levelling mount. They allow for simplified mounting, levelling and instrument exchange
on either a flat surface or a tube.
Figure 0.5 Optional levelling mount (picture on the left); a practical spring-loaded
mount for easy mounting, levelling and instrument exchange on flat surfaces, and the
optional tube mount (picture on the right) including spring-loaded levelling upper clamp,
lower clamp for tube mounting and two sets of bolts.
Spring-loaded levelling
When opting for one of the levelling mounts, SR30-D1 is easily mounted and levelled
using the mount’s spring-loaded centre bolt and SR30-D1’s adjustable levelling feet.
Figure 0.6 Optional levelling mount allows spring-loaded levelling