PV test

ACCREDITED CALIBRATION CENTER LAT NR 124 MEASURING INSTRUMENTS – REGULATORS DELTA OHM srl – Via Marconi, 5 – 35030 Caselle di Selvazzano – Padova – Italy Tel. +39.049.8977150 - Fax. +39.049.635596 - web www.deltaohm.com - deltaohm@tin.it P.IVA / COD.FISC. 03363960281 – R.E.A. 306030 – ISCR. REG. SOC. 68037/1998 TESTS ON THE FIELD FOR PV PLANTS There is no legislation to control of the proper functioning of pyranometers used to measure solar radiation installed in the PV field. The control can be effectively carried out with portable instruments suitable to avoid uninstalling pyranometers set in areas normally inaccessible as placed at the side of panels. A quick test on the field assesses whether a good maintenance is sufficient to obtain a reliable measurement of the solar radiation or if it is necessary to send radiation sensors to the manufacturer for a control. In order to make a test on the field and verify the proper operation of a photovoltaic system, Delta Ohm provides a set of tools that allow an easy and flexible use. NECESSARY MATERIALS: 1- Multiparametric 3-channels datalogger DO9847. 1- Secondary Standard Pyranometer LP PYRA 10 (or I Class Pyranometer LP PYRA 02 or II Class Pyranometer LP PYRA03). 1- SICRAM module VP472. The signal generated by the thermopile of the pyranometer installed in the plant and to be verified can be read in mV or W/m2. The sensitivity of the thermopile can be set from 5 toa 30µV/(Wm-2). 2- CPM12 AA4.5 Cable. 4-pole cable. 5m long. M12 poles connector on once, open wires on the other. MEASURING INSTRUMENTS – REGULATORS STRUMENTI DI MISURA – REGOLATORI DELTA OHM srl – Via Marconi, 5 – 35030 Caselle di Selvazzano – Padova – Italy P.IVA / COD.FISC. 03363960281 – R.E.A. 306030 – ISCR. REG. SOC. 68037/1998 SRL1- IP 472 SICRAM Module. Electronic module for reading and acquiring CONTINUE CURRENT. Measuring range: 0 ... 24mA, input impedance: 25O. PROCEDURE: 1- Make sure you are on a sunny day and clear of clouds. 2- Carry out maintenance and cleaning of the pyranometer disk installed in the plant. 3- Connect the instrument to channel A of the multiparametric DO9847, the reference LP PYRA 10 bymeans of the SICRAM module VP 472. The connection must be made with the cable CPM12 AA4.5. 4- Disconnect the wiring of the pyranometer to be verified. Connect channel B of the DO9847 to the SICRAM Module IP 472 and connect to the pyranometer you want to verify by using cable CPM12 AA4.5 (ensure the correct power supply of the pyranometer installed, which can be made for example by using two 9V batteries in series). 5- Capture and store data of the two instruments at intervals of 20 seconds (or less) for at least 10 minutes (or more). 6- Download data to the PC and verify the proper functioning of the pyranometer tested by comparison using Excel program. The acquired value in mA of the instrument under test will be converted to solar irradiance Ee (W/m2) by using the following formula: ( )mAIe outE 4125 -·= MEASURING INSTRUMENTS – REGULATORS STRUMENTI DI MISURA – REGOLATORI DELTA OHM srl – Via Marconi, 5 – 35030 Caselle di Selvazzano – Padova – Italy P.IVA / COD.FISC. 03363960281 – R.E.A. 306030 – ISCR. REG. SOC. 68037/1998 SRLwhere: Ee: is Irradiance in W/m2, Iout: is current in mA absorbed by the instrument 7- Optionally, you can also acquire the temperature measurement of the panel by using the flat probe TP 878.1.O connected to the channel C of the DO9847