Test equipment plays a crucial role in solar applications
As the world continues to become more environmentally conscious, photovoltaic systems (PV) are becoming increasingly more popular in the electrical industry. There has been an uptick in individuals wanting to fit their homes and businesses with this renewable energy source. With this comes the need for installation, maintenance and troubleshooting.
Install, Operate, Maintain
In North America, arrays are being designed and installed for use on rooftops with voltages up to 1,000 Vdc and mounted on the ground with voltages up to 1,500 Vdc. Many of these systems are installed and interconnected with the utility at distribution and transmission levels.
To meet the increasing needs of technicians in the industry who install this equipment, proper tools are essential to meet the requirements of testing and maintaining these systems. Field technicians need easy-to-use tools when working on PV systems. These devices must also provide system owners and operators the information required to maintain their investment. They also must be able to be used in all phases of installation, operation and maintenance, no matter the size of the PV array.
Verifying Performance of the Arrays
To correctly verify the performance of a solar array, various tests need to be run and data points need to be collected. One of the most important tests a PV system needs to go through is verifying that it is performing properly. Because the voltage output of PV modules is dependent on temperature, it is important for technicians to have a tool that includes a temperature probe so that they can measure the operating temperature of the modules. Megger’s digital clamp meter, the DCM1500S, includes this temperature probe as well as standard probes, alligator clamps and PV-specific MC4 leads. It has measurement capabilities up to 2,000Vdc and 1,000 Vac, non-contact voltage detection, as well as Bluetooth communications and recording.
Measuring the intensity of the sunlight striking the arrays is also key in knowing if the system is working properly. The amount of current a PV module can produce is directly proportional to the irradiance striking the array. This measurement is critical when validating the performance of a PV system, so it is important to test for this value. Technicians need the ability to correlate output from the array with the irradiance for accurate calculations on the array performance. Megger’s PVM210 can be used in conjunction with the amperage feature of the DCM1500S to quickly measure this.
Maintaining Your PV System
Tools are not just used for installing and operating your solar system. Operators and maintenance teams need to rely on the same tools as well as others to troubleshoot problems within the PV arrays. Field technicians need to use a good thermal camera to identify potential problems with the array or any inside piece of electrical equipment where poor connections may cause performance issues or fire. Megger offers a handheld unit that has a temperature range -20°C to 300°C, making it a valuable asset in discovering hotspots within individual modules that have failed in module junction boxes and poor electrical connections. The handheld camera, TC3231, is easy to operate and allows the technician to maintain a safe distance from the components being tested.
Looking for Hazards
Another important aspect of solar applications is to ensure that there are no ground faults present due to compromised wires. This test can be accomplished through using an insulation tester and should be completed before energizing your array at the commissioning stage, as well as during routine maintenance checks to monitor the integrity of your conductors.
Megger’s MIT2500 measures voltage, resistance and capacitance to help detect ground faults quickly so that there are no major delays or costly damage done like shock or fire. This tester has a wide range of testing voltages from 50 to 2500 V, making it ideal for use with PV systems.
Solar PV installations are becoming common practice. Individuals are working more and more on these systems through installation and maintenance. The Megger solar test kit can assist PV system technicians and electricians do their jobs safely and efficiently.