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SUMMARY: • Commissioning is the time when the installer demonstrates system operation and formally transfers responsibility for the system to the owner or operator. • A general start-up procedure begins at the array and ends at the loads, though certain components or system configurations recommend different procedures. • It’s critically important to review all equipment documentation for any special start-up procedures. • Interactive systems require the least maintenance while stand-alone and hybrid systems, because they include batteries or additional power sources, require maintenance that is more extensive. • Simple and nonhazardous maintenance may sometimes be performed by the system owner. Advanced maintenance tasks, including troubleshooting and equipment servicing or replacement, usually requires the experience and expertise of a qualified installer or service technician. • Shading conditions can change over time, so routine maintenance may be required to control excessive shading. • Sealant cracks or loss, broken gaskets, and bent metal flashings are all signs of weather sealing degradation, which can quickly result in roof leaks. • Batteries are usually the most maintenance-intensive components in any PV system. • Battery maintenance tasks include cleaning, tightening terminals, watering, and checking battery health and performance. • Battery state of charge is estimated by specific gravity or open-circuit voltage measurements. • PV-system maintenance should be carefully planned and documented to ensure that the necessary tasks are being performed on the required schedule. • PV-system monitoring provides information about system performance and status and alerts persons to possible problems. • Power, voltage, and current are the basic indicators of array and inverter performance and these measurements are extensively used to troubleshoot problems. • Data acquisition facilitates spotting trends and correlations between parameters and is particularly useful for troubleshooting. • Troubleshooting procedures are designed to identify malfunctions by examining the system at progressively narrower levels. • When troubleshooting has successfully identified the cause of the problem, it’s important to document the results. TERMS: • Commissioning is the starting and operation of a PV system for the first time. • Delamination is the separation of the bonded layers of glass and/or plastic encasing the PV cells of a module. • Soiling is the accumulation of dust and dirt on an array surface that shades the array and reduces electrical output. • A hydrometer is an instrument used to measure the specific gravity of a liquid. • A battery load tester is a test instrument that indicates battery health by drawing a high discharge current from a battery for a short period. • A maintenance plan is a checklist of all required regular maintenance tasks and their recommended intervals. • A maintenance log is a collection of past maintenance records. • Monitoring is the repeated measurement of electrical, environmental, or battery parameters at certain intervals. • Data acquisition is the recording and processing of data from a monitoring system. • Troubleshooting is a systematic method of investigating the cause of system problems and determining the best solution. • A troubleshooting level is the depth of examination into the equipment or processes that compose a system. EXAM: 1. Why should PV systems be commissioned by using a careful start-up sequence? 2. Why might start-up procedures vary for different PV systems? 3. What should be included in the system documentation package? 4. What factors are involved in the long-term control of array shading? 5. What tasks are typically involved in battery maintenance? 6. What factors affect the frequency of battery watering? 7. Why is electrolyte specific gravity measured? 8. How is a maintenance plan developed? 9. How are data-acquisition records particularly useful when troubleshooting? 10. Why is it sometimes unnecessary to troubleshoot beyond the component level? 11. What is involved in the observation step when troubleshooting? Next: Prev: Troubleshooting |