Safety is the most important aspect of PV maintenance. Stick to the safety
requirements that apply when installing a PV system. PV system maintenance
involves tasks such as:
Visual inspections
Cleaning
Assessing operational data
Fixing problems, if necessary
Fixing problems is easy, especially if you know where they are and how to
find them. Problems may not be so obvious and require observation and trouble-
shooting. Troubleshooting is a deductive process of cause, effect, determination,
and elimination. Sherlock Holmes once said, “…when you have eliminated the
impossible, whatever remains, however improbable, must be the truth.”
Troubleshooting is a logical process that systematically identifies problems and
implements the best course of corrective actions. It is often a process of elimina-
tion. Troubleshooting can avoid wrong diagnoses. It also can minimize purchasing
unnecessary replacement parts and cut down on costs required to fix the problem.
Start routine PV system maintenance with a functionality test. There are four
phases of the functionality test—start-up, shutdown, normal operation, and emer-
gency/bypass operation. All PV systems have different functionalities and opera-
tional parameters based on design, components, configuration, and size.
Breakdowns and irregularities in the functional tests help determine the specific
components to be addressed. Review the specific components’ instruction manuals
for information on installation, operation, troubleshooting, and maintenance.
Array and Battery Maintenance
Array Maintenance
Examine PV arrays annually. Look for the following, and document conditions:
Module discoloration
Structural components
Attachment methods and weather sealing
Electrical connections
Grounding
Corrosion elements and shading
Electrical output of PV arrays
Inspect PV array, string, and PV module structural components. Check
structural security and foundations. Make sure all mechanical attachments are
properly torqued. Tighten any loose fasteners. Loose fasteners can bend, break, or
rust. Rusting can cause orangish-brown streaking on roofs and along building
walls if steel products are used.
240 ADVANCED PHOTOVOLTAIC INSTALLATIONS
Although the array is often considered a low-maintenance component, it is not a
no-maintenance component. This array will need cleaning and inspection of the mechanical
connections. It was designed to allow for maintenance to the roof.
Courtesy of PerfectPower, Inc.
This panel speaks for itself. A panel this dirty can lose 5 to 10 percent of its ability to produce
energy. Cleaning is simple and basic to all systems.
Courtesy of PerfectPower, Inc.
CHAPTER 10 Quality Control, Testing, Troubleshooting, Monitoring 241
Check attachments or penetrations through building surfaces for any
possible water or air leakages. Weather-seal any attachments or elements that pen-
etrate a building surface. Reapply weather sealing as needed to prevent damage.
Inspect array wiring as part of array maintenance. Array wiring and other
electrical components are critical to PV system performance. Bundle and tie up
electrical wiring neatly. Hide electrical wiring from the sun and away from fin-
gers. Wiring also can be a visual distraction.
Look for insulation damage, cuts, cracks, nicks, and connector damage. Use
inter-module connections that are polarized, guarded, and weather-sealed. They
have a special locking mechanism that requires a special tool to open them. Inter-
module connections require power termination to eliminate arcing damage to the
connection. All inter-module connections should be marked “Do Not Disconnect
Under Load.”
Examine PV module and array grounding and equipment bonding connec-
tors and terminations. Check for corrosion on the support structure’s electrical
grounding. Use a jumper if a module needs to be removed for service. Inspect
grounding and bonding connections at every scheduled maintenance.
Examine conduit supports and attachments at every scheduled maintenance
as well. Conduit can buckle or contract depending on the PV site temperature.
Conduit can separate at the couplings if not properly sized. Allow for expansion
and contraction within the conduit. Ensure that the combiner box cover and all
gaskets have appropriate electrical wiring and connection protection.
PV modules and support structures are exposed to weather conditions on a
daily basis. Exposed equipment is likely to be damaged. Damaged modules will
produce power as long as the laminate or glass and electrical connections are not
broken, and as long as the electrical connections are not broken. Any breaches in
the module will cause current leakages, soak up water, and start to fail. Broken
modules can cause an electrical fire.
Shading reduces PV array performance. Confirm that the
modules are clean. Remove any dirt, bird droppings, and veg-
etative debris. Take the time to trim any vegetation that may
block the PV array’s ability to capture sunlight. In some cir-
cumstances, remove trees or relocate the array. Shading from
grasses, shrubs, and other vegetation greatly affects the elec-
trical output by the PV array.
When PV arrays become dirty, electrical output can diminish by 5 to 20 per-
cent. All arrays need to be cleaned at least annually, with most requiring quarterly
cleaning—and some near freeways, airports, or industrial areas may require more.
Clean PV arrays with a high-pressure hose nozzle for a general cleaning or with a
long-handled soft bristle brush at least annually and a pressure washer on a low
setting for a more thorough cleaning. Use only recommended cleansers for PV
arrays to remove built-up soil, oily deposits, and grime.
TECH TIPS
If the array ground-fault
protection circuit starts to trip, check
the array surface for discoloration and
damage.
242 ADVANCED PHOTOVOLTAIC INSTALLATIONS
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