1. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 1 2-11. Preventive Maintenance

2. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 2 Preventive maintenance Maintenance is of two types: –Preventive maintenance is carried out on operating systems and is intended to reduce the risk of failure –Response maintenance is carried out where a problem has occurred and maintenance has to be carried out to fix the problem. This may also be called repair maintenance Preventive maintenance is vital for solar systems because failure is usually the result of many small problems that could mostly be prevented. Proper preventive maintenance only takes 15-20 minutes to complete but will do much to ensure long, reliable life of the components.

3. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 3 Activities (1) Clean, clean, clean. Many problems occur because of accumulation of dirt and corrosion –Clean the battery and check connections. Add protective grease to connections if needed. –Clean out battery cap vent holes so charging gas can be released from the cells –Clean and check connections if there are visible problems –Clean the lights –Clean panels if needed

4. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 4 Activities (2) Check battery for voltage and take hydrometer readings to see if cells are equal and if battery charge seems normal under the conditions existing at the time of the visit. Fill the battery to the proper level with pure water. Do not overfill. Periodically check the voltage drop at switches to see if any have a voltage drop over 0.05V when switched on.

5. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 5 Activities (3) Interview the user to see what is felt to be the status of the system. If there are problems try to determine why. If the condition of the battery indicates possible controller malfunction, check the controller. Check to see if additional appliances have been connected to the system Examine the panel to see if the mounting remains solid and the wires properly attached

6. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 6 Activities (4) Check the wiring to see if it has become detached from the building. If there are underground wires, check to be sure the pipes remained properly sealed with silicone rubber If problems are uncovered, correct them on the spot if possible.

7. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 7 Record keeping For every installation there should be a list of components and their serial numbers. A wiring diagram should be made. These papers should be copied for storage at the main office and copies kept at the installation Any time components are repaired or changed, a note of the action taken should be made so it is clear what components are causing problems and to bring site records up to date with corrections also made to the office copies.

8. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 8 Monitoring Because battery problems may take months to show up clearly, there needs to be a continuing record of battery measurements (voltage, time and date of visit, hydrometer readings for each cell, and the amount of water needed by the battery) so problems that are increasing in severity can be easily identified by comparing prior readings.

9. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 9 2-12. Troubleshooting

10. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 10 Know how the system is supposed to work When the system is new and working well, disconnect the panel from the controller and check amperes on a sunny day so you can later make the same measurement and know if the panel is working properly or not. When the system is new measure the voltage drop at all switches so you can tell if they are getting worse over time

11. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 11 Types of failures for SHS Total failure, no power day or night Partial failure, power for some appliances during the day but not at night Reduced capacity, the system works ok but for an unacceptably short time. Abnormal characteristics (fast water loss, some appliances don’t work while others do, etc.)

12. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 12 Total failure – Battery discharged below LVD cutoff When there is no power available the possible problems are: –Panel wires disconnected or broken.  Disconnect the panel at the controller and measure Amperes from the panel to see if current flow is normal. Voltage measurements are NOT adequate for checking the panel. –Controller not charging the battery  Voltage at controller panel connections normal for charging but voltage at battery connections is below the LVD voltage –Battery connection loose –Battery failure

13. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 13 Total failure. Battery has low charge but is above LVD Cutoff voltage Low voltage disconnect has activated due to low battery and the battery charge has not recovered enough to reset. Battery connection loose Fuse blown

14. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 14 Total Failure. Battery has reasonable charge Fuse at battery blown. Wiring between battery and controller has a problem Battery connection loose LVD control cut off appliances and did not reset.

15. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 15 Partial Failure No power at night, some power during the day –Battery failure (open circuit) so during the day the panel operates some appliances directly but the battery does not charge –Battery disconnected or loose connection. –Battery fuse blown Some appliances work some do not. –Switch failure –Loose connection –Appliance failure

16. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 16 Reduced capacity Increased shading Charge Controller cuts off the charge at too low a voltage (check battery voltage when fully charged) LVD cuts off the load at too high a voltage (check battery voltage when power disconnects) Loose connection at panel, controller or battery Unusually long period of cloudy weather User has increased appliance use and is running the system down faster Battery is damaged and has lost capacity (consider battery age and knowledge of its history, do a simple capacity test).

17. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 17 Causes of inadequate system capacity Panels: Shading, incorrect orientation, loose connections, damaged panel Controller: Charge set point too low, LVD set point too high Wiring: Bad connection in Panel to Battery circuit, high voltage drop in switches, wires too small User: Excessive use. Battery: Loss of capacity due to sulfation or repeated deep discharge, loose connection, low electrolyte, old age

18. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 18 Battery Replacement Before replacing a battery be SURE all the rest of the system is operating properly. Installing a new battery in a poorly working system dooms the new battery to early failure If the battery is shown to be bad, replace it and recondition all the rest of the system including: –Full checks of the controller to be sure it is working correctly –Cleaning and restoring all connections to new condition –Checking all wiring for proper attachment to the building and proper location of wire fasteners –Check all wiring for proper sizing –Check panel mount for orientation, corrosion and any need for repair to maintain needed storm resistance –Check of all appliances for proper Ampere draw and correct operation. –Check for possible shading increases considering the different locations of the sun over the year.

19. e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 19 What’s Wrong in this Picture? What’s right?