Superintendent Magazine - October, 2012
Irrigation Association SuperTip: It's Time to Troubleshoot
Make sure to assess your irrigation system before preparing it for the winter
EDITOR'S NOTE: Superintendent magazine has teamed with the Irrigation Association for a bimonthly column, SuperTip, to focus on various water issues that affect golf course maintenance.
Now that the hot, dry part of the growing season is past, it's a good time to assess your systems before preparing them for winter. Taking the appropriate troubleshooting steps before winterization can save you time and potential damage to your system come spring. Your first step - before you go into the field - is to take the time to recap the season. Make a list of problems faced and what you did to resolve them, system failures and required repairs, modifications or additions, and lessons learned in terms of system operation.
Testing the system in the field
Once you've assessed the past season, make the time to walk and test the system.
- Locate and trim the grass around valve boxes, reachwells and quick coupling valves. The latter is especially critical if the valves are not located adjacent to a sprinkler head.
- Test air release valves for correct operation. These are an important part of any system that has PVC or HDPE pipe. If an air valve does not vent air properly or does not seal properly and weeps or leaks, it should be repaired. Mark the malfunctioning valve(s) on the record drawing. After the system is winterized, take the valves inside the shop and disassemble them. Remove any collected debris or pipe shavings. Make sure all internal parts move freely and that the valve seats properly. Reassemble the valves and reinstall them before spring start-up.
- Measure earth ground resistance at all ground rods and plates. Use a clamp-on ground resistance tester. These instruments are expensive, but most distributors have them and will usually test your grounds for a small fee. Record the ground readings (and the date they were taken) so they can be compared to initial and future readings.
- Test the resistance on solenoids and the related wiring. In decoder systems, the central software includes diagnostic routines for testing the condition of solenoids, decoders and the two-wire cables. In a conventional satellite system, disconnect the valve ("hot") wire and the common wire from the terminal strips in the satellite to get the most accurate readings. Measure and record the values using a digital multimeter. The readings can indicate failed (short-circuited) - or soon to fail - solenoids or wiring problems such as exposed and corroded splices. Table 1 gives the significance of various readings, but does not apply to special surge-resistant solenoids.
A normal reading for a healthy solenoid will be between 20 and 60 ohms, and most will be in the 24 to 32-Ohm range. Check a new solenoid in the parts room to get the actual reading to be expected from a healthy solenoid in your system.
Documentation and planning
- Document system weaknesses. Document areas of weak or excessive coverage, preferably with photographs and notes. If you wait until spring to make the needed changes, you'll need an accurate record of exactly where the problems were.
- Record system additions/modifications. Record any system additions or modifications so they can be correctly added to the record drawing.
- Update databases. Update the databases in the central controller to reflect changes made in nozzles or head types. If pipe and new heads have been added, the hydraulic tree will have to be updated. Many operational, programming and system shutdown problems are eventually traced to incorrect information in the databases.
- Schedule off-season staff training. Schedule training in irrigation maintenance and repair, electrical troubleshooting, and operation and programming of your central software. Colleges, trade schools, local distributors, manufacturers and the Irrigation Association provide these courses and some can be found online.
- Consider upgrading controller software. The off-season is the best time to make the change. Irrigation is not disrupted, and you can learn the system before you have to run it.
As the weather cools off and the need for constant use of the system lessens with reduced irrigation requirements, take these steps to troubleshoot your system, document the past season, and prepare for the off-season. In the end, the time you take now will help you preserve and maintain your system for the long run.
Jim Barrett, owner of the consulting and design firm James Barrett Associates Inc. in Roseland, N.J., is an IA board member, certified irrigation designer and certified landscape irrigation auditor.