California Friendly Landscape Training Irrigation Course Irrigation System Troubleshooting Course originally developed by California Polytechnic State University, San Luis Obispo Irrigation Training & Research Center (ITRC) http://www.mwdh2o.com
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Table of Contents I. Class 2 Troubleshooting Course Description...1 Presentation...2 Basic Valve Repairs...22 Controller Output Voltage...24 Continuity Controller to Control Valve...26 Continuity Control Valve to Controller...27 Solenoid Continuity...28 Wire Splice...29 Wire Nut Splice...31 Multimeter Exercise...33 Field Exercise...34 iii
Course Description California Friendly Landscape Training Program Course Description The course consists of six (4) consecutive classes in landscape water management, each building upon principles presented in the preceding class. The California Friendly Landscape Training Program begins with basic irrigation principles of soil-plant-water relationships, and concludes with irrigation scheduling. Every participant will receive a course handbook. The following is a synopsis of each class. 1. Irrigation Principles, System Adjustment & Repair: A comprehensive workshop addressing the principle factors in landscape irrigation. Concepts presented here are the foundation to sound landscape water management. Topics include plant water needs, soil characteristics, and types of irrigation. Demonstrations illustrate how to determine plant water needs, how to manage irrigation in various types of soil, and also provide a graphic understanding of precipitation rates and how they affect irrigation system uniformity. Participants will learn the importance of regularly adjusting irrigation systems and the value of the early detection and repair of irrigation system problems. Principles shared also emphasize the negative impact of poorly adjusted irrigation systems on water use, plant health, irrigation uniformity, and damage to surrounding property. Hands-on demonstrations enable participants to practice these principles by making adjustments and repairs to a portable irrigation system. 2. Irrigation System Troubleshooting: This session focuses on the analytical approach to solving irrigation system failures. Three areas of potential problems are examined: mechanical, hydraulic, and electrical. Workshop participants will receive practical training in the use of electrical troubleshooting equipment, as well as an opportunity to demonstrate these skills during the hands-on portion of the session. 3. Controller Programming: A fully hands-on workshop in which an Irritrol MC Plus irrigation controller will be provided per two class participants. They will learn basic controller features while programming sample cases in the class. Also, participants will be exposed to advanced controller features as they implement schedules which take into consideration temperature/seasonal changes, rain, and landscape activities or demands which limit irrigation times. 4. Irrigation Scheduling: This session focuses on two critical questions: When to irrigate? and How much water to apply? A variety of field techniques and methods are presented as well as technical aspects to be considered while scheduling irrigation. Each class participant will be furnished with tools to use while scheduling landscapes for which they may be responsible. Participants will receive a certificate denoting the classes they attended upon completion of the course. The California Friendly Landscape Training Program course was developed by the Irrigation Training and Research Center at California Polytechnic University in San Luis Obispo, and is funded and presented by the Metropolitan Water District of Southern California. 1
California Friendly Landscape Training Irrigation System Troubleshooting California Friendly Landscape Training Workshop 1: Irrigation Principles & System Adjustment and Repair Workshop 2: Irrigation System Troubleshooting Workshop 3: Controller Programming Workshop 4: Irrigation Scheduling Today s Workshop Irrigation System Troubleshooting Electrical Concepts Field Skills Electrical System Mechanical Operation Troubleshooting Steps 2
Water Efficient Devices Rotating Nozzles Smart Sprinkler Controllers Synthetic Turf Goal of Today s Workshop To open and close the valve with the irrigation controller! Controller Valves Electrical Concepts Current Voltage Resistance All these are related, but they re not the same thing! 3
Current Current is the movement or flow of electrons Amps Current activates the valve solenoid Wire Current: rate of speed of electrons Voltage Voltage is the force that pushes electrons through the wire Volts (VAC or VDC) Wire Voltage: Force that pushes electrons Types of Voltage Direct Current (VDC) Flow is in one direction from batteries Alternating Current (VAC) Flow alternates direction typical electrical systems 4
MWD California Friendly Landscape Training Resistance Resistance to flow of electrons Affected by wire size and length Measured in Ohms (symbol Ω) Wire Smaller Wire Higher Resistance lowers amount of Current to Solenoid! For Troubleshooting... Need to measure Voltage (Volts) to check the Controller Need to measure Resistance (Ohms Ω) to check the wiring, solenoid, and connections Controller Valves Typical Electrical System Irrigation Controller Common Wire 24-28 VAC 110 VAC 24-28 VAC With Step-Down Transformer Valve Solenoid(s) 5
Controller 110 VAC supply voltage very dangerous! Flows through step-down transformer 24 VAC Volts output to control valves Controller switches open and close valve circuits Typical Voltage 110 VAC Supply to Controller 24 VAC From Controller to Valves Measurements Volt-Ohm Meter Multi-Meter Check Mate 6
Voltage Measurements Meter Setting Probe Placement Safety Safety 120 Volts very dangerous! Experienced personnel only 24 Volts not dangerous But be careful work with caution Measuring Voltage - VAC Tip: disconnect the common wire from the terminal 7
MWD California Friendly Landscape Training Input and Output Voltage Valves Output 24-28 VAC Input 110 VAC Controller Output 24-28 VAC Voltage Output Problems If less than 24 Volts: The controller station switch may be faulty If more than 28 Volts: The transformer may be faulty may need to replaced If voltage output is OK, check field circuitry next... Control Circuit Two Wires Control Wire Switched, Open or Closed Common Wire Common Wire Control Wires 8
Measure Resistance to Check Circuits Resistance in Wire (Conductors) Resistance to electrical movement Wire size and length Units OHM (Ω) Resistance Readings Wire - 1,000 feet of 14 gauge wire 3 Ohms (approx.) Solenoids different manufacturers 20 to 60 Ohms for most solenoids Some have very high readings (Griswold) Resistance of Solenoid 9
Wiring Problems Wiring problems that resist the amount of current to the solenoid Broken Wires Inside the Solenoid Control Wire Common Wire Bad Connections Solenoids Junction Boxes At the Controller Damaged Wires During Installation Other construction done after installation of wires (fences, trenches, etc.) Tree Roots Animals Steps and Safety Power OFF! Damage the multi-meter Tip: disconnect common Set meter scale high One probe at common wire Other probe at control wire Begin test Resistance Reading 10
Circuit Condition 1. Closed Complete/Good Circuit 2. Open Circuit Fault 3. Partial Open Circuit Fault 4. Short Circuit Fault 1. Complete (Closed) Circuit Functioning properly Proper flow of electricity between Controller and Control Valves There are no wire breaks, shorts, or bad connections Complete Circuit Typical Response Closed/Complete Circuit: Resistance Reading: 20-60 Ohms Normal 11
2. Open Circuit Fault There s a break in the circuit Break in the wiring Break inside the solenoid A connection came apart Open Circuit Typical Response Open Circuit Fault: Maximum Resistance, infinite Ohms 1 on left side of display (digital meters) This circuit will not operate 3. Partial Connection Circuit wires make partial connection at: Controller Control Valve No waterproof connectors Nicked or damaged wires (not completely broken) 12
Partial Connection Typical Response Partial Connections Fault: Resistance: higher than normal Ohms Erratic system performance 4. Short Circuit Fault Common wire and Station (Control) wire make contact Solenoid interior coil wires make contact Short Circuit Typical Response Short Circuit Fault: Fuse will burn or breaker will trip Resistance Reading: 0 to 10 Ohms This circuit may come on with other valves 13
Summary of Circuit Conditions Circuit Condition Resistance - Ohms 1. Closed Circuit 20-60 Ω 2. Open Circuit Maximum Ω 3. Partial Connection Higher than normal 4. Short Circuit 0-10 Ω Waterproof Connectors Black Box Exercise Notes: Simulation of circuit conditions Closed Circuits Open Circuits Partial Connections Short Circuits 14
?Questions? Electrical Troubleshooting Mechanical Troubleshooting Water Supply Valve Operation Valve Closed 15
Valve Opening Valve Open Flow Control Bleeder Screw Outlet Port Valve Spring Valve Body Inlet Port Diaphragm Stopper Valve Seat 16
Common Valve Problems Cracked diaphragm Broken spring Plugged inlet port Calcium deposits inside solenoid Rocks or debris on stopper seat Valve will not Open Insufficient Voltage Hole on the diaphragm (Reverse Flow Valves) Flow stem is closed Plunger is stuck or missing Outlet port is plugged Bad Solenoid Valve will not Close Hole on the diaphragm (forward flow valve) Debris on the valve seat Flow stem turned up too high Inlet port gets plugged during operation 17
Valve Assembly Class Exercises Disassemble Valve Reassemble Valve Wiring from Top of Valve Removed Screwing off Top of the Valve 18
Spring Removed from Valve Diaphragm Empty Valve Housing 19
Reassembled Valve Look for the obvious first Is the water turned on? Is the controller plugged in? Is the timer programmed correctly? Is there an isolation valve??questions? 20
California Friendly Landscape Training Your hosting water agency would like to thank you for being water conscious and attending this Workshop 21
Basic Valve Repairs 1. Preparation Make sure controller is off. Make sure water supply is off. 2. Solenoid Inspection Remove solenoid and plunger from upper valve housing. Look for debris that might be causing the solenoid plunger to stick. Inspect solenoid plunger and seat for nicks or cuts. Replace if any signs of nicks or cuts. 3. Remove Valve Top Remove screws around top half of valve. Turn screws counter-clockwise to remove. Carefully remove the valve top to uncover the spring and diaphragm. Look for any debris that may be interfering with the free movement of diaphragm or center guide pin. 4. Valve Inspection Inspect the spring for bends or brakes. This could cause the valve to take a long time to close. Replace if necessary. 22
Basic Valve Repairs 5. Valve Inspection Inspect the diaphragm for cracks or holes. Pull diaphragm from center to outside to reveal any hidden cracks. Replace if any sign of cracks. 6. Valve Inspection Inspect the diaphragm bleed hole for debris. Clean out debris; be careful not to damage diaphragm. Replace if damaged. 7. Valve Inspection Make sure passage from top of valve inside chamber to solenoid port is open. Clean out if plugged. 8. Valve Assembly Reverse disassembly procedure. Make sure diaphragm is flat and not twisted or bent when top housing is installed. All gaskets and "O" rings are in place. 23
Controller Output Voltage 1. Set-Up Insert leads into terminals - COM + V- Ω- A Turn selector to "AC V". 2. Prepare For Test Disconnect common wire on controller. Using alligator clip, connect meter lead to common terminal. 3. Operate Controller Select stations to be tested. Manually turn on station to be tested. 4. Read Controller Voltage One lead is connected to common terminal. Touch the remaining lead to station terminal being tested. Read voltage. 24
Controller Output Voltage 5. Typical Response 23 to 30 VAC - Controller OK. Less than 23 VAC controller has a problem. Zero Volts, make sure: Controller has power Station being tested is on Controller has Problem 25
Continuity Controller to Control Valve 1. Prepare for Test Insert leads into terminals - COM + V- Ω- A Turn selector to Ω portion of meter. Place touch probe ends and adjust meter to read zero. 2. Set-Up for Test Disconnect common wire on controller. Using alligator clip, connect meter lead to common wire. 3. Read Circuit Resistance One meter lead is connected to common terminal. Touch the remaining meter lead to control wire being tested. Read resistance. If needle goes off scale, move selector to next highest scale. Repeat this process until you are able to read dial or you have reached the largest scale. 4. Typical Response Maximum reading - open circuit. 20 to 35 Ω reading - normal operation. Zero ohms - short circuit. Reading greater than 20 to 35 ohms indicates partial open. Reading between 0 and 20 to 35 ohms indicates partial short. 26
Continuity Control Valve to Controller 1. Prepare for Test Insert leads Into terminals - COM + V- Ω- A Turn selector to Ω portion of meter. Place touch probe ends and adjust meter to read zero. 2. Set-Up for Test Disconnect common wire on controller. Using alligator clips, jumper the control wire and the common wire. Disconnect solenoid. Remove insulation from control and common wires. 3. Read Circuit Resistance One lead is connected to common wire. Touch the remaining lead to control wire being tested. Read resistance. If needle goes off scale, move selector to next highest scale. Repeat this process until you are able to read dial or you have reached the largest scale. 4. Typical Response Maximum reading - open circuit. 0 to 5 Ω reading - normal operation. Depends on length and size of wire. Zero ohms - short circuit. May be a short, but with very small wire length the reading could be OK. Greater than 5Ω reading - may indicate a partial closed or poor connection. 27
Solenoid Continuity 1. Prepare For Test Insert leads into Terminals - COM + V- Ω- A Turn selector to Ω portion of meter. Place touch probe ends and adjust meter to read zero. 2. Set-Up for Test Disconnect solenoid from control and common wire. Remove insulation from solenoid wires. 3. Read Circuit Resistance One meter lead is connected to a solenoid wire. Touch the remaining meter lead to control wire being tested. Read resistance. If needle goes off scale, move selector to next highest scale. Repeat process until dial can be read or largest scale is reached. 4. Typical Response Maximum reading - open circuit. 20 to 35 Ω reading - closed circuit normal condition. Zero ohms - short circuit. Reading above 30 ohms indicates partial open. Reading between 0 and 20 ohms indicates partial short. 28
Wire Splice 1. Locate Cut Use the portion of the cutter jaws which is appropriate for the wire size being cut. Make sure blade and cutter jaws are perpendicular to wire. 2. Continue Cutting Using the portion of the cutter jaw with the correct wire size, close the blade of the cutter. It may be necessary to repeat this a couple of times while rotating the cutters around the wire. 3. Removing the Installation Close the blade of the cutter. Pull the cutter toward the end of the wire. 4. Trim Wire Trim wire ends so that there is an equal length of bare wire. Twist individual wire ends to consolidate lose wire strands. 29
Wire Splice 5. Start Wire Splice Insert the two wires through the top of the outer housing. Twist the two wires together. 6. Connect Wire Insert two wires into copper ring. Crimp the copper ring onto the end of the two wires. Pull on wires to make sure the crimp is tight. 7. Complete Splice Push the connected wires into the body of the splice. Press the cap and body together to complete the splice. 30
Wire Nut Splice 1. Locate Cut Use the portion of the cutter jaws which is appropriate for the wire size being cut. Make sure blade and cutter jaws are perpendicular to wire. 2. Continue Cutting Close the blade of the cutter. It may be necessary to repeat this a couple of times while rotating the cutters around the wire. 3. Removing the Installation Close the cutter blade. Pull the cutter toward the end of the wire. Insulation should slip from the wire; if it does not repeat the cutting the process. 4. Trim Wire Trim wire ends so that there is an equal length of bare wire. 31
Wire Nut Splice 5. Complete the Splice Insert the two wires into the wire nut. Twist nut until tight. Test connection by pulling back on the wires and wire nut. 32
Multimeter Exercises MULTIMETER EXERCISE I. Ohms Steps: 1. Set Multimeter selector switch to Ohms Ω. 2. Take Ohms readings on each of the four "Black Boxes" and write down the readings in the table below. 3. Circle the problem of each box based on the Ohm readings you just made. (Remember: An OK coil has a resistance of 20 OHMS) Box Number Reading in OHMS Problem (Circle One) 1 (Open) (Short ) (Partial Open) (Partial Short) (OK) 2 (Open) (Short ) (Partial Open) (Partial Short) (OK) 3 (Open) (Short ) (Partial Open) (Partial Short) (OK) 4 (Open) (Short ) (Partial Open) (Partial Short) (OK) 33
Field Exercises TROUBLESHOOTING FIELD EXERCISE Neutral Neutral Station #1 or #4 Station #2 or #5 Neutral Station #2 or #6 To Controller I. Controller hookup 1. Locate and hookup the control wire (hot wire) to the controller station terminal. Station number and color to be given by instructor: Station Number Station Color 2. At the valve strip both control wire (hot wire) and neutral wires (common wire), connect to the valve wires using the dry wire nuts provided in the field box. All Stations on each of the three valves on a manifold will use the same common as shown below. 3. Double check your wiring. OK Problems 34
Field Exercises II. Manual Start (At Controller). 1. Start valve at controller Works Not Working VI. Check Controller Output 1. Remove neutral from controller 2. Manually start your station at controller 3. Check voltage output 4. Record volts measured III. Manual Bleed Valve Recorded Should Read 1. Open manual bleed valve Works Not Working IV. Determine Problem 1. Valve Water Supply 2. Valve problem Ports Stuck Diaphragm Spring 3. Repairs made VII. Check valve solenoid (Good solenoid approximately 50 OHMS) 1. Disconnect leads at solenoid (dry splice wire nuts) 2. Measure solenoid continuity Good Bad VIII. (If time) Check Wiring to valve 1. Install jumper at controller between your station hot lead and the neutral 2. Measure continuity at valve between neutral and hot lead 3. Record reading OHMS 4. Re-try valve with manual bleed Recorded Should Read Works Not Working IX. Re-test V. Manual Start (At Controller). 1. Re-assemble station wiring 2. Test station with controller manual start 1. Start valve at controller Works Bad Works Not Working 35