Controllers

Controllers The controller, also called timer or clock, is the brains of the irrigation system. It is the controller that activates the electric control valves telling them when to open and when to close.. When choosing a controller consider the following: Where is the controller to be located? What is the size and layout of the irrigation system? ( how many zones do you need) What type of programming capabilities do you require? A controller is basically made up of 4 different components. 1. The cabinet - a controller can be either for indoors or outdoors. Indoor controllers will have the transformer on the end of the plug. Outdoor controllers will have the transformer in the cabinet. The cabinet will also usually have a weatherproof seal and often a lock on it. 2. The face plate - the face plate is the front of the controller that contains the dials and displays used to operate the controller. Some controllers use dials to make adjustments and others are digital. 3. The transformer - Controllers run on power under 30 volts AC. Since most of our house voltage is 110-120 volts a transformer is needed to step down the line voltage in the controller. 4. The output board - the output board contains a terminal strip where the valves are wired to the controller.Some models of controller will combine the terminal strip with the face plate, in others the front section of the controller swings open to reveal the terminal strip. Many newer light commercial/ residential controllers have modular terminal strips that allow you to expand the capacity of the controller. The terminal strip may have any or all of the following terminals or stations MV – master valve. “A master valve is normally closed and installed near the supply point of the mainline.” ( Hunter Hydrawise) It is wired to turn the main water supply on and off. It is also called a pump start circuit and can be used to turn a pump on and off. The master valve can be used for vandalism control or for operating more than one controller. It opens when activated. Flow sensors can sometimes be used with a master valve to turn off the system in the case of a leak. VT – valve test. This terminal is live and can be used to test valves without wiring them up. Put one valve wire on the VT terminal and one valve wire on the common terminal. This will test to see if the solenoid is good. C or COM – common . This is used for the common wire going to the valve. There may be one or 2 common terminals. Field wire numbers 1- ? These are used for the field wire or control wire going to the valve. Each valve has its own terminal which will determine when that zone operates. SEN – sensors. This is where the sensors are wired up. Sensors may include flow sensors, rain sensors, rain-freeze sensors, soil moisture sensors, etc In more expensive controllers there is circuitry or protection against electrical surges and lightning. Wiring the valves to the controller The valve wireAll wires used to wire valves to controllers must be rated for direct burial. This will be indicated by a UF or ‘Underground” stamped on the wire. The jacket on UF wire is made of PVC or PE and is waterproof and resistant to chemicals normally found in the soil. The copper wire underneath the jacket can be solid or multistrand. The size of solid wire is referred to as the gauge of the wire. It is designated by the AWG ( American wire gauge number). The larger the gauge number to smaller the wire, the smaller the number the larger the wire. The smallest wire gauge used in irrigation is 18 gauge, the largest gauge is 12 gauge. Wire for irrigation comes in many colours. The standard is to use white wire as the common wire and one colour wire for the power to each valve. Another alternative is to vary the colour of each of the field or power wires. The weakest part of any wire is the splice or connection. When connecting 2 or more wires together make sure and ... Remove the insulating jacketBraid the wires togetherCover the wires with a waterproof connector Use wire strippers to remove the jacket. Make sure you are using the correct hole in the wire stripper so as not to damage the copper conductor. Braid the wires together so that both of the wires are secure. Twisting one wire around the other will just result in failure at the first sign of stress. Cover the wires with a waterproof connector. There are many waterproof connectors on the market. Many on the market contain a silicon gel that waterproofs the connection. The key is to make sure the copper conductor and a bit of the insulating jacket is covered with grease. SMART CONTROLLERS A smart controller will monitor the growing conditions of the plant and automatically adjust the water application accordingly. These controller require accurate programming and should be left to a professional ( not a homeowner) Smart controllers determine the needs of the plant by using the weather to calculate the evapotranspiration rates ( ET) or an SMS ( soil moisture sensor ) to measure the amount of water in the soil. Some smart controllers use both. ET can be retrieved using a sensor in the controller or via satellite. A wired or wireless sensor is set up somewhere in full sun exposure. For satellite sensors there is usually a subscription fee. BASIC CONTROLLER FUNCTIONS Most residential/ light commercial controllers are set so that only one zone can operate at a time. There are 3 or 4 programs and as many as 6 start times per program. Each program is a series of zone run times. An example would be Program A - Zone 1 runs for 10 minutes, Zone 2 runs for 15 minutes, Zone 3 runs for 10 minutes. Note that Zone 2 will not turn on until zone 1 is finished. If you set your program to start at 10:00 am, Zone 1 will come on at 10:00 am and Zone 2 will come on 10 minutes later at 10:10am. Similarly Zone 3 will come on after Zone 2 is finished running so at 10: 25am. This is called stacked programming. At the beginning of the season. Make sure all the wiring is tight. Plug in the controller and change the battery. Set the correct time and date on the controller. Program the zones according to the scheduled run times. https://support.hydrawise.com/hc/en-us/articles/360024346234-Master-Valve-Wiring-and-Software- https://www.irrigationtutorials.com/faq/master-valve.htm http://www.wplawinc.com/FAQRetrieve.aspx?ID=49005 Von Bernuth, Robert D.; Irrigation System Installation and Maintenance 2nd Edition; September 2013; www.irrigation.orgLandscape