| Automatic sprinkler system controllers are | | | | have become very popular. Although they are |
| programmed to go on and off on a certain day | | | | more expensive than the wired devices, the ease |
| and at a certain time. The controller does not | | | | of installation and increased placement options |
| know if it is sunny and dry outside or raining. For | | | | offset the cost. Most wireless units come with |
| this reason every lawn sprinkler system should | | | | by-pass switches built into the device. Some digital |
| have a rain sensor. | | | | controllers also offer by-pass options for both |
| The sensor determines whether or not enough | | | | wired devices and wireless rain sensors. |
| rainfall has occurred in order to skip an irrigation | | | | No matter the type of rain sensor type that you |
| cycle. There are three basic types of rain sensors. | | | | choose, all rain sensors offer many advantages |
| They all serve the same purpose: keeping your | | | | over not adding this detector to your automatic |
| system from over-watering the turf or your | | | | sprinkler system. Some of the immediate and long |
| garden. How does it do that? The electrical | | | | term benefits include:o Saves Money. Whether |
| connection between the sensor and your sprinkler | | | | you pay for city water or spend electricity |
| system controller is interrupted when a certain | | | | running a pump, the money you save over time |
| amount of rain triggers the device. The sensor | | | | will more than pay for the rain sensor.o Extends |
| breaks the electrical connection so that electricity | | | | Sprinkler System Life Span. Irrigation systems are |
| cannot flow to either the sprinkler valves or to a | | | | made up of moving parts. If the system parts |
| pump start (if your system is on a well without a | | | | are utilized less frequently (during the rainy |
| pressure tank). | | | | season), they last longer.o Protects Water |
| One type breaks the connection by weighing the | | | | Resources. By limiting the over use of your |
| water in a rainfall collection cup. The problem with | | | | sprinkler system, rain sensors reduce excess |
| this type is that leaves, sticks, or the occasional | | | | water run-off that carries fertilizers and pest |
| lizard will find its way into the collection cup and | | | | control chemicals into our shared water supply.o |
| therefore turning off the system. | | | | Conserves Water. Less water is wasted when |
| The next type uses electrodes to determine how | | | | less supplemental water is needed for your turf |
| much water is in the collection cup. This kind of | | | | and in your garden. |
| rain sensor device also has a system problem of | | | | How much money can you save with a rain |
| collecting things other than rainfall in the collection | | | | sensor device? |
| cup. | | | | It will vary based on your water source (city, |
| The most common type of rain sensor used by | | | | re-claim, or well) and where you live (water costs, |
| professionals is the expansion disk device. This | | | | electrical rate, climate). Here is one example that |
| kind of sensor does not use a collection cup; | | | | demonstrates the benefits listed above: |
| instead rainfall causes cork disks to expand. This | | | | Seminole County, Florida. |
| device uses a pressure switch to break the | | | | System Description:o Designed to irrigate a |
| electrical connection. These can be adjusted in | | | | quarter acre of grass and programmed to apply |
| increments of ¼" to the desired rain fall | | | | ½" of water every time the system runs.o |
| setting. This adjustment is usually set to turn off | | | | This schedule would equal 6,788 gallons per |
| the sprinklers after ½" of rain has fallen. | | | | irrigation cycle.o This system (on City Water) |
| The most important aspect of installing a rain | | | | pays $2.30 per thousand gallons.o Every time the |
| sensor is where to place it. It should be installed in | | | | rains sensor interrupts a sprinkler cycle, you would |
| an area that is unobstructed by trees, roof over | | | | save $15.61 |
| hangs, or anything else that might block rain from | | | | According to a recent study in Florida, the use of |
| getting to the sensor. If it is a wired sensor, | | | | a rain sensor device averaged a 45% savings in |
| placement is generally near the sprinkler controller. | | | | water for single-family residential water usage. |
| The wires should be connected inside the | | | | The next time you see a sprinkler system running |
| controller's valve wiring panel. This allows for | | | | in the rain, you now know it doesn't have to be |
| easier electrical trouble-shooting of the system as | | | | that way. Rain sensors are affordable solutions to |
| the sensor can be easily disconnected. | | | | conserving our water, protecting our water |
| In the last few years, FM wireless rain sensors | | | | resources, and saving you money. |