There are a many types of sprinkler timers, each designed for different applications. The main two categories are electromechanical and solid-state (digital). Within those types, there are timers for drip irrigation, battery-operated timers, PC timers, solar-powered timers, and hose-end timers. Most of these types of sprinkler timers are fairly self-explanatory, so this article will only cover timers that can use additional clarification.
Electromechanical or Solid-State (Digital)
Electromechanical timers use both electric clock and motor, wheels, dials, gears, and pins, and are therefore less prone to malfunction due to power fluctuations. Electromechanical timers are very simple, which makes them easy to operate, but limits the amount of programming features available.
Sprinkler timers will have different features, depending on the design and manufacturer, but there are some key features you should consider when shopping for a timer.
Clock and Calander Settings –
these settings allow you to program watering times, control cycles, and make seasonal adjustments.
Manual Start and Manual Station Operation –this allows you to operate a station or start an automatic cycle without affecting the programmed schedule. This is helpful during maintenance, as it allows you to check for leaks, misaligned or broken sprinkler heads, and adjust spray arcs and replace nozzles.
Master Switch – this overrides the automatic functions of the stations.
Master Valve Control – the valve will prevent water flow to the system in the case of water problems or system failure.
Station Omission – this allows you to select which stations will and will not run.
Pump Start Lead – this feature turns on a pump start relay when a station activates, combining irrigation and pump control. A pump start relay is necessary for irrigation systems which run off pump water. Never connect a pump directly to a sprinkler timer, as it will damage the timer.
Rain Sensor – these sensors will shut off your sprinkler system when rain is detected, saving you water and money, and preventing your plants from being over-watered. Most rain sensors have a bypass switch which allows you to override the sensor.
Battery Backup – if the power is disrupted or goes out, the timer reverts to battery power. The battery backup typically only allows the timer to maintain the time, date, and watering schedule, although some controllers allow the user to program the controller while on battery backup. NOTE: Watering will not occur without AC power. The battery only stores the scheduling until AC power is restored or the battery dies.
Non-Volatile Memory – this allows the timer to maintain program data (such as time, date, and watering schedules) without battery or AC power. Note: watering will not run on non-volatile memory.
Delay – the delay feature allows time for valves operating in one zone to close fully before opening valves in another zone.