Swimming Pool Timers are the most basic of pump controls. They are often secured to the wall outside near your pool equipment, usually in a metal weatherproof enclosure which work best in all climates. Automated timers are used to control your in ground pool or cleaner pumps. Timers are also used in above ground pool applications. Aplus Pool Parts offers Intermatic timers as this is the brand we'll be talking about, however some of the basic principles apply to all brands.
Mechanical or Digital Timer
Dial type mechanical timers use trippers to set the on/off times. Since they were the most popular years ago, still many of these timers are in use today, mechanical timers are being replaced by digital timers because they can be programmed and include some built in appliactions from the manufacturer.
Aplus Pool Parts recommends selecting the Digital over the Mechanical because the manufactures are phasing out mechanical types. The new Digital Timers are more available and can easly replace the mechanical timer mechanisms. The voltage used by your equipment can be either 120v to 240v so specify the right voltage for your application, some timers can be used for either voltages.
Freeze Protect Timer
You can add a freeze protect mechanisms to insure that the pool pump and heater turn on when temperatures drop below or near 32 degrees. The freeze protect will aide your pool and spa equipment against freeze damage. Freeze protection can also help to get your system going earlier in the season when the days are warm enough to swim but the nights are cold.
A/G Pool & Spa Timers
Timers for portable or above ground pools or spas are specially designated to control the pump system of these types. Timers for these two types usually come with a standard 3-prong twist lock plug. Intermatic Timers can also be used for other applications outdoor of indoors. Inertmatic timers are recommended for use with 1hp pumps only. Hayward makes a microprocessor timer capable of supporting a 1.5hp pump.