Using a Magnetic Latching principle, the Latch type solenoid has two coils with opposing windings and a permanent magnet.The solenoid has three terminals, for latching (energizing) and De-latching (de- energizing).
On energizing the Latch coil (either by a pulse of power or continuous power), plunger is pulled and latched magnetically.
The Latch solenoid is designed for continuous energization in case the application demands. Loss of power or switching off the Latch coil will not change the valve position. Momentary pulse to the De-latch coil will de-energize the solenoid valve.Optionally a manual override can also manually Latch/manually De-latch the Solenoid valve.
The Latch type Solenoid system has been designed in a manner to facilitate conversion of single solenoid valve to a stay put the device i.e. on power failure to retain last position. However, Manual override feature on single solenoid valve (if installed) cannot be used to de-energize the Solenoid valve manually. These valve have to be de-enegized electrically.