The WA4 mechanical latch for contactors of type AF09 ... AF96 and auxiliary contactors of type NF ensures that the contactor or auxiliary contactor remains closed even in the event of a lack of voltage or a power failure.
Standard contactors can easily be converted into compact latched contactors.
The WA4 block contains a mechanical latch with unlatching by electromagnetic pulse (AC or DC pulse) or manually.
The latch keeps the closed contactor in the closed state after closing if the supply voltage at the contactor coil connection terminals fails.
The contactor is opened:

• Electrically by a pulse (AC or DC pulse) on the coil of the WA4 block (the coil is not designed for continuous control)
• Manually by pressing the button on the front of the WA4 block.
The WA4 block is snapped onto the front of the 1-level contactor and occupies two slots in the middle position.
Additional auxiliary contacts can be attached to the side of the contactor.