A kill switch, also known as an emergency stop or e-stop, is a safety mechanism used to shut off a device in an emergency situation in which it cannot be shut down in the usual manner. Unlike a normal shut-down switch/procedure, which shuts down all systems in an orderly fashion and turns the machine off without damaging it, a kill switch is designed and configured to a) completely and as quickly as possible abort the operation, even if this damages equipment and b) be operable in a manner that is quick, simple (so that even a panicking operator with impaired executive function can activate it), and, usually, c) be obvious even to an untrained operator or a bystander. Many kill switches feature a removable barrier or other protection against accidental activation (e.g., a plastic cover that must be lifted or glass that must be broken).

Kill switches are featured especially often as part of mechanisms whose normal operation or foreseeable misuse may cause injury or death; designers who include such switches consider damage to or destruction of the mechanism to be an acceptable cost of preventing that injury or death.


E-Stops on Industrial Machines

There are 3 standards that define the requirements for emergency stops categories, and all 3 are very simmilar:

  • ISO13857
  • IEC60204-1
  • NFPA97




Minimun Requirements

All machines MUST have a Category 0 stop. It can be achieved by switching off (power disconnect), by phisically "pulling the plug" from the power supply socket, through a E-Stop circuit, etc. This means that not all machines require a E-Stop as long as the Category 0 stop can be achieved by other means.


AGO Winches

All AGO Environmental Winches have a Category 0 stop available and we offer a Category 2 Kill Switch as an option (on the smaller winches) or as standard (on the bigger ones).

Our decision of using a Category 2 Kill Switch is based on the possible damage that a Category 0 stop can produce on the winch. A sudden removal of power will activate the electromechanical brake instantaneusly. If the winch is moving a load at that moment this sudden stop could break the line or damage the winch structure. The Category 2 stop will take the winch to a controlled stop.

However, we offer the option of upgrading the Kill Switch to Category 0 or 1 if the customer or application requires it with an additiona cost.


For more information:

Emergency Stop Categories