Stop Category 1
According to IEC 60204-1 this is a controlled stop: power is kept available to the machine actuators until the machine stops, and power is removed once motion has ended. Because it reduces load swing and uncontrolled dropping, it is frequently preferred in lifting applications.
In Category 1 the stop is in two stages. First the driver or braking circuit brings the speed to zero; then a time relay or standstill monitoring circuit removes power. For this reason the architecture always needs two elements: the unit that performs the controlled deceleration and the independent layer that guarantees power removal.
- The deceleration time is determined by risk assessment; the delay relay is set according to that time.
- Power removal is not left dependent on the correct operation of the decelerating unit; a separate contactor or safety relay is used.
- Compared with Category 0, mechanical wear and load swing are noticeably reduced.
An emergency stop can only be category 0 or 1; which one is chosen depends on the character of the load and the motion. A radio remote control set with relay contact outputs does not produce category 1 on its own; the controlled deceleration is provided by the driver in the panel, a braking resistor or a two-speed stage, while the remote control set only issues the command.
The context in which this term is used: Wireless remote control installation: pairing, relays, safety