YORK YK — Safety stop

The panel displays Safety stop on the OptiView Touchscreen Control Center. The manual lists this wording among the safety fault messages of the chiller, and it is the only form in which the message is printed — there are no variants of the display text.

This message is set when the panel safety stop hardware push button is pressed, which removes the input from the I/O board terminal TB3-28 for more than 500 ms continuously; the local command is also set to stop. The Safety stop switch is read as a 120 V digital input on I/O board 1743 at terminal TB3-28. Pressing the red SAFETY STOP button on the control panel cabinet shuts the chiller down immediately, and the chiller does not run under any condition while the button is pressed. The manual notes that this position is required for many maintenance tasks to be completed, and that the safety stop is not intended for normal shutdown of the chiller.

• The red SAFETY STOP push button on the control panel cabinet was pressed — the manual permits this to immediately shut down the chiller if needed, such as in an emergency situation.
• The button is still in its pressed position, for example because it was set there for a maintenance task that requires this position and has not yet been released.

1. Look at the red SAFETY STOP button on the side of the control panel cabinet and confirm whether it is pressed.
2. Rotate the SAFETY STOP button clockwise to release the stop condition.
3. Go to the System Details Screen and locate the listed Safety stop event.

• Safety Stop — the control center displays the factory programmed setting for the safety stop control, either enabled or disabled.

Release the button first: The SAFETY STOP button must be rotated clockwise to release the stop condition. Then clear the event — The chiller can be started when the push button is released, and the Clear button is pressed next to the listed event on the Systems Details Screen. While the button remains pressed, the chiller does not run under any condition. For routine stops, use the normal Stop control: the manual directs you to always use it unless an emergency situation exists, in which case the Safety Stop button may be used.