Danfoss ECL Comfort 310 Operating Manual page 26

Operating Guide ECL Comfort 310, application A377
2.5.3 Electrical connections, safety thermostats, in general
See also the Installation Guide (delivered with the application key)
for application specific connections.
26 | © Danfoss | 2017.10
When ST is activated by a high temperature, the safety circuit in the
motorized control valve closes the valve immediately.
When ST1 is activated by a high temperature (the TR temperature), the
motorized control valve is closed gradually. At a higher temperature
(the ST temperature), the safety circuit in the motorized control valve
closes the valve immediately.
VI.GU.F6.02