переключатель блокировки защитной автоматики для целей техобслуживания(Maintenance override switches (MOS) are used to override safeguarding initiators to enable maintenance or on-line functional testing. I.e. MOS is used for enabling /disabling (permision to bypasing) shutdown signal from ESD system. Once it enabled you can overide particular loop or swtich or function block. MOS is installed normally on DCS and activating by DCS operator or concerned engineer for allowing maintenance technician to perform calibration or replacement of faulty switches and transmitters. Mixer)
