UPL Boiler DCS Operator Interview Questions and Answers

Starters are used to control the starting and stopping of motors. Types include DOL, star-delta, soft starters, and VFDs.

• Direct-On-Line (DOL) starters provide full voltage to the motor at start-up

• Star-Delta starters reduce the voltage during start-up to reduce inrush current

• Soft starters gradually increase the voltage to the motor to reduce inrush current and mechanical stress

• Variable Frequency Drives (VFDs) control th...read more

The 3 tier breaker interlock scheme is used to ensure safe and efficient power distribution from different sources.

• The scheme involves three levels of protection to prevent power overload and equipment damage.

• The first tier involves interlocking the main breaker with the emergency stop button to quickly shut off power in case of an emergency.

• The second tier involves interlocking the main breaker with the VFD and starte...read more

Sheffy valve setting is the pressure at which the safety valve of a boiler is set to open and release excess steam.

• Sheffy valve setting is crucial for maintaining safe pressure levels in a boiler.

• It is typically set slightly above the maximum allowable working pressure of the boiler.

• The setting is determined based on the design and capacity of the boiler.

• Regular maintenance and testing of the safety valve is important ...read more