Question 471Steam Plants - Assistant Engineer

The correct answer is A) opens the burner circuit upon sensing a flame failure. A photoelectric cell in an automatically fired auxiliary boiler burner management system is designed to detect the presence of a flame. If the photoelectric cell senses a flame failure, it will open the burner circuit to shut off the fuel supply and prevent a potentially hazardous situation. The other options are incorrect because: B) detecting flame failure by monitoring radiant heat is not the primary function of a photoelectric cell, C) the photoelectric cell does not require mechanical linkage to secure the fuel supply, and D) the photoelectric cell does not need to be bypassed at low firing rates as it continues to monitor the flame regardless of the burner's operating level.