Question 271Steam Plants - Assistant Engineer

The correct answer is C) 15 seconds. Modern boiler automation systems allow a "trial for ignition" period during burner light-off, where the flame safeguard system is temporarily bypassed. This period is limited to 15 seconds by regulation to ensure safety. The 15-second limit allows sufficient time for the burner to ignite while preventing an unsafe condition if the burner fails to light. The other options are incorrect because 5 seconds may not be enough time for the burner to ignite, and 30 seconds would be an excessively long period that could pose a safety risk if the burner does not light within that time.