A lockout switch will energize after __ to __ seconds.

A lockout switch will energize after __ to __ seconds.

a. 5 to 10
b. 15 to 30
c. 10 to 15
d. 20 to 40
e. 15 to 25






Answer: B

On-off controls are common on?

On-off controls are common on?

a. firetube boilers
b. watertube boilers
c. small package boilers
d. large package boilers
e. all of the above

Answer: C

If the damper motor does not operate on a boiler which one would NOT be the possible cause?

If the damper motor does not operate on a boiler which one would NOT be the possible cause?

a. Damper positioning switch in wrong position.
b. Linkage loose or jammed.
c. The lock-out switch has tripped.
d. Motor does not drive to "open" or "close" during prepurge or close on burner shutdown.
e. Motor does not operate on demand.

Answer: C

If the burner stays on low fire on a boiler which one would NOT be the possible cause?

If the burner stays on low fire on a boiler which one would NOT be the possible cause?

a. Boiler pressure above high-low fire control setting.
b. Damper positioning switch in wrong
c. Inoperative damper motor.
d. Flame detector weak or defective.
e. Defective high-low fire or modulating control.





Answer: D