I am going over some boiler startup sequence of operations and there are some terms that I don't quite understand, I am hoping someone could hopefully help me out, I looked online but I can't seem to find anything that makes any sense..High Fire PositionLow Fire PositionLockout InterlockLockout Interlock Inputs
High fire/Low fire positions seem to address a staged burner system with different burner firing settings. Most boilers have a safety system that protects the boil from damage from various events from low water level to loss of the pilot flame. These are all packed in a series of detectors and relays (electrical or electronic) that sense a problem and shut down the boiler. The Lockout interlock inputs would be the sensors. An example would be something like a float switch that detects a low water level. Lockout interlock would be the relay that is tripped by the input and then shuts down the boiler. Some people consider the relay and sensor to be one interlock and do not talk about them as separate items.
