750-368
CBEX Elite 100-1200 HP
4-1
CHAPTER 4 Sequence of Operation
4.1 — Overview
This chapter outlines the electrical sequencing of various controls through the pre-purge, ignition, run, and shut-
down cycles of the burner.
The burner and control system are in starting position when the following conditions exist:
• Boiler water is up to the correct level, closing the low-water cutoff switch, and the auxiliary low water cutoff,
if applied.
• The low-water light (panel) is off.
• The operating limit pressure control (steam boiler) or the operating limit temperature control (hot water boiler)
and high limit pressure or temperature control switches are closed.
• All other limit circuit switches are closed.
• All entrance panel switches are closed and power is present at the line terminals corresponding to:
a. Blower motor starter.
b. Air compressor motor starter (if provided).
c. Oil pump motor starter (if provided).
• The load demand light is on.
Chapters 5 and 6 contain operating instructions and specific information on setting and adjusting the controls.
NOTE: The intent of this section is to provide a general overview of a typical boiler operating sequence. Specific con-
trol circuit components/interlocks, and control system hardware and programming may vary depending on installa-
tion. Please refer to the wiring diagram prepared by Cleaver-Brooks for your specific installation.