Cleveland SteamCraft 10 Service Manual page 208

204 SteamCraft 10 Service Manual, Chapter 8
? Make sure pilot lights smoothly when gas reaches the pilot
burner.
?Make sure main burner lights smoothly without flashback.
?Make sure burner operates smoothly without floatin g,
lifting, or flame rollout to the furnace vestibule or heat
buildup in the vestibule.
?If gas line has been disturbed, complete gas leak test.
OPERATION
Module operation can be conveniently divided
into two phases for S8600, S8610 and three for S8660,
S8670. The phases are
•
Prepurge (S8660, S8670 only)
•
Trial for ignition (all models)
•
Main burner operation (all models)
Figs. 11 and 12 summarize the normal operating
sequences of the modules.
Printed 3/93
Models 24-CGA-10 and 24-CEA-10
GAS LEAK TEST: Paint gas control gasket edges and all
pipe connections downstream of gas control, including pilot
tubing connections, with rich soap and water solution.
Bubbles indicate gas leaks. Tighten joints and screws or
replace component to stop gas leak. Recheck with soap and
water.
?Turn thermostat or controller below room temperature.
Make sure main burner and pilot flames go out.
PREPURGE (S8660, S8670 ONLY)
When the S8660 is used in a fan-assisted combustion
system, the combustion air blower starts on a call for
heat. On proof of airflow, the air proving switch closes
and energizes the S8660, S8670. When the module is
used in an atmospheric system the call for heat energizes
the module.
In either case, the module first initiates a 45 sec.
Delay to allow system prepurge. After prepurge, the
module starts the pilot ignition sequence.
12
Cleveland Range. Inc.