Honeywell S8910U3000 Instrucciones Para La Instalación página 15

Purge/Prepurge
When the S8910U is used in a fan-assisted combustion
system, the combustion air blower starts on a call for heat from
the thermostat. On proof of airflow, the air proving switch
closes and energizes the S8910U. When the S8910U is used
in an atmospheric system, the call for heat energizes the
module.
SYSTEM WILL
NOT START
CALL FOR HEAT (24V
TERMINAL POWERED)
INITIALIZATION CHECKS
FLAME
SIMULATING
PREPURGE (32 SEC)
FAILURE
NO FLAME
SIMULATING
FAILURE
IGNITER WARMS UP (7
(12), 17 (27), 34 OR 45 SEC)
GAS CONTROL OPENS
FOR TIMED TRIAL
FOR IGNITION.
IGNITER OFF;
FLAME SENSING BEGINS.
FLAME
PRESENT
GAS CONTROL STAYS
OPEN (MAIN BURNER
RUNS).
CALL FOR HEAT
IS SATISFIED.
GAS CONTROL CLOSES
(MAIN BURNER OFF).
Fig. 6. S8910U normal operating sequence.
In either case, the S8910U first initiates a 32-second delay to
allow system prepurge.
Igniter Warmup
After prepurge, the S8910U energizes the igniter to start the
igniter warmup. The module energizes the hot surface igniter
for the selected warmup period; the gas control is closed
during this period.
WELDED
DEVICE LOCKED
RELAYS
(REPLACE CONTROL)
DETECTED
INTERPURGE
(64 SEC)
NO
FLAME
THREE
TRIALS
GAS
FLAME
CONTROL
FAILURE
CLOSES
ONE
TRIAL
LOCKOUT OCCURS.
SYSTEM MUST BE
RESET.
15
S8910U3000
LESS
THAN
THREE
HOW MANY IGNITION
TRIALS COMPLETED
THIS CALL FOR HEAT?
THREE
M35558
34-00008EFS—01