Honeywell SV2 Series User Manual page 108

SV2 Series Safety Shut-off Valves
Fig. 63: Ramped startup with control startup delay and leaner mixture.
NOTE: Changes to the ignition behavior need to be verified by selecting Verify Safety Parameters at the bottom of
the screen before burner operation.
Select begin, check the modified parameters, press Yes on the screen and press the valve Reset button, following
instructions on the HMI/PC Tool screen.
Record Ign. Air Level parameter
The SV2 Series valve will check the combustion air level during the ignition phase. To do so, the ignition air level needs
to be recorded under normal conditions by checking this box. After modifying the ignition settings that influence the air
volume during ignition, like fan speed and flue length / air filters, the ignition air level needs to be recorded / corrected
for this new situation. This prevents the system from checking the ignition airflow against an incorrect value.
During the first burner start when the air level is recorded, this check box is automatically unchecked.
NOTE: Checking and unchecking the Record Ign. Air Level check box will erase the recorded ignition air levels and
causes a lockout of the SV2 Series valve when installer mode is exited.
Stepper Motor / Fuel Control Valve Full Stroke Check
Every time the two SSOVs close, the full stroke of the fuel valve is checked; the stepper motor is driven to its maximum
open position then to its fully closed position while the number of steps in between are counted. Afterwards it is
driven to its ignition position (represented by the Learnt Pos. 2 and the Ramp Offset parameter setting). During this
time, the first SSOV seat is closed. The test takes approximately 30 seconds to complete. A call for heat before the full
stroke check is completed could cause valve or burner management control lockouts and/or poor ignitions until the
settings are stabilized (refer to the Learnt Pos. 2 for details).
NOTE: If there is a loss of main flame, some controls may try to re-light immediately. In this case, program the
burner management control to perform a combined post-purge and pre-purge timing to equal a minimum of 30
seconds to give the SV2 Series valve time to reset itself to the proper ignition position and prevent unnecessary
faults or ignition issues.
108 32-00029—02