Honeywell SV2 Series User Manual page 93

Fig. 52: OEM Setup Parameters.
Default Pos. 2 (steps)
Refer to Fig. 52. The stepper motor driven Fuel Control Valve (FCV) is set to a start position after each heat demand and
reset of the SV2 Series valve. The first/initial stepper motor start position 2 of the ignition sequence is set with this
parameter.
Based on the ignition amplification and available inlet pressure, the SV2 Series system will learn the right stepper motor
position for starting the appliance, which is recorded as the Learnt Pos. 2 (refer to
motor start position value or adjustment is limited by the user-entered value for Default Pos. 2 in that it can vary up to ±
20% of the entered Default Pos. 2 value or a maximum of ± 10 full steps.
In practice the value that needs to be entered for Default Pos. 2 depends on the start capacity and the available inlet
pressure to the valve. The best way to find a value for the Default Pos. 2 is to have the appliance running at ignition load
(normal operation) at the right CO2 level and normal inlet pressure and record the motor position and use this value for
setting the value of Default Pos. 2 in the OEM Setup screen. Practice values can be somewhere between 100 and 250
steps for the 1.5 in and 2.0 in (DN40 and DN50) valves.
SV2 Series Safety Shut-off Valves
V2F, V2V
SV2 SERIES SAFETY SHUT-OFF VALVES USER MANUAL
93
Fig. 53). The Learnt Pos. 2 stepper