Honeywell SV2 Series User Manual page 62

SV2 Series Safety Shut-off Valves
Fig. 28: Hi-Gas / Low-Gas Limit Test Screen.
NOTES:
• Upon successful lockout, the valve and likely the burner management system will need to be reset and the burner
restarted to test the second Limit Set Point. The valve will wait for 7 seconds before allowing the burner management
system to power it after a reset, even if there is a call for heat, due to various flame failure response timings.
• When the valve is reset, the Limit Set Points will automatically be reset back to their original settings.
Valve Proving Sequence (VPS) Operation
If programming the valve for VPS functionality via the HMI or PC Tool, whether directed external or internal to the valve, the
Pressure Module must be used.
External VPS is defined as being initiated and operated by an external control, such as a burner management system. SV2
Series valves with Intelligent Feature designations of 6 and 7 can be used with external VPS systems and have a VPS SW contact
closure output for interface with the external control. The VPS SW action is programmed during setup; Pressure to Close or
Pressure to Open. Refer to
When a VPS sequence is initiated by the external control, the SV2 Series valve intelligent models will automatically determine
a VPS sequence is being performed since one valve seat at a time is selectively powered. Accordingly, the valve will initiate
its internal leak detection routine, using the attached Pressure Module to measure the pressure rise or decay in the volume
between the two safety shut-off valve seats. The readings are then compared with the user-selected Leakage Limit threshold
and based on that comparison will toggle the VPS SW output as selected during setup (pressure to close or open). The contact
output action is the same as in a traditional VPS system using a separate pressure switch. Based on the VPS contact output,
the external device performing VPS will determine if the VPS test passed or failed. The valve leakage test results along with the
current valve cycles and hours are stored in the valve memory and can be accessed via the HMI or PC Tools or via Modbus. If the
allowed leakage rate is exceeded, a valve lockout will occur, requiring a valve manual reset.
When using the 7800 SERIES as the burner management system, the VPS function may be performed at any time; before, after,
split or both relative to the call for heat.
For valve models with internal VPS operation the Pressure Module is also used, however, there is no VPS SW contact closure
output since the VPS operation is performed entirely internal to the valve. SV2 Series valves with Intelligent Feature designations
of 8 and 9 include internal VPS functionality and have DMD IN and DMD OUT terminals instead of the VPS SW terminal. The
demand signal is run through the valve so that it knows when there is a call for heat or loss of the demand signal, which is used
to perform the internal VPS before and/or after the demand cycle.
External and internal VPS functionality is programmed via the HMI Tool or PC Tool. During programming, several selections
must be made including the allowed leakage limit, the VPS contact action upon VPS completion (external VPS only), the
connected pipe size and whether or not there is external piping connected between V1 and V2 (such as a pilot take-off). Once
these selections are complete, recommended timing for valve power and test time will be provided for the burner management
Fig. 147 to Fig. 157 for proper valve wiring.
62 32-00029—02