Honeywell SV2 Series User Manual page 60

SV2 Series Safety Shut-off Valves
STRAINER
MAIN FUEL TRAIN
MSOV MSOV
PILOT FUEL TRAIN
(Optional)
Fig. 26: Pressure Module Operational Diagram.
The statements below are relative to EN1854 2010: Pressure sensing devices for gas burners and gas burning appliances.
EN1854 also refers to EN60730-2-6.
For high gas pressure and low gas pressure, the DUT (device under test) combines pressure reading with the knowledge of
the valve status (ON or OFF) and therefore only evaluates HGP/LGP when the sensors are exposed to the relevant pressure;
i.e. when both valves are open and non-zero flow is established. Pressure events can only be detected after valves are open; in
other words, LGP cannot prevent the start of the ignition sequence as in a traditional system. However, the reaction time of LGP
detection is less than 3 seconds, causing the DUT to enter non-volatile lockout. Moreover, if a LGP event appears during the
burner cycle, the operation of the SV2 Series valve and Pressure Module is analogous to today's mechanical pressure switch
based systems.
When the Pressure Module is used with the SV2 Series valves, VPS and HGP/LGP provides Class B control according to EN1854.
When the Pressure Module is used with the SV2 Series valves, the response time to a HGP/LGP event is 2.7 seconds maximum.
When the Pressure Module is used with the SV2 Series valves, the internal fault reaction time for HGP/LGP is 2 seconds.
The HMI or PC Tool is used to program all available functions using the Pressure Module via an embedded set-up wizard.
Programming includes the low and high gas pressure lockout type, limit settings, VPS leakage limit along with any associated
connected pipe volume and VPS contact action. Additionally, the HMI and PC Tools have built-in testing mechanisms for the
limit settings so they can be verified for installation purposes. For detailed step-by-step programming setup instructions,
consult the HMI / PC Tool user manual, 32-00031.
Low Gas Pressure and High Gas Pressure Operation
When using the Pressure Module for the gas pressure limit functions, both the low and high gas functions MUST be used
together.
Note that the SV2 Series valves have unique interlock wiring requirements in that the Interlock wiring is run through all valve
models for the solenoid power saving feature. Additionally, since the low gas limit and high gas limit functions are contained
in the Pressure Module and are part of the Interlock string, if activated, there is an Interlock dry contact input / output in the
valve electronics for the flame safeguard control ILK string. Refer to the SV2 Series Wiring paragraph in the WIRING OVERVIEW
section of this manual for details as well as
Since the SV2 Series valves cannot sense a low gas pressure condition prior to opening, it will actively sense and react to the
condition once both valve seats are opened. The response time upon sensing the condition is 2.7 seconds after which the valve
seats will be closed and the valve will annunciate the fault condition both on the valve face via the LGP LED and the HMI / PC
Tool, if connected.
SSOV/ SSOV/
POC 1 POC 2
STRAINER
LGP HGP
PRESSURE
REGULATOR
NOVV
MSOV PRESSURE
REGULATOR
Fig. 147 to
MSOV
MODULATING
ACTUATOR/
VALVE
PILOT
VALVE
MCR37161
Fig. 157 for proper valve wiring.
60 32-00029—02