SIEMENS Burner Control Series LDU11
- Holding torque: 0.8, 3 Nm. Easy-to-adjust end and auxiliary switches for setting the switching points
- Running time: 4.5 30 s , Internal and external position indication
- Direction of rotation: counter clockwise. Superior finish with Maintenance-free gear train, which can be disengaged
- Screw terminals for the electrical connections
- Impact-proof and heat-resistant plastic housing
The LDU11… is designed for automatic gas valve proving (leakage test) based on the pressure proving principle. It is for use on gas-fired combustion plant with or without vent pipe to atmosphere. In the case of plants with no vent pipe where EN standards apply, the notes given in «Connection examples without vent pipe to atmosphere» must be observed.
Used in connection with 1 or 2 commercially available pressure switches, valve proving is automatically initiated with every burner startup, either
– prior to burner startup
– during the prepurge time if it lasts a minimum of 60 seconds
– immediately after a controlled shutdown, or
– on completion of the burner control’s control sequence, e.g. at the end of the postpurge time
The valve proving test is based on the 2-stage pressure proving principle:
1. The valve on the mains side is tested by evacuating the test space and by monitoring the atmospheric pressure in it.
2. The valve on the burner side is checked by pressurizing the test space and by monitoring the gas pressure.