Siemens Valve Proving System LDU11 Series
Siemens Valve Proving System LDU11 Series is an automatic gas valve leakage detection system designed for gas burners and gas-fired appliances. It uses a two-stage pressure proving principle to verify the tightness of automatic gas shutoff valves and prevents burner startup if unacceptable leakage is detected. Features safety lockout, fault indication, and local or remote reset functions. Available in AC 115V and 230V versions, with selected models conforming to EN 1643 requirements.
Product Details
Siemens Valve Proving System LDU11 Series
Siemens Valve Proving System LDU11 Series
Siemens LDU11 Series is an automatic Valve Proving System designed to verify the tightness of gas shutoff valves used in gas burners and gas-fired appliances. It improves combustion system safety by detecting unacceptable valve leakage and preventing burner startup.
The LDU11 operates according to the pressure proving principle and can be used with one or two commercially available pressure switches, depending on the installation configuration. It is suitable for systems with or without a vent pipe to atmosphere, subject to the manufacturer's installation requirements.
Operating Principle
The Siemens LDU11 performs automatic valve proving using a two-stage pressure testing sequence.
- Test 1: Checks the upstream gas valve by evacuating the test space and monitoring for an unacceptable pressure increase.
- Test 2: Checks the downstream gas valve by pressurizing the test space and monitoring for an unacceptable pressure decrease.
If excessive leakage is detected during either test phase, the LDU11 initiates safety lockout and inhibits burner startup. A fault indicator and program indicator help identify the affected valve.
Key Features
- Automatic gas shutoff valve leakage detection
- Two-stage pressure proving operation
- Compatible with one or two pressure switches
- Prevents burner startup when leakage is detected
- Safety lockout and fault indication
- Local and electrical remote reset capability
- Plug-in design for convenient unit replacement
- Available in AC 115V and AC 230V versions
- Selected models conform to DIN EN 1643
Applications
- Industrial gas burner systems
- Gas-fired boiler systems
- Industrial furnaces
- Gas heating systems
- Gas valve safety monitoring systems
Installation Note: Model selection and installation must consider supply voltage, wiring configuration, pressure switches and compatibility with the burner control system. Installation and servicing must be performed by qualified personnel.
Technical Specifications
Siemens LDU11 Series Technical Specifications
| Brand | Siemens |
|---|---|
| Series | LDU11 |
| Product Type | Valve Proving System |
| Operating Principle | Two-Stage Pressure Proving |
| Supply Voltage | AC 115V / AC 230V (model dependent) |
| Voltage Tolerance | -15% / +10% |
| Mains Frequency | 50–60 Hz ±6% |
| Power Consumption During Test | Approx. 3.5 VA |
| Power Consumption During Operation | Approx. 2.5 VA |
| Built-in Fuse | T6.3H250V |
| External Fuse | Max. 10A (Slow) |
| Degree of Protection | IP40 (subject to mounting, excluding terminal base) |
| Safety Class | Class II |
| Operating Temperature | -20°C to +60°C |
| Relative Humidity | Less than 95% RH |
| Installation Altitude | Max. 2,000 m above sea level |
| Weight | Approx. 1,000 g |
| Mounting Position | Optional |
| Designed Lifetime | 250,000 burner startup cycles |
| Reference Standards | DIN EN 1643, DIN EN 60730-2-5 |
Available Models
| Model | Supply Voltage | t3 | t4 |
|---|---|---|---|
| LDU11.323A17 | AC 115V | 2.5 s | 2.5 s |
| LDU11.323A27 | AC 230V | 2.5 s | 2.5 s |
| LDU11.523A17* | AC 115V | 5 s | 5 s |
| LDU11.523A27* | AC 230V | 5 s | 5 s |
t3 = Filling the test space
t4 = Evacuating the test space
*Valve opening times of LDU11.523A17
and LDU11.523A27 do not conform to EN 1643,
as stated in the manufacturer's datasheet.
Reference: Siemens Datasheet CC1N7696en, dated 16 October 2018.
Dimensions
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