Siemens LDU11 Series Gas Valve Proving Systems
Product Description
Siemens LDU11 Series Automatic Gas Valve Proving Systems
Siemens LDU11 Series comprises automatic gas valve proving controllers designed to check the tightness of safety shutoff valves in gas burners and gas-fired appliances. By identifying unacceptable leakage before burner operation, the system helps prevent unsafe burner startup.
The LDU11 uses a pressure-based proving method and can operate with one or two suitable pressure switches, depending on the installation. Configurations with or without a vent pipe to atmosphere are possible, provided the applicable Siemens installation requirements are met.
Two-Stage Valve Proving Principle
The LDU11 carries out automatic leakage verification in two pressure-testing stages:
- Test 1 – Upstream Valve: The test space is evacuated, then monitored for an unacceptable pressure increase that would indicate leakage through the upstream gas valve.
- Test 2 – Downstream Valve: The test space is filled with gas and monitored for an unacceptable pressure decrease that would indicate leakage through the downstream valve.
If excessive leakage is detected during either stage, the controller enters safety lockout and prevents burner startup. Fault and program indicators assist in identifying the valve associated with the failure.
Key Features
- Automatic tightness testing of gas safety shutoff valves
- Two-stage pressure proving sequence
- Works with one or two suitable pressure switches
- Inhibits burner startup when unacceptable leakage is detected
- Safety lockout with fault and program indication
- Local reset and electrical remote reset options
- Plug-in construction for convenient controller replacement
- AC 115 V and AC 230 V versions available
- Selected versions conform to DIN EN 1643 requirements
Industrial Applications
- Industrial gas burner installations
- Gas-fired steam and hot-water boilers
- Industrial furnaces
- Gas-fired heating equipment
- Gas valve leakage monitoring and burner safety systems
Installation Guidance: Select the correct LDU11 version according to the power supply, wiring arrangement, pressure switch configuration and burner control requirements. Installation, commissioning and maintenance must be performed by qualified personnel.
Specifications
Siemens LDU11 Series Valve Proving System Technical Specifications
| Manufacturer | Siemens |
|---|---|
| Product Series | LDU11 |
| Equipment Type | Gas Valve Proving System |
| Testing Method | 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 |
| Integrated Fuse | T6.3H250V |
| External Fuse | Max. 10A (Slow) |
| Ingress Protection | IP40 (subject to mounting, excluding terminal base) |
| Electrical Safety Class | Class II |
| Operating Ambient Temperature | -20°C to +60°C |
| Relative Humidity | Less than 95% RH |
| Maximum Installation Altitude | 2,000 m above sea level |
| Approximate Weight | 1,000 g |
| Mounting Orientation | Optional |
| Designed Service Life | 250,000 burner startup cycles |
| Reference Standards | DIN EN 1643, DIN EN 60730-2-5 |
Siemens LDU11 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
*Important: The valve opening times of LDU11.523A17 and LDU11.523A27 do not conform to EN 1643, according to the referenced Siemens datasheet.
Technical Reference: Siemens Datasheet CC1N7696en, dated 16 October 2018. Confirm the exact model, applicable certification and installation requirements before ordering.
Product Specifications
Siemens LDU11 Series Valve Proving System Technical Specifications
| Manufacturer | Siemens |
|---|---|
| Product Series | LDU11 |
| Equipment Type | Gas Valve Proving System |
| Testing Method | 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 |
| Integrated Fuse | T6.3H250V |
| External Fuse | Max. 10A (Slow) |
| Ingress Protection | IP40 (subject to mounting, excluding terminal base) |
| Electrical Safety Class | Class II |
| Operating Ambient Temperature | -20°C to +60°C |
| Relative Humidity | Less than 95% RH |
| Maximum Installation Altitude | 2,000 m above sea level |
| Approximate Weight | 1,000 g |
| Mounting Orientation | Optional |
| Designed Service Life | 250,000 burner startup cycles |
| Reference Standards | DIN EN 1643, DIN EN 60730-2-5 |
Siemens LDU11 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
*Important: The valve opening times of LDU11.523A17 and LDU11.523A27 do not conform to EN 1643, according to the referenced Siemens datasheet.
Technical Reference: Siemens Datasheet CC1N7696en, dated 16 October 2018. Confirm the exact model, applicable certification and installation requirements before ordering.
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