District Heating insulation leak detection wiring

• Surveillance Systems (EN 14419): Applies to the design and installation of the embedded leak detection wiring.

Alarm Wire Design

• Quantity & Size: Two embedded copper wires, each with a cross-sectional area of 1.5 mm².
• Identification: One wire is bare copper, while the other is tinned (coated in a thin layer of tin) to help differentiate them during splicing and testing.
• Placement: Both insulated wires are positioned at an equal distance from the inner steel service pipe inside the foam insulation.

Surveillance Detector Selection

The choice of monitoring equipment depends entirely on the electrical conductivity of the fluid (medium) flowing through the steel pipe:

• High Conductivity (>10 µS/m): You can use either resistance or impedance measuring detectors.
• Low Conductivity (<10 µS/m): You can only use impedance measuring detectors.
• External Leaks: Regardless of the fluid's conductivity, faults caused by groundwater or moisture penetrating from the outside casing can always be detected by the system.