3dc Cable for District Cooling insulation leak detection
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Technical Specifications of the 3dc Cable
- Conductor Count: 3 individual conductors embedded in a single cable.
- Conductor Profile: 0.75 mm² stranded copper wire (not solid wire).
- Insulation: Fully insulated throughout, including all joint connections.
Layout and Wire Configuration
- Outer Wires: 2 alarm conductors marked in red, placed at the outermost positions.
- Center Wire: 1 reference conductor marked in black, placed exactly in the middle.
[Red Wire] ------- [Black Wire] ------- [Red Wire]
(Alarm Wire) (Reference Wire) (Alarm Wire)
Key Operating Principles
- Carrier Pipe Flexibility: Works on traditional steel carrier pipes, plastic carrier pipes, and any other electrically non-conductive pipe materials.
- Reference Simulation: The center black wire functions as the reference conductor, completely replacing the need for a conductive steel service pipe to complete the measuring circuit.
- Measurement Type: Relies exclusively on impedance measuring to monitor the pipe network. Resistance-only methods cannot be used.
- Circuit Path: The monitoring system measures the electrical impedance between the two outermost red alarm wires and the center black reference conductor.
Managing Condensation & Continuous Operation
- The Challenge: District Cooling lines inherently suffer from condensation and moisture accumulation inside the insulation. This is highly problematic during repairs or new connections when hot ambient air meets the cold media pipe.
- The Solution: By utilizing fully insulated 3dc cables, the network does not need to be shut down when moisture enters the insulation.
- Reference Curves: The monitoring system establishes new baseline "reference curves" that adapt to and account for this built-in moisture, allowing the network to remain operational without triggering false alarms
