Electric Heating Cable Guide

  Electric tracing cables are widely used for pipeline freeze protection and heat preservation of easy-to-crystallize media. Many engineers and purchasers only focus on length and price while ignoring working condition matching, which may lead to insufficient heating, cable aging, tripping and even potential safety hazards in later operation. There are three mainstream types of electric tracing cables: Self-regulating tracing cable: It adopts PTC material for automatic temperature limitation and can be cut on site for easy installation. Low-temperature versions are suitable for freeze protection of fire-fighting and water supply pipelines. Medium-temperature shielded & explosion-proof versions are applied to pipelines carrying easy-to-crystallize media such as urea and brine. Note: The marked power is the starting power at low temperature; the power will drop naturally as temperature rises. Constant-power tracing cable: It delivers stable heat output with higher temperature resistance, ideal for long-distance process pipelines. It has no overheat self-protection, so a thermostat is mandatory and overlapping laying is prohibited. MI mineral insulated tracing cable: It features high temperature resistance and superior explosion-proof performance. It is adopted for high-temperature and high-risk working conditions with relatively high cost.   Typical Application Case In a urea transfer pipeline project of a chemical park, low-temperature self-regulating tracing cables were improperly used at the beginning. Coupled with irregular overlapping installation, pipeline blockage caused by crystallization and rapid cable aging frequently occurred in winter. After renovation, medium-temperature explosion-proof self-regulating tracing cables were selected. Extra tracing length was arranged on heat dissipation points including valves and flanges. Supporting thermostats and waterproof insulation layers were equipped. The pipeline temperature remained stable in consecutive winters without crystallization and blockage.   Procurement & Acceptance Key Points Confirm the medium type, pipe specification, minimum ambient temperature, explosion-proof requirement and target maintenance temperature in advance. Verify explosion-proof certificates for explosion-prone areas and ensure reliable grounding of the shielding layer. Use original special sealing kits for joints and terminals of self-regulating cables; tape wrapping alone is not allowed. Constant-power tracing cables must be equipped with temperature control systems. Insulation resistance tests shall be carried out after goods arrival and laying. The cables can be put into use only when the insulation test passes.   Common Faults, Troubleshooting & Solutions Cut off the power supply before troubleshooting. Follow explosion-proof operation specifications for maintenance in hazardous areas.   1. No heat output at all Causes: Power failure, circuit breaker tripping, water ingress and short circuit in junction boxes, cable breakage or loose connections. Check: Verify power supply and protective switches in the distribution box. Test insulation section by section with a megger after power-off and check junction boxes for water corrosion. Solution: Re-crimp and seal loose connections; replace the broken cable section directly.   2. Insufficient heating, failure to reach target temperature Causes: Underpowered selection, damaged and waterlogged insulation, insufficient tracing length, no extra tracing on heat dissipation points such as valves and flanges, or power attenuation of aged self-regulating cables. Check: Inspect insulation for damage and moisture, and verify cable specification and laying layout. Solution: Repair insulation and waterproof layers; add extra tracing cables at weak heat preservation points; replace severely aged tracing cables.   3. Frequent tripping after power-on Causes: Damaged outer sheath leading to electric leakage, internal short circuit, or overload exceeding the rated current of the circuit breaker. Check: Test the circuit breaker separately and locate the leakage section via sectional insulation tests. Reminder: Do not replace with a larger circuit breaker blindly, as it will lose leakage protection and bring fire risks.   4. Local overheating and yellowed, aged outer sheath Causes: Overlapped laying of constant-power cables, failed thermostat or temperature sensor. Check: Examine laying method and check whether the temperature probe falls off or the thermostat malfunctions. Solution: Separate overlapped cables; repair or replace temperature control accessories.   5. Uneven heating (hot in one section, cold in another) Mostly seen on self-regulating cables: local damage from extrusion, broken inner core or poor contact at joints. Solution: Locate the faulty section by sectional tests, cut off the damaged part and re-connect and seal with special kits.   Daily Operation & Maintenance Suggestions Carry out insulation tests and thermostat calibration before every winter. Regularly inspect insulation layers and repair waterproof damages timely. Check shielding grounding regularly for explosion-proof areas. Avoid mixing tracing cables of different models or power ratings during maintenance and replacement. There is no universal tracing cable. The core of selection is to match the heat loss and site working conditions. If you provide pipeline parameters and field conditions, we can offer customized heat tracing solutions.