Wire and Cable Tracking Resistance Tester

High Voltage Tracking Resistance Tester and Tracking Resistance Tester CTI represent two types of failure phenomena exhibited by insulating materials under different voltage environments. The core differences lie in electric field strength, tracking formation mechanism, and material failure mode. Below is a detailed comparison and selection advice:

I. High Voltage Tracking Resistance Tester vs Tracking Resistance Tester CTI Differences

| Characteristic | High Voltage Tracking | Low Voltage Tracking |

| Voltage Range | Typically >1 kV (e.g., power grid equipment, high-voltage cables) | Typically <1 kV (e.g., household appliances, low-voltage electronic devices) |

| Electric Field Strength | High electric field causes intense partial discharge and electrical erosion | Weaker electric field, relies on contaminants or humidity to initiate tracking |

| Tracking Mechanism | Direct breakdown of material or carbonization path due to strong electric field | Combined action of contaminants (e.g., salt mist, dust) and moisture |

| Failure Speed | Faster (may form conductive pathways instantly) | Slower (requires long-term accumulation of contaminants) |

| Material Failure Manifestation | Deep carbonization, ablation, possible arc damage | Surface conductive pathways, localized carbonization or oxidation |

| Testing Standards | IEC 60587 (Tracking Resistance Test under High Voltage) | IEC 60112 (Conventional CTI Test, Voltage ≤600 V) |

II. Key Factors for Selecting Insulating Materials

1. Voltage Level

- High-voltage scenarios (e.g., power transmission and distribution equipment): Choose materials with high CTI (Comparative Tracking Index ≥600 V), such as cross-linked polyethylene (XLPE), epoxy resin, or silicone rubber.

- Low-voltage scenarios (e.g., PCB substrates): Materials with CTI ≥175 V can be used, such as FR-4 epoxy boards or polyamide (PA), but stability in long-term contaminated environments must be considered.

2. Environmental Conditions

Contamination Level: In high-voltage environments with conductive dust, materials must possess resistance to electrical erosion; in low-voltage humid environments, material hydrophobicity and hydrolysis resistance are critical.

- Temperature: High-temperature environments (e.g., motor windings) require heat-resistant materials (e.g., polyimide film).

3. Material Characteristics

- High-voltage priority: High dielectric strength, arc resistance (e.g., PTFE or ceramic-filled plastics).

- Low-voltage priority: Surface hydrophobicity, ease of cleaning (e.g., silicone coatings).

4. Cost and Processing

- High-voltage materials (e.g., specialty engineering plastics like PEEK) are costly, requiring a balance between performance needs; low-voltage scenarios can use economical materials (e.g., PBT or PET).

III. Typical Application Scenarios and Material Recommendations

- High-voltage Scenarios

- Examples: High-voltage insulators, transformer bushings

- Materials: Silicone rubber composite insulators (strong weather resistance), epoxy resin casting compounds (high mechanical strength).

- Low-voltage Scenarios

- Examples: Household appliance plugs, low-voltage switches

- Materials: Flame-retardant PC/ABS alloys (CTI 250-400 V, low cost), ceramic-filled PPO (contamination resistance).

IV. Testing and Validation Recommendations

High-voltage Testing: Perform inclined plane tests according to IEC 60587 (e.g., 4.5 kV, 50 drops of electrolyte) to observe whether tracking or burning occurs.

Low-voltage Testing: Determine CTI values according to IEC 60112 standard (100-600 V) to simulate durability in humid and contaminated environments.

Summary by Beiguang Jingyi Instrument Equipment Co., Ltd.

Selection should comprehensively consider voltage level, environmental severity, and cost:

- High-voltage: Prioritize materials with high CTI and arc resistance to avoid electrical breakdown.

- Low-voltage: Focus on surface contamination resistance, balancing CTI and cost.

In practical applications, compliance validation according to standards such as UL and IEC is also necessary.