The Difference Between High Voltage Tracking Test and Tracking Index Test

High voltage tracking test apparatus and tracking index test apparatus are both test equipment used to test certain physical properties of insulating materials, but the physical properties tested by the two equipment are different, therefore, the test standard base on the two equipment are also different, the following are the main differences between the two equipment.

1. Definition

The high-voltage tracking tester is to simulate the power frequency (48Hz-62Hz), using liquid pollutants and inclined specimen to evaluate the resistance to tracking and corrosion of electrical insulating materials under severe ambient conditions. The electrical tracking refers to the continuous deterioration of the solid insulating surface due to the discharge of a local area and the formation of conductive or partial conductive channels.

The tracking index test apparatus is to simulate the conductive substances deposited on the surface of insulating material caused by different polarity live parts of household appliance in actual use, and check whether the conductive substances would caused creepage, short circuit breakdown and fire hazard on the surface of insulating materials, and then to determine its comparative tracking index and proof tracking index. The electrical tracking means that under the combined action of electrical stress and contaminated medium, conductive channels are gradually formed on the surface of the solid insulating material and/or inside the sample.

2. Standard

The high-voltage tracking test apparatus is designed base on IEC60587.

The tracking index test apparatus is designed base on IEC60112.

3. Test principle

The test performs by high-voltage tracking test apparatus uses liquid contaminants and inclined specimen to evaluate the resistance to tracking and corrosion of electrical insulating materials under severe ambient conditions.

The tracking index test is performs on the surface of the solid insulating material, a certain voltage is applied between the platinum electrodes (2 mm × 5 mm) , and drops the pollution liquid (0.1% NH4CL) with specified droplet volume in fixed height (35mm) for 30s to evaluate the resistance of the surface of solid insulating materials under the combined action of electric field and contaminated medium, and its Comparative tracking index (CTI) and proof tracking index (PTI) are determined.

4. Test Circuit

The high-voltage tracking test is carried out under high voltage, the safety bar should be used for access. The power frequency is 45Hz~65Hz, the output voltage can be adjusted to about 6kv and stabilized at ±5%, the rated current for each sample should not be less than 0.1A. The preferred test voltages are 2.5KV, 3.5KV and 4.5KV.

The circuit principle of the tracking index test is to apply a sine-wave voltage on the electrode, which varies between 100V and 600V, and the frequency is 48Hz to 62Hz. The voltage measurement device indicates a true effective value with a maximum error of 1.5%. The power of the power supply should not be less than 0.6kVA. The variable resistor should be able to adjust the short-circuit current between the electrodes to 1.0A±0.1A, and at this current, the voltage drop indicated on the voltmeter should not exceed 10%, and the maximum error of the short-circuit current measuring device is ±3% . The input power voltage of the test device should be sufficiently stable. When the effective value of the current is 0.5A, the relative tolerance is ±10%, for 2.00s, and the relative tolerance of the device is ±10%, the overcurrent should act.

5. Material of electrodes

For high-voltage tracking test apparatus, the electrodes, fixing device and assembly parts for electrode connection (like screws) should be made of stainless steel.

For tracking index test apparatus, the electrodes should be made of platinum with a minimum purity of 99%, between the two electrodes should have a cross-section (5±0.1) mm with a 30°±2° inclined plane. The blade of the inclined plane is approximately 0.01mm±0.1mm wide on a flat surface.

6. Size of specimen

For the high-voltage tracking test, the specimen should be 50mm*120mm, and thickness 6mm.

For tracking index test, the specimen can be any with a very flat surface, as long as the surface is sufficient to ensure that no liquid flows out of the edge during the test. The thickness of the sample should be 3mm or thicker, and each material sample can be overlapped to obtain a thickness of at least 3mm.

Note: Although a smaller size can be used, it is recommended that the plane size should not be less than 30mm*20mm to reduce the edge loss of the electrolyte flowing out of the sample.

7. Test voltage

For the tracking index test, the voltage applied between the two electrodes is 100V~600V.

For high-voltage tracking test, the test voltage is 1000V~6000V.