Thermal shock reflects the ability of a specimen to withstand the temperature after being stretched and/or coiled or bent on a round bar.
1.1 Sample Preparation
1.1.1 Park Line
Specimens shall be prepared as follows:
- For enameled wires whose conductor nominal diameter is less than or equal to 1.600mm, according to the provisions in 5.1.1 of GB/T4074.3-2008;
– For enameled wires with conductor nominal diameter greater than 1.600mm, according to GB/T4074.3-2008 5.2;
all
For film-wrapped wire with conductor nominal diameter less than or equal to 1.600mm, according to GB/T4074.3-2008 5.1.1
Regulation;
For the film-wrapped wire with conductor nominal diameter greater than 1.600mm, according to GB/T4074.3-2008 in 5.5.4.
1.1.2 Flat wire
Prepare the sample according to the provisions in 5.1.2 of GB/T4074.3-2008, but only the wide side can be bent (with the narrow side size).
1.2 Test procedure
Place the sample in a forced-air oven and heat for 30 in, at a temperature of ±5°C as specified in the relevant product standard. Remove the test from the oven
Cool the sample to room temperature, and then use the magnifying glass specified in Table 1 to check whether the insulation is cracked.
1.3 Test results
For round wire, test three samples; for flat wire, test two samples. Any detected cracks should be recorded.
