5.1.8.1 PVC and TPE insulations
The insulation shall show no cracks when specimens of finished unjacketed cords and specimens of the
individual conductors from jacketed cords and types CXWTc, CXTWu, and TXc are exposed to a
temperature of 121 °C ± 2 °C for PVC or TPE rated at 60 °C, or 150 °C ± 2 °C for TPE rated in excess
of 60 °C for 1 h while wound six close turns around a mandrel having a diameter as shown in Table 43.
The specimen shall show no cracks when unwound from the mandrel after cooling to room temperature
从标准上看,有裂纹显然是不能接受的!(The specimen shall show no cracks when unwound from the mandrel after cooling to room temperature)