The IEC 61439-1 sets the thermal limit in busbars working at the maximum working load. Here, 140°C (which is 105K over the ambient temperature of 35°C) is the upper safe temperature limit. With the aid of a correction factor (k2), the continuous currents specified in the follow-ing table may be adjusted to alternative oper-ating temperatures. This assumption is widespread in workshops, on job sites, and even during procurement reviews. However, real-world testing and. Temperature monitoring in high-voltage busbar systems is vital for preventing faults, yet difficult due to electrical hazards, limited accessibility in switchgear cabinets, and interference risks in traditional contact-based methods.