- Rated Functioning Temperature (Tf)
- In the Electrical Appliance and Material Safety Law it is called as nominal operating temperature while in UL60691, C-UL CAN/ CSA-E691-94, EN60691 as rated functioning temperature. The operating temperature against the nominal operating temperature when operated at the specified temperature rising speed as detection current was flown through thermal-link is stipulated to be within 7°C in the Electrical Appliance and Material Safety Law and +0°C and -10°C in the standards conforming to lEC Standards. The nominal operating temperature (rated functioning temperature) as adopted by our company satisfies the requirements of both standards. The symbols for the nominal operating temperature are specified.
- Functioning Temperature
- It is the temperature at which thermal-links operate in oil bath which goes up 0.5°C per minute under current below 0.1A. It is a yardstick for using cutoffs, but not the rated temperature by any safety standard.
- Holding Temperature (Th)
- When current are flown into thermal-links, self heat generation is caused in proportion to the value of current and the thermal-links operate at ambient temperature lower than at the time under no load. Safety standards based on lEC standards (IEC60691), therefore, obligate the setting of maximum holding temperature at which no fuse will start working even if rated current was continuously flown for 168 hours, which is called the holding temperature. The Safety standards specify to use the symbol of Th.
- Maximum Temperature Limit (Tm)
- It is defined by safety standards conforming to the lEC standards (IEC 60691) as the maximum temperature at which no re-conduction will be caused for ten minutes for thermal-links, operated with no force imposed on them or lead wires. The Safety standards specify to use symbol of Tm.