Thermal relay electrical symbols are how old and new ah,
1, the old and new standards that:
New standard: FR; old standard: RJ
The old standard used in the traditional Chinese Pinyin, referred to as RJ And now collectively referred to as the international, referred to as FR
2, the origin: thermal relay is a foreign language, from the Japanese サ ー マ ル リ レ ー, English is: from the thermal relay.
