EM500 low voltage motor protection products for the low-voltage AC 380V electric motor design, set protection, measurement, signaling and other functions into one, focused to achieve a comprehensive protection of low voltage motor, measurement and operation and control. 1.2 Use of the environment a) Ambient temperature: -10 ℃ ~ + 55 ℃, b) Storage temperature: -25 ℃ ~ + 70 ℃, in the limit amount is not energized, the device does not appear irreversible changes in the temperature returns, the device should can work; c) relative humidity: no more than 85%; d) Atmospheric pressure: 86kPa ~ 106kPa; e) the place of use does not allow explosive medium, surrounding medium should not contain corrode metal and damage the insulation of gas and electric media allowed full steam and there exist serious mold; this device has the main technical characteristics are: a) set protection, measurement, signaling and other functions; b) has a ground fault protection, overcurrent protection, overvoltage protection, under voltage protection, thermal protection, unbalance protection, starting time is too long protection, stall protection, TE protection for increased safety motor protection and phase reversal protection 11 types