Location: (ambient temperature: -40 ℃ ~ +95 ℃ Relative Humidity: 23 ℃ not more than 95% when the atmospheric pressure: 80 ~ 101kpa Nominal Voltage: 24VDC Operating Voltage: 18VDC ~ 30VDC connected to the temperature: 5 ± 5 ℃ off Opening temperature: not more than 20 ℃ allows current: no less than 4A)