Origin: Tianyun (ambient temperature: - 40 DEG C to + 95 DEG relative humidity: 23 DEG C of not more than 95% of atmospheric pressure: 80 ~ 101kpa nominal voltage: 24VDC voltage: 18vdc ~ 30VDC connected to the temperature: 5 plus or minus 5 DEG off temperature: not greater than 20 DEG C allows the passage of electric current: not less than 4a)