Description: time period during which all the performance requirements are met; Name: usefull life
Description: Time interval from first use until the instant when a limiting state is reached ; Name: useful life
Description: norm/stipulation describing the explosion protection. The explosion protection type, the device category, the temperature class as well as the device / explosion group are taken from this norm. The type and number of the norm/stipulation with issue year and issue month must be given; Name: Reference norm of the explosion protection of the electric motor