User Manual

ManualsBrandsRockwell Automation ManualsEquipmentLow-Voltage Switchgear and Controlgear

2.3.4.4 Current limiting protective equipment ................................................................... 2-11

2.3.4.5 Coordination of electrical equipment .................................................................... 2-12

2.3.4.5.1 Coordination in respect of the switching capacity of the contactor

(overcurrent selectivity)......................................................................................... 2-12

2.3.4.5.2 Coordination with respect to the operability after a short-circuit ........................... 2-13

2.3.4.6 Short-circuit switching capacity............................................................................. 2-14

2.3.4.6.1 Rated short-circuit making capacity I

................................................................. 2-14

2.3.4.6.2 Rated short-circuit breaking capacity I

and I

.................................................... 2-14

2.3.5 Thermal protection................................................................................................ 2-15

2.3.5.1 Ambient temperature ............................................................................................ 2-15

2.3.5.2 Operational overcurrents, heavy-duty starting...................................................... 2-15

2.3.6 Life span ............................................................................................................... 2-16

2.3.6.1 Prospective service life......................................................................................... 2-17

2.3.6.2 Mechanical life span ............................................................................................. 2-17

2.3.6.3 Electrical life span................................................................................................. 2-17

2.3.7 Intermittent and short-time duty, permissible frequency of operation ................... 2-20

2.3.7.1 Intermittent duty and relative ON-time .................................................................. 2-22

2.3.8 Rated frequency and harmonics........................................................................... 2-24

2.3.9 Safety clearances ................................................................................................. 2-24

2.3.10 Mounting position.................................................................................................. 2-25

2.3.11 Protective separation............................................................................................ 2-25

2.3.12 Site altitude........................................................................................................... 2-26

2.3.13 Shock and vibration .............................................................................................. 2-26

2.4 Specific application conditions and switching tasks...................................... 2-27

2.4.1 Parallel and series connection of poles ................................................................ 2-27

2.4.1.1 Parallelling ............................................................................................................ 2-27

2.4.1.2 Series connection ................................................................................................. 2-27

2.4.2 AC switchgear in DC applications......................................................................... 2-28

2.4.3 Applications at supply frequencies < 50 Hz and > 60 Hz. Effect of harmonics.... 2-29

2.4.3.1 Effect of the supply frequency on the thermal load............................................... 2-29

2.4.3.2 Effect of the supply frequency on the switching capacity ..................................... 2-31

2.4.3.3 Performance of release units at supply frequencies < 50 Hz and > 60 Hz........... 2-32

2.4.3.4 Switchgear used with soft starters........................................................................ 2-32

2.4.3.5 Switchgear for use with frequency converters (inverters)..................................... 2-33

2.4.4 Application of four-pole switchgear devices.......................................................... 2-35

2.4.4.1 Applications of switchgear with 4 NO contacts..................................................... 2-35

2.4.4.2 Applications of switchgear with 2 NO and 2 NC contacts..................................... 2-36

2.4.4.3 Applications of switchgear with 3 NO and 1 NC contact....................................... 2-37

2.4.5 Application of circuit breakers in IT networks ....................................................... 2-37

2.4.6 Switchgear for safety applications ........................................................................ 2-38

2.4.6.1 Mechanically linked contacts ................................................................................ 2-38

2.4.6.2 Mirror Contacts ..................................................................................................... 2-39

2.4.7 Installations in hazardous atmospheres ............................................................... 2-40

2.4.7.1 History, guidelines and regulations....................................................................... 2-40

2.4.7.2 Classification of hazardous areas......................................................................... 2-41

2.4.7.3 Motors for hazardous areas.................................................................................. 2-43

2.4.7.4 Protection of motors of ignition protection type Increased Safety “e” ................... 2-45

2.4.7.5 ATEX 100a (Directive 94/9/EC)............................................................................ 2-46

2.4.7.6 IECEx and other approval schemes for hazardous areas .................................... 2-47

LVSAM-WP001A-EN-P - April 2009

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