6/28/2010 10:03 AM | |
Joined: 5/28/2008 Last visit: 8/27/2024 Posts: 4515 Rating:
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Hello all, EN 60947-4-1 and IEC 60947-4-1 make a distinction between two different types of coordination, which are designated type of coordination "1" and type of coordination "2". Any short-circuits that occur are cleared safely by both types of coordination. The only differences concern the extent of the damage caused to the device by a short-circuit. Type of coordination "1" The fuseless load feeder may be non-operational after a short-circuit has been cleared. Damage to the contactor or to the overload release is permissible. For 3RA1 load feeders, the motor starter protector itself always achieves type of coordination "2". Type of coordination "2" There must be no damage to the overload release or to any other components after a short-circuit has been cleared. The 3RA1 fuseless load feeder can resume operation without needing to be renewed. At most, welding of the contactor contacts is permissible if they can be disconnected easily without any significant deformation. http://support.automation.siemens.com/WW/view/en/35681462 Hope this helps. |
Last edited by: Ayman Elotaify at: 6/28/2010 10:11 AMAyman Elotaify |
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