ABB CRN-1 Instruction Leaflet

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ABB CRN-1 Instruction Leaflet Manual pdf 1 page image

ABB Automation Inc.Substation Automation and Protection DivisionCoral Springs, FL 33065Instruction LeafletAll possible contingencies which may arise during installation, operation or maintenance, and alldetails and variations of this equipment do not purport to be covered by these instructions. If furtherinformation is desired by purchaser regarding this particular installation, operation or maintenanceof this equipment, the local ABB Power T&D Company Inc. representative should be contacted.ABBABBABBABB! CAUTIONBefore putting relays into service, remove allblocking which may have been inserted for thepurpose of securing the parts during ship-ment, make sure that all moving parts operatefreely, inspect the contacts to see that theyare clean and close properly, and operate therelay to check the settings and electrical con-nections.1.0 APPLICATIONThese relays have been specially designed andtested to establish their suitability for Class 1E appli-cations in accordance with the ABB Power T&DCompany program for Class 1E Qualification Testingas detailed in bulletin STR-1.“Class 1E” is the safety classification of the electricequipment and systems in nuclear power generatingstations that are essential to emergency shutdown ofthe reactor, containment isolation, cooling of thereactor, and heat removal from the containment andreactor, or otherwise are essential in preventing sig-nificant release of radioactive material to the environ-ment.The type CRN-1 relay is a single phase directionallycontrolled timing relay used to protect ac generatorsfrom motoring. When such a condition occurs andpersists for a predetermined time interval, the gener-ator may be tripped or an alarm sounded. TheCRN-1 may also be used to sense lagging powerfactor load flow in an abnormal direction. The direc-tional unit has 30 degree maximum torque character-istics and the timer unit is adjustable fromapproximately 2 to 40 seconds.2.0 CONSTRUCTION AND OPERATIONThe relay consists of a directional unit, a timing unit,and an indicating contactor switch unit.These units have been specially designed to meetthe fragility requirements of a seismic environment.In most cases, the construction is similar to the non-seismic units except spring restraint is greater andtherefore more power is required to make them oper-ate.The timer unit is similar to Type CV relay described inI.L. 41-201.4.The CV unit contains a special shield covering thespring, located above the disc, to prevent the springfrom contacting grounded elements during extremevibrations.The ICS has a single operate rating and requiresspecial calibration procedures to make it less sensi-tive to vibration.The internal schematic of the CRN-1is shown in figure 1, page 7.2.1 CV TIMER UNIT (T)A spring shield covers the reset spring of the CV unit.To remove the spring shield, requires that the damp-Effective: July 1999Supersedes I.L. 41-251.21B, dated July 1998( ) Denotes Change Since Previous IssueType CRN-1Reverse Power Relay50 and 60 HzClass 1-E Applications41-251.21CR