10.07.2015 Views

Arc Protection Relay REA 10_ - APE Distribuidor ABB

Arc Protection Relay REA 10_ - APE Distribuidor ABB

Arc Protection Relay REA 10_ - APE Distribuidor ABB

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

<strong>Arc</strong> <strong>Protection</strong> <strong>Relay</strong> <strong>REA</strong> <strong>10</strong>_1MRS750929-MBGDesign <strong>Arc</strong> protection relay <strong>REA</strong> <strong>10</strong>1Overcurrent detection unitThe selection switch is used to select betweenthree-phase current measurement or twophaseand neutral current measurement.Three-phase current measurementThe three-phase currents are measured viatransformers. When the current on one phaseexceeds the selected reference level, an overcurrentsignal is activated.The selection switch is used to select the currentreference level for the current inputs L1,L2 and L3. The available current level settingsare 0.5, 1.0, 1.5, 2.5, 3.0, 5.0 and 6.0times the rated current (In = 1.0 A or 5.0 A).Two-phase and neutral current measurementWhen the current in L1, L3 or L2 (neutralcurrent) exceeds the selected reference level,an overcurrent signal is activated.The available current level settings for L1 andL3 are 0.5, 1.0, 1.5, 2.5, 3.0, 5.0 and 6.0 timesthe rated current (In = 1.0 A or 5.0 A).The available current level settings for L2 are0.05, 0.1, 0.15, 0.25, 0.3, 0.5 and 0.6 timesthe rated current (In = 1.0 A or 5.0 A).Light detection unitThe light captured by the sensor is amplifiedand compared to the pre-selected light referencelevel. Once the light exceeds the set referencelevel, a light signal is activated.The selection switch is used to activate thearc detection sensor.The selection switch is used to select automaticor manual light reference level.If the automatic reference level is selected,the unit forms the reference level based onthe backlight intensity measured by the sensor.When the manual reference level is selected,the unit forms the reference level based onthe value that was selected with the light referencelevel adjustment potentiometer on thefront panel.The sensor fiber condition is monitored bysending a test pulse through the fiber. If a testpulse is not received at regular intervals at theother end of the fiber loop, the “Sensor Fault”LED and the self-supervision LED “IRF” areactivated, and the IRF relay resets.If the sensor-monitoring feature is notneeded, it can be deactivated by using theselection switch.Sensitivity of sensorsFig. 1A050616Sensitivity of <strong>REA</strong> <strong>10</strong>_ sensors at variousbacklight compensation settingsThe intensity of a high-current arc light in atwo- or three-phase short circuit can be tensof thousands of luxes. The intensity of a normaloffice lighting is 200-300 luxes.The exact determination of the detectingreach of the light sensors is difficult, becausethe detecting reach depends on several factors:• Light source energy• Fiber length• Reflectances• Backlight compensation settingsSensitivity of fiber sensorsThe incidence angle of the light is not relevantwith fiber sensors.When an arc protection system is designed,the length of the sensor fiber per one switchgearcompartment must be selected accordingto the possible short-circuit or earth-fault current,and the distance between the sensor andarc. When selecting sensor fiber length, referto the table 1.4

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!