Eaton Cutler-Hammer Digitrip RMS 910 Instructions Manual

Also see for Digitrip RMS 910: Instructions Instructional Leaflet Instruction leaflet

I.L. 29-889A Page 21actual overload or fault condition occur duringan in-service, test sequence, the protectionfunction will override the test function, and thecircuit breaker will trip automatically in accor-dance with the actual Time-Current settings.When performing tests on the Long Delay ele-ment, be aware that in addition to the standardprotection element, the Digitrip RMS 910 TripUnit also has a Long Time Memory function(LTM), which serves to protect load circuits fromthe effects of repeated overload conditions. (SeeNOTE 1 under section 3.3 Long Delay Time Set-ting.) The action of the LTM during primary injec-tion tests and during tests initiated from the TripUnit Test Panel under the “TEST AMPS” setting of“6T”, will advance the Long Delay Trip Time if multi-ple Long Delay Time tests are performed repeat-edly - as one might do in making single-phase testson each pole of a breaker in succession, for exam-ple. If there is any question, you may simply waitabout ten (10) minutes after a Long Delay Trip forthe LTM to reset. The LTM is not active during testsinitiated from the Trip Unit Test Panel under the‘TEST AMPS” settings of “1”, “2”, “3”, “8”, or “10”.To reset the LTM immediately:• Set the “TEST AMPS” to “1”.• Press and release the (Black) ‘TEST” push-button(timer will be running in the display window), and then• Quickly press and release the “TRIP RESET”pushbutton before the Trip Unit operates.• Now the LTM will be reset.When performing tests on the Ground Fault ele-ment, be aware that in addition to the standardprotection, the Digitrip RMS 910 Trip Unit alsohas a Ground Time Memory function (GTM),which serves to protect load circuits from theeffects of repeated (sputtering) ground arcs. (SeeNOTE under Section 3.9 Ground Fault Time DelaySetting.) Because the GTM resets quickly, it will notnormally affect ground fault test results, but ifGround Fault tests are repeated quickly, the GTMcan make the breaker appear to trip too soon.Note: To STOP a TEST initiated via the integral testpanel PRESS AND RELEASE THE “TRIP RESET”PUSH-BUTTON.4.4.1 Not Tripping the BreakerPlace the “TEST AMPS” selector switch (see Fig.9) in one of the six “No Trip” test settings, i.e., 1, 2,3, 8, or 10 x ln, or GF.Press and release the (Black) “TEST” push-but-ton—the test starts when the push-button isreleased, and the elapsed time will be displayedin the window. When the timer stops, the lighted“RED” cause of trip LED indicates the protectionfunction which operated.Should any of the various protection settings beless than the selected “No Trip” test value, then theLED related to that function will turn on signifyingsuccessful completion of the test action. Note: Dur-ing the long delay tests the Long Delay LEDflashes “RED”.Reset the Trip Unit by pressing and releasing the“TRIP RESET” push-button; all LEDs lighted by the“No Trip” test action should turn “OFF", and the dis-play will again show the value of the currentthrough the breaker. In the event that no one resetsthe Trip Unit after a test, it will wait for about three(3) hours, and then it will automatically revert backto its pretest status.1.2.3)3.4.4.4.2 Tripping the BreakerWARNINGCIRCUIT BREAKER OPERATING MECHANISMSOPEN AND CLOSE THE MOVING PARTS VERYFAST, AND WITH VERY HIGH ENERGY. TOUCHINGTHE MOVING PARTS DURING TEST OPERATIONSCAN CAUSE INJURY. KEEP CLOTHING, HANDS,FEET AND OTHER PARTS OF YOUR BODY WELLAWAY FROM ALL MOVING PARTS DURING TEST-ING. FOLLOW THE INSTRUCTIONS GIVEN FORTESTING YOUR SPECIFIC TYPE OF CIRCUITBREAKER, FOUND IN THE APPROPRIATE INSTRUC-TION LEAFLET LISTED IN SECTION 6.Make sure that the circuit breaker is carrying nocurrent. (See CAUTION notes under Section 4.1.)Note: In the event it is decided to perform a “ BreakerTrip Test” while load current is flowing, make surethe circuit breaker is carrying no more than 50% ofthe Long Delay Current Setting lr . The Trip Unit willNOT execute your instructions to Test itself, whenthe load current exceeds 50% of lr .4)1.F:T*NEffective May 1997