Eaton Cutler-Hammer RMS 510 Instructions Manual

Also see for Cutler-Hammer Digitrip RMS 510: Instructions Instructional Leaflet Instruction leaflet

I.L. 29-885B Page 115.2 When To TestTests can be conducted with the breaker in the “con-nected” cell position while carrying load current. How-ever, as stated in the caution note in Section 5.1, goodpractice will limit circuit breaker in-service “trip tests”,where required, to maintenance periods during times ofminimum load conditions. Testing, prior to start-up canbest be accomplished with the breaker out of its cell or inthe “Test”, “Disconnected” or “Withdrawn” (or Removed)cell positions.Note: Since time-current settings are based ondesired system coordination and protectionschemes, the protection settings selected and presetin accordance with Section 4.0 above should not bealtered during or as a part of any routine testsequence.the current is not less than 10% of thebreaker frame (or current sensor) rating;be sure the “GREEN” Unit Status LED (inthe lower right corner of the trip unit (SeeFigs. 1 and 5) is blinking on and off (indi-cating that there is enough current flowingto provide the power necessary to operatethe trip unit). In the event the Unit StatusLED is either lighted “GREEN” or “OFF”continuously, there is NOT enough cur-rent flowing to power the trip unit; andan APM (See Fig. 7) should be installedbefore proceeding with the test.and b) the current is not more than 50% of theLong Delay Current Setting (/,.); becausethe trip unit will not execute your testinstructions when it senses that thecurrent through the breaker exceedsthe 50% level.When performing tests on the Long Delay ele-ment, be aware that in addition to the standardprotection element, the Digitrip RMS 510 Trip Unitalso has a Long Time Memory function (LTM),which serves to protect load circuits from theeffects of repeated overload conditions. (SeeNOTE 1 under Section 4.3 Long Delay Time Set-ting.) The action of the LTM will have the sameeffect of advancing the Long Delay Trip Time ifmultiple Long Delay Time tests are performedrepeatedly - as one might do in making singlephase tests on each pole of a breaker in succes-sion, for example. If you have sufficient experiencein performing tests with this kind of accelerated triptiming, you may be comfortable with the results oftests performed in quick succession. However, ifthere is any question, you may simply wait aboutten (10) minutes after a Long Delay Trip for theLTM to reset, before you check the next pole.a)5.3 Test ProvisionAs indicated in Fig. 5, six different “Test Amps” settings(1, 2, 3, 6T, 8 and 10X ln) are available fortesting thephase elements of the trip unit, and two (GF, GFT) areprovided for testing the ground elements.3)CAUTIONA SETTING OF EITHER 6T OR GFT WILL TRIP THECIRCUIT BREAKER. (SEE SECTION 5.4.3 BELOW.)For any combination of the phase protection settings, anappropriate “No Trip” condition can be set to test the longtime, short time and instantaneous trip settings withouttripping the circuit breaker.In the “GF” test position, the level of test current based onln, is adequate to demonstrate the operating condition ofthe trip unit without tripping the circuit breaker. This is afunctional check only, not a calibration.5.4.1 Control PowerFor testing the trip unit, an optional Auxiliary Power Mod-ule (Cat. No. PRTAAPM) as shown in Fig. 7 is recom-mended. This Auxiliary Power Module, which operatesfrom a separate 120 Vac supply, may be used when adrawout circuit breaker is in any of its four cell positions,i.e., “Connected”, “Test”, “Disconnected” and “With-drawn” (or “Removed.”)Note: For Testing Purposes Only: When using anexternal single phase current source to test low levelground fault current settings, it is advisable to usethe Auxiliary Power Module (APM) (See Fig. 7). Espe-cially when the single phase current is low, without5.4 Conducting TestsBefore starting any test sequence, check theUnit Status (Green LED) in the lower right corner ofthe trip unit (See Figs. 1 and 5) to be sure it is blink-ing on and off about once each second, which indi-cates that the trip unit is functioning normally. In theevent the Unit Status LED is not blinking, install anAuxiliary Power Module (APM) (See Fig. 7), or ifyou have one already, check to see that it is con-nected correctly.If the circuit breaker is carrying current, checkfor the following conditions:1)2)F:T'NEffective May 1997