Eaton Cutler-Hammer RMS 510 Instructions Manual

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

I.L. 29-885BPage 6Note: If a breaker (M) receives a Zone Interlockingsignal from another breaker (F), but the fault currentlevel is less than the trip unit setting for breaker (M),the signal from the other breaker (F) will not causebreaker (M) to trip.Notes:1 This switch has eight (8) positions, and seven (7)of them show “D/S” in the window, while ONLYONE position shows “[BLANK]”.2 When the "OVERRIDE/” window shows“ [ BLANK]” , the only fast-acting high short-circuitprotection available is the OVERRIDE [FixedInstantaneous]. (See 3.5 below.)CAUTIONIF ZONE INTERLOCKING IS NOT TO BE USED (I.E.STANDARD TIME-DELAY COORDINATION ONLY ISINTENDED), THE ZONE INTERLOCKING TERMINALSMUST BE CONNECTED WITH JUMPER WIRES, ASSPECIFIED ON THE CONNECTION DIAGRAMS FORYOUR BREAKER (SEE SECTION 9.0), SO THE TIME-DELAY SETTINGS WILL PROVIDE THE INTENDEDCOORDINATION.For an example of how Zone Selective Interlocking maybe used, See Appendix A.3.5 OVERRIDE (Fixed Instantaneous)(For Types LS And LSG Trip Units Only)When the Digitrip RMS 510 Trip Unit is not equipped withan adjustable instantaneous setting, i.e., types LS orLSG, the Fixed Instantaneous “Override” analog trip cir-cuit is automatically pre-set to a value no greater than theshort-time withstand current rating of the circuit breakerin which the trip unit is installed. Since the specific valuesvary for different circuit breaker types and ratings, refer totime-current curves, listed in Section 9, for the valuesapplicable to your breaker. If breaker trips due to highinstantaneous current, the “OVERRIDE” LED will light“RED”.4.0 PROTECTION SETTINGS4.1 GeneralPrior to placing circuit breaker in operation, each trip unitprotection setting must be set to the values specified bythe engineer responsible for the installation. The numberof settings that must be made is determined by the pro-tector model supplied as illustrated in Figs. 2.1 through2.6. Each setting is made with a rotary switch, using asmall screwdriver. The selected setting for each adjust-ment appears in its respective rectangular viewing win-dow as illustrated in Fig. 1.The installed rating plug establishes the maximum con-tinuous current rating of the circuit breaker (ln). Instanta-neous and ground current settings are defined inmultiples of (ln).To illustrate the effect of each protection curve setting,simulated Time-Current curves are pictured on the faceof the trip unit. The rotary switch to make each setting islocated nearest that portion of the simulated Time-Cur-rent curve it controls. Should an automatic “trip” occur (asa result of the current exceeding the pre-selected value),the LED in the appropriate segment of the simulatedTime-Current curve will light “RED” indicating the reasonfor “trip”.The available settings, along with the illustrated effect ofchanging the settings, are given in Figs. 4.1 through 4.7.3.6 Zone InterlockingZone Selective Interlocking (or Zone Interlocking) isavailable (see Fig. 3) for Digitrip RMS Trip Units havingShort Delay and/or Ground Fault protection. Zone Selec-tive Interlocking provides the fastest possible tripping forfaults within the breaker’s zone of protection, and yet alsoprovides positive coordination among all breakers in thesystem (mains, ties, feeders and downstream breakers)to limit the outage to the affected part of the system only.When Zone Interlocking is enabled, a fault within thebreaker’s zone of protection will cause the RMS DIG-ITRIP trip unit to:Trip the affected breaker instantaneously,and at the same timeSend a signal to upstream RMS DIGITRIPtrip units to restrain from tripping immedi-ately. The restraining signal causes theupstream breakers to follow their set coor-dination times, so that only the minimumservice is disrupted, while the fault iscleared in the shortest time possible.(This signal requires only a single pair of wires from theoutput terminals of the downstream breaker’s trip unit tothe input terminals of the upstream breaker’s trip unit. Forspecific instructions see the applicable connection dia-grams for your breaker listed in Section 9.0.)a)b)F:T*N Effective May 1997