Eaton Cutler-Hammer Digitrip RMS 510 Instructions Manual

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

AD 33-855-4 Page 11SECTION 3 THE DIGITRIP RMS TRIPSYSTEM3.1 Digitrip BMS Overcurrent ProtectionThe Digitrip RMS Retrofit Kits covered by thisApplication Guide are designed to replace theexisting Trip System employed on the Breakerselected for Retrofitting.All Digitrip RMS Retrofit Kits provide basicOvercurrent Protection, which includes a selectedcombination of Long Time (L), Short Time (S),lnstantaneous (l), and Ground Fault Time (G) DelayTrip Functions. Five major components comprisethe Digitrip RMS Ti'ip System: the Current Sensors;Auxiliary CT Module; Digitrip Trip Unit; Rating Plug;and the Direct Trip Actuator (DTA). These compo-nents are interconnected by use of the variouswiring harnesses to make up the Digitrip RMS TripSystem. Breaker interface diagrams for DigitripRMS 510 through 910 are provided in Sections 4through 7. These diagrams show the major DigitripRMS components and their interconnections.Wiring diagrams for each of the wiring harnessesare shown in Section 12.Figure 3-1 shows the major components of theDigitrip Retrofit System and their interconnections.The following sections describe the function andoperation of each component.3.2 Current Sensors and Sensor WiringHarnessThree single or multi-tapped Current Sensors (oneper phase) are located at the rear of the Breaker.The Sensors pass information to the Auxiliary CTModule and the Trip Unit about the primary currentlevel passing through the Breaker. All the energyrequired to power the Digitrip RMS Trip System isproduced by the Current Sensors.The Current Sensors are connected to a terminalblock strip on the Auxiliary CT Module by theSensor Wiring Harness. The Current Sensor Tapratio connected, in concert with the Rating Plug,determines the Continuous Current Rating (ln) ofthe Breaker. At rated primary current, the CurrentSensors provide 5 ampere nominal current inputsto the Auxiliary CT Module.3.3 Auxiliary GT Module and Auxiliary CTHarnessThe Auxiliary CT Module encloses three auxiliaryphase Current Transformers, which reduce the 5ampere nominal inputs from the Current Sensorsto the milliampere level required for the DigitripRMS Trip Unit electronics. When Ground Fault (G)protection is selected, a Ground Auxiliary CurrentTransformer is also provided, which performs thesame function.A 7-point terminal block strip is mounted to theAuxiliary CT Module. Terminals A through G termi-nate the inputs from the Current Sensors via theSensor Wiring Harness. Terminals OP and ONconnect the Trip Signal Outputs to the Direct TripActuator (DTA) via the Sensor Wiring Harness orDTA Wiring Harness. A 12-point female CT Plug-inBlock is mounted on the right hand side of themodule, which receives the male plug of theAuxiliary CT Harness. The Auxiliary CT Harnessalso has a 10-pin black plug, which plugs into theTrip Unit to connect the Auxiliary CT lnputs to the'Trip Unit and receives the Trip Unit trip signaloutputs. Refer to Figure 12-6 for Auxiliary CTModule wiring.3.4 Digitrip RMS Trip Unit and PowerRelay Module (ATR)The 1O-Series Digitrip RMS Trip Units (510through 910 Kits), Figure 3-1 , are designed topermit flexibility in Retrofit applications. They arephysically repackaged versions of the original1 OO-Series Digitrip RMS Trip Units that were usedon Cutler-Hammer DS and SPB Breakers. TheRMS Trip Units have the same features andoptions and have identical characteristic curves,adjustments, and electrical pedormance.The Digitrip RMS Trip Unit is a microprocessorbased protective device that provides true RMSsensing means for proper correlation with thermalcharacteristics on conductors and equipment.Digitrip RMS Trip Units are available in four mod-els, RMS 510, 61 0, 81 0, & 91 0. These models areavailable in horizontal or vertical labeling anddisplay orientations.Eflective 9/01 ElT.il