Eaton Digitrip RMS Series Instructional Leaflet

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

4.4 Digitrip RMS 910The Digitrip RMS 910 Trip Assembly is similar to the DigitripRMS 810. It is a communicating trip unit that provides allthe functions described in Section 4.3 plus the addition ofthe following locally displayed and remotely communicatedfeatures:1. Phase to Phase Voltages Vab, Vbc, Vca2. System Power Factor (PF)3. Total Harmonic Distortion (THD) for Ia, Ib, IcThe THD calculation also includes the individual harmoniccurrents up to the 27th harmonic as a percentage of thefundamental. Also included with the THD are provisions forwaveform capture information via a host computer. Detailedinformation is provided in I.L. 29-889.4.5 Digitrip OPTIM Model Consider-ationsTrip unit testing is carried out by using the OPTIMizer HandHeld Programmer, the Breaker Interface Module, or aremote computer to select values of test current within arange of available settings. Basic protection functions arenot affected during test operations. The testing capability isnot intended for live primary current interruption. Two typesof tests are possible, the “No Trip” and the “Trip” tests.Testing is not permitted to proceed if there is greater than0.4 per unit of current flowing on a phase circuit or 0.2 perunit of current on a ground circuit. The maximum permittedcurrent value can be determined by multiplying the appro-priate per unit value (0.4 or 0.2) times the ampere rating ofthe installed rating plug. An auxiliary power module (Cat.No. PRTAAPM) can be used to bench test a trip unit whenthe auxiliary power module is connected to a 120V 50/60Hzsupply. CauTION“TrIp” TEsTINg Of a CIrCuIT BrEakEr IN ThE CEll “CON-NECTED” pOsITION Is NOT rECOmmENDED. ThE TrIppINgOpEraTION Of ThE CIrCuIT BrEakEr wIll CausE sErVICE DIs-rupTION aND pOssIBly pErsONal INJury rEsulTINg frOmuNNECEssary swITChINg Of CONNECTED EQuIpmENT. ThIskIND Of TEsTINg shOulD ONly BE CONDuCTED IN ThE “TEsT,”“DIsCONNECTED” Or “rEmOVE” CEll pOsITIONs.4.6 Digitrip OPTIM 750Digitrip OPTIM 750 Trip Units provide true rms sensing andutilize a fixed interchangeable rating plug to establish thecontinuous trip rating of the circuit breaker. Rating plugs areinterlocked to prevent use between different circuit breakertypes.Precise system coordination is provided by the followingtime-current curve shaping adjustments:1. Long delay pickup2. Long delay time with selectable I2t or I4t curveshaping3. Short delay pickup4. Short delay time with selectable flat or I2t curveshaping5. Instantaneous pickup6. Ground fault pickup7. Ground fault time with selectable flat or I2t curve shapingThe trip units also have a selectable powered/unpoweredthermal memory to provide protection against cumulativeoverheating should a number of overload conditions occur inquick succession.The trip unit information system utilizes battery backup LEDsto indicate the trip mode following an automatic trip opera-tion. The LEDs are complemented by trip event informa-tion that is stored in memory after a trip condition. This tripinformation can then be accessed via the OPTIMizer HandHeld Programmer, the Breaker Interface Module, or over theIMPACC System. A trip reset pushbutton is provided on thetrip unit to turn off the LED indication after an automatic trip.The battery status is also LED indicated through the use of apushbutton.Selectable early warning alarms, capable of being indicatedlocally and remotely, are provided to help keep a systemoperating and productive.All OPTIM Trip Units are capable of monitoring the followingdata:1. Steady-State value of phase, neutral, and ground currents2. Minimum and maximum current values3. Average demand current4. Cause of trip (Long Delay, Short Delay, Instantaneous orGround Fault)5. High load current alarm6. Magnitude of fault current responsible for an automatictrip operationMonitoring and ControlTrip units are capable of two way communication via anetwork twisted pair for remote monitoring and control. Thecircuit breaker, through the trip unit, is able to respond toopen and close commands via the communication network.To close the breaker, an electrical operator or spring releaseoption is required.Effective July 2010 Instructional Leaflet IL8700C39-0410 eaTOn CORPORaTIOn www.eaton.com