Electronic Trip Unit for SB Encased Systems Breakers

1 Electronic trip unit forSB Encased Systems BreakersInformation and Instruction GuideCircuit breaker indicators shown in this booklet are for illustration purposes only. Circuitbreakers are to be installed in Discharged and Open positions information contained herein is general in nature and not intended for specific appli-cation purposes. It does not relieve the user of responsibility to use sound practices in application, installation, operation, and maintenance of the equipment purchased. Siemensreserves the right to make changes in the specifications shown herein or to make improve-ments at any time without notice or obligations. Should a conflict arise between the generalinformation contained in this publication and the contents of drawings or supplementarymaterial or both, the latter shall take *Authorized and qualified personnel For the purpose of this manual a qualified person is one who is familiar with the installation,construction or operation of the equipment and the hazards involved.

2 In addition, he has thefollowing qualifications:(a) is trained and authorizedto de-energize, clear, ground, and tag circuits and equipment in accordance with established safety practices.(b) is trainedin the correct care and use of protective equipment such as rubber gloves,hard hat, safety glasses or face shields, flash clothing, etc., in accordance with estab-lished safety practices.(c) is trainedin rendering first instructions do not purport to cover all details or variations in equipment, nor to provide for every possible contingency to be met in connection with installation, operation,or maintenance. Should further information be desired or should particular problems arisewhich are not covered sufficiently for the purchaser s purposes, the matter should bereferred to the local sales office, listed on back of this instruction contents of this instruction manual should not become part of or modify any prioror existing agreement, commitment or relationship.

3 The sales contract contains the entireobligation of Siemens Energy & Automation, Inc. The warranty contained in the contractbetween the parties is the sole warranty of Siemens Energy & Automation, Inc. Any state-ments contained herein do not create new warranties or modify the existing voltage. WIll cuase death of serious off and lock out all power supplying the device priorto cover(s) removal or while cover(s) are removed andwhen installing any internal or external the cover(s) and shield(s) before power supplyingthis device is turned trip unit for Siemens Type SB Systems BreakersTable of ContentsInformation and Instructions2-5 Electronic trip unit 2 Overcurrent Protection Configurations2 RMS Current Sensing 3 Systems breaker Frame Sizes 3 Systems breaker Frame Ampere Ratings 3 Rating Plugs 3 Principles of Operation 4 Functional Diagram 5 Installation Instructions 6-11 Installing the trip unit 6-8 Removing the trip Unit9 Removing/Replacing Plexiglass Cover10-11 Inserting/Removing the Rating Plug 10-11 Operations12-21 Electronic trip unit Functions12 Setting the Fault Protection Adjustments 12 Current Shaping Fault Protection Adjustments 13 Long Time Fault Protection14 Short Time

4 Fault Protection 15 Instantaneous Fault Protection16 Ground Fault Protection 17 Ground Fault Sensing Schemes 18 Example Time Current Curve (4000A) 19 Standard Test and Monitoring Functions 20 Systems Check Indicator20 trip Status Indicator Lights 20 Integral Test Modes 20 Optional Functions 21 Ground Fault Monitor21 Display Module (Current Monitoring)22 Time Current Characteristic Curves23-31 Accessories 32-35 Universal Test Kit (TS-31)32-35 Ordering and Catalog Information 36-38 Electronic trip unit 36 Rating Plugs 38 Universal Test Kit (TS-31) 38 Auxiliary Power Module 38 Neutral Transformers 38UL Listings and File Numbers 391 NOTE: Information related to specific catalog numbers does not guarantee product availability.

5 Technical information may change due to product revisions. Consult Siemens sales office concerning any variation of product information contained trip Units For Siemens SB Encased Systems Breakers2 Electronic trip UnitThe Electronic trip unit is a microprocessor controlled multi-function overcurrent protective device for application withSiemens state-of-the art family of SB Encased SystemsBreakers. The adjustment flexibility provided by the trip unitallows the user to easily accommodate load changes andother protective requirements while still assuring optimumcoordination. In addition to the adjustable protection functions,the unit is designed to use field interchangeable rating ratings plugs allow the ampere rating of the breaker tobe changed to meet specific ease of installation and interchangeability in the field, thetrip unit has been designed as a plug-in unit to mount directlyinto a SB breaker sensors within the SB Breakers provide signal currentsand operating power for the trip unit .

6 Therefore, when thebreaker is closed, the trip unit requires no external connec-tions or control power to perform its protection Protection ConfigurationsTrip units are available in seven overcurrent protection configu-rations to meet specific protection requirements. Six trip unitshave Adjustable Continuous Current and Long Time protection configurations are:Protection ConfigurationIdentifierLong Time/Short Time LSLong Time/Instantaneous LILong Time/Short Time/InstantaneousLSILong Time/Short Time/Ground FaultLSGLong Time/Instantaneous/Ground Fault LIGLong/Short Time/Instantaneous/Ground Fault LSIGF ixed Long Time/Instantaneous MLIAs standard features, the trip unit has two built-in-test func-tions and a fault identification function.

7 system Check is abuilt-in-test function that continuously checks the status of themicroprocessor and protective algorithms. A green LED on the front panel blinks approximately every 3 seconds whenthe microprocessor is correctly cycling through its protectionroutines. Integral Test is a built-in-test that allows the user toexercise the trip unit electronics. LED indicators display thetesting status. trip Status is a fault identificaton function thatstores information when a fault current causes the trip unit totrip the circuit breaker . By pressing the Query button the usercan display the cause of the breaker trip by illuminating one offour LED s: OL (overload), ST (short time), SC (short circuit), orGF (ground fault).

8 Newer version trip units are equipped with aTrip Status LED Reset Button for resetting the trip optional features include:Display Module for local current monitoring (field addable)Zone Selective InterlockingCommunications for remove monitoringFull Function trip UnitNOTE: Earlier model trip units may use (lr) as the RatingPlug designator and (In) to denote (MAX Rating). The designations for the current model trip unit are shownabove. Note however, that the change in designation hasno effect on the switch settings used for selecting contin-uous, Long Time, Short Time, Instantaneous and GroundFault pickup and delay Plugln = 1000 AShortTimeDelayxlnSecs@8 x MAX RATING = @6 x ln Load MonitorAlarm Set PointsContinuous Amps%90100 Present DemandMaximum DemandIAIB607080 ICMeterSIEMENS I =% Ilg=% MAX RATINGSecs@1000A rRating PlugCurve AdjustmentsFault IndicatorsPlug-inDisplay ModuleBuilt-inTest FunctionsDescriptionFrame Sizes and Ampere Ratings, Rating Plugs.

9 And Interrupting Ratings3 Frame Sizes and Frame Ampere RatingsSiemens SB Encased Systems Breakers come in six framesizes with frame ampere ratings ranging from 400 to 5000amperes. All frames are rated for 100% continuous max ampere rating is determined by the current trans-formers within the frame. Correctly rated Electronic trip unitsare available for all SB Systems units are fully field installable by authorized personnel. Aspecial rejection scheme is built into the frames and trip unitsto prevent the installation of a trip unit into a frame for which it is not intended. The two-pin rejection scheme is shown onpage 7. The combinations of frame sizes and frame ampereratings are listed in the following PlugsField interchangeable rating plugs are used to set the effec-tive ampere rating of the circuit breaker .

10 Available rating plugs,as a function of the frame ampere ratings, are given in the following table. Note that the maximum rating plug value fora particular Electronic trip unit is equal to the frame rating; the minimum is equal to 50% of the MAX Rating. A rejectionscheme is built into the rating plugs and trip units to preventthe insertion of a rating plug into a trip unit for which it is Current SensingThe Siemens microprocessor-controlled Electronic trip Unitexecutes the overcurrent fault protection functions of SiemensSB Encased Systems Breakers . The adjustment flexibility pro-vided by the trip unit allows the user to easily accommodateload changes and other protection requirements while stillassuring optimum standard feature of the trip unit is RMS current sensing measures the true heating potential of the current waveform.