SE-325 Neutral-Grounding-Resistor Monitor Manual Rev
Contents
1. RESET SWITCH REMOTE INDICATION AND RESET EA Littelfuse DEP FA Littelfuse 525 STARTCO NGR MONITOR STARTCO NGR MONITOR sw R G D sw G R G D NOTES2 amp 3 RESISTOR FAULT INDICATOR RK 13 CONNECTION WITHOUT REMOTE INDICATION AND RESET p GROUND FAULT NOTES VEU RED INDICATOR sw 1 ALTERNATE SENSING RESISTOR TERMINAL N CONNECTION RESET SWITCH THE NEUTRAL CONNECTION IS NOT MONITORED 24 120 Vac Vde ERNE 2 K1 CLOSES ON GROUND FAULTTRIP 1 RESET CIRCUIT 3 K2 CLOSES ON REISISTOR FAULT TRIP 4 VOLTAGE BETWEEN ER TERMINALS R AND G RK 13 CONNECTION WITH REMOTE INDICATION AND RESET LIMITEDTO 100 V BY INTERNAL CLAMP CAUTION DO NOT USE K1 OR K2 INATRIP CIRCUIT FIGURE 1 Typical Application Littelfuse Page 4 STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 RESISTOR FAULT 200 o GF TRIP RES TRIP TIME 5 LEVEL VAC EA Littelfuse Oo STARTCO NGR MONITOR2. SIDE VIEW RK 13 SHOWN MOUNTED ON SE 105 SE 107 SE 325 INSTALLATION INSTRUCTIONS 1 REMOVE FOUR LEFTMOST LOWERTERMINAL BLOCK SCREWS 2 PLACE RK 13 ONTERMINAL BLOCK AND REPLACE SCREWS 3 MAKE REQUIRED CONNECTIONS TO TERMINAL BLOCK TB1 NOTES 1 DIMENSIONS IN MILLIMETRES INCHES 2 CERTIFICATIONS NOT SHOWN FIGURE 14 RK 13 Relay Interface Module Littelfuse STARTCO 3 4 ISOLATED GROUND CONNECTION The SE 325 is intended for use in installations where the NGR is connected to local ground Some installations require the NGR to be isolated from local ground See Technical Note RG 1 NGR Monitoring with Isolated Ground Beds at www littelfuse com relayscontrols 3 5 OVERHEAD LINES In overhead line applications atmospheric conditions can cause false resistor fault trips The 5 option or an SE 330 NGR Monitor is recommended for these applications 3 6 REMOTE OPERATION Terminals SW GI and RI are provided for remote LED indication and remote reset as shown in Fig 1 Remote LED s are driven in series with the front panel LED s Remove factory installed jumpers from terminals GI and RI and connect a remote kit as shown in Fig 1 Optional remote kits are shown in Figs 11 12 and 13 Standard LED indicator lamps are not compatible with the SE 325 For general purpose applications use the RK 325 Remote
3. FIGURE 11 RK 302 Remote Indication and Reset Kit a N e RESISTOR FAULT e O GROUND FAULT Q CONDUIT KNOCKOUT RK 325 RK 325 Serial No DF140309164 Revision 00 LED s 21 mA 12 Switch 50 mA 12 Vdc E A Use with SE 325 C Nus 1 800 TEC FUSE 1800 8523879 LR 53428 Made in Saskatoon Canada H 2 Fa uitteltuse 2 A V STARTCO J 3 8 0 15 i SIDE VIEW FRONT VIEW MOUNTING DETAIL NOTES 1 DIMENSIONS IN MILLIMETRES INCHES 2 NEMA 1 FIGURE 12 RK 325 Remote Indication and Reset Assembly WA Littelfuse Page 14 STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 E e RESISTOR FAULT e O GROUND FAULT O RK 325l RK 325l Serial No DF140309164 Revision 00 LED s 21 mA Q 12 GP Use with SE 325 CN 1 800 TEC FUSE 1 800 832 3873 LR 53428 Made in Saskatoon Canada 8 FA Littelfuse e V STARTCO 225 38 0 15 0 88 SIDE VIEW FRONT VIEW MOUNTING DETAIL NOTES 1 DIMENSIONS IN MILLIMETRES INCHES 2 NEMA 1 FIGURE 13 RK 325I Remote Indication Assembly Sw ki
4. Littelfuse STARTCO Resistor Fault Circuit Neutral To Ground Trip Voltage Vy 20 to 2 000 Vac Adjustable NGR Trip Resistance 0 ER 600VC or ER 5KV 2 ER 15KV or 25 6 50 with Option S Neutral To Ground DC Voltage Rejection ER 600VC or ER 5KV 1 2 V ER 15KV or ER 25KV 0 7 V 4 V with Option S Trip Resistance Accuracy 5 2 of Sensing Resistor Resistance 5 0 5 5 20 3 s with Option S Trip Mode Latching Non latching with Option N Output Relay CSA UL Contact Rating 1 mA to 4 A Resistive 240 Vac or 28 Vdc Supplemental Contact Ratings Make carry 0 2 s 10A Carry continuous 4A Break OG Hs 20 W resistive 10 W inductive L R 0 04 s 960 VA resistive 700 VA inductive PF 0 4 Subject to maximums of 4 A and 240 V ac or dc Contact Configuration N O Form A Fuse Rating Fl 4 0 A 250 Vac Time Delay Fuse Part Number Bussman MSL 4 or Littelfuse 313004 Operating Mode UV Fail Safe or SH Non Fail Safe Remote Indication j 12 Vdc GIR Current Sink 560 Internal Optional RK 13 Module Contact 0 08 A 120 V ac or dc 0 50 24 Vdc Contact Configuration N O Form
5. FIGURE 4 ER 600VC Sensing Resistor Littelfuse Page 7 STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 GASKET 120 4 4 74 4 74 ENCLOSURE TOP VIEW COVER INSIDE VIEW COVER REMOVED 120 4 4 74 ENCLOSURE TOP VIEW MOUNTING DETAIL NOTES 1 DIMENSIONS IN MILLIMETRES INCHES 2 MOUNTING SCREWS M6 OR 0 25 20 Y 25 5 ENCLOSURE SIDE VIEW FIGURE 5 SE MRE 600 Moisture Resistant Enclosure Littelfuse Page 8 STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 MOUNTING SCREWS 4 LOCATIONS NOTE 4 Q G o ER 600VC SENSING RESISTOR OK 600 FA Littelfuse STARTCO ENCLOSURE TOP VIEW COVER INSIDE VIEW COVER REMOVED ASSEMBLY INSTRUCTIONS DRILL HOLE FOR ENCLOSURE WIRE ENTRY USE LIQUID TIGHT FITTING REMOVE NYLON NUTS AND WASHERS INSERT ER 600VC INTO ENCLOSURE REPLACE NUTS AND WASHERS ATTACH GROUND WIRE FROM ENCLOSURE TO COVER AND TO ER 600VC TERMINAL G MOUNT SE MRE 600 IN PLACE USING M6 OR 0 25 20 COMPLETE OTHER WIRING AND REPLACE COVER FIGURE 6 SE MRE 600 with Installed ER 600VC Littelfuse STARTCO RATINGS MAXIMUM VOLTAGE 2 500 Vac MAXIMUM CURRENT 125 mA RESISTANCE CONTINUOUS TORQUE TERMINA
6. MOUNTING DETAIL Littelfuse STARTCO RATINGS MAXIMUM VOLTAGE 2 500 Vac MAXIMUM CURRENT 125 mA RESISTANCE THERMAL TORQUE TERMINAL N 3 LOCATIONS 10 32 INSERT 5 6 N m 50 in Ib SE 325 Neutral Grounding Resistor Monitor 381 0 21 0 15 00 por ALTERNATE NEUTRAL CONNECTION 12 0 47 NEUTRAL CONNECTION A OTHERS 9 0 N m 80 in Ib CAUTION HIGH VOLTAGE ATTENTION HAUTE EA Littelfuse STARTCO NOTE 2 AND 5 SIDE VIEW NOTES DIMENSIONS IN MILLIMETRES INCHES TERMINALBLOCK SCREWS 6 32 x 0 25 CABLE ACCESS OPENING IS 1 2 NPT USE A LIQUID TIGHT FITTING FOR CABLE ENTRY MOUNTING SCREWS M6 OR 0 25 20 THIS DEVICE CAN DISSIPATE 300 WATTS TO MINIMIZE SURFACE TEMPERATURES FOR SYSTEMS ALLOWEDTO OPERATE CONTINUOUSLY WITH A GROUND FAULT MOUNT VERTICALLY WITH R amp GTERMINALS DOWN BASE IS ELECTRICALLY CONNECTED TOTERMINAL G THROUGH JUMPER FROM TERMINAL GTO SCREW THIS CONNECTION MAY BE REMOVED FOR DIELECTRIC STRENGTH TESTING ENSURE THAT THE JUMPER IS INSTALLED AFTER TESTING CERTIFICATIONS NOT SHOWN FIGURE 8 ER 5WP Sensing Resistor TOP VIEW 316 0 12 44 Page 10 Rev 13 D 070615 0 25 20 UNC THREADED INSERT 10 32 THREADED INSERT 0 25 20 UNC STUD v FRONT VIEW MINIMUM DISTANCE a TO ADJACENT OBJECTS MINIMUM CLEARANCE FROM BASE 254 0 10 00 P
7. NOTES 1 DIMENSIONS IN MILLIMETRES INCHES 2 TERMINAL BLOCK SCREWS 6 32 x 0 25 3 MOUNTING SCREWS M4 OR 8 32 4 SHOWN WITHTERMINAL BLOCK COVER REMOVED 5 MINIMUM CLEARANCE FOR FUSE REMOVAL FIGURE 2 SE 325 Outline and Mounting Details Littelfuse STARTCO 3 2 GROUND FAULT CT Outline and mounting details for CT200 and CT200L current transformers are shown in Fig 3 Ground fault CT connections and the typical ground fault CT location are shown in Fig 1 Connect the secondary of the ground fault CT to SE 325 terminals CT1 and CT2 The CT connection to the SE 325 is not polarity sensitive Ground one side of the CT secondary For electrically noisy environments or lead BOTTOM SE 325 Neutral Grounding Resistor Monitor Page 5 Rev 13 D 070615 lengths in excess of 10 m 30 use shielded twisted pair cable NOTE The CT200 and CT200L are 600 V rated current transformers When system voltage is above 600 V ensure conductors passed through the sensor window are insulated to system voltage 44 5 MAX 1 75 NOTES 1 DIMENSIONS IN MILLIMETRES INCHES 2 MOUNTING SCREWS M4 OR 8 32 2 Ml BLACK 4 8 32 MOUNTING DETAIL PART DIMENSIONS NUMBER B C D CT200 55 9 2 20 120 7 4 75 101 6 4 00 98 3 3 87
8. 108 0 4 25 5 6 0 22 CT200L 88 9 3 50 154 0 6 06 133 4 5 25 139 7 5 50 144 5 5 69 7 1 0 28 FIGURE 3 CT200 and CT200L Current Transformers Littelfuse STARTCO 3 3 SENSING RESISTOR Outline and mounting details for ER 600VC ER 5KV ER 15KV and ER 25KV sensing resistors are shown in Figs 4 7 9 and 10 Locate the NGR and the sensing resistor near the transformer or generator When located outdoors a sensing resistor must be installed in a suitable enclosure An optional SE MRE 600 Moisture Resistant Enclosure is available for applications which may expose an ER 600VC to moisture See Figs 5 and 6 The ER 5WP shown in Fig 8 is an ER 5KV with moisture resistant terminal covers The ER 15KV and ER 25KV include moisture resistant terminal covers Use suitable water tight fittings Ground sensing resistor terminal G Pass the sensing resistor to neutral conductor and the NGR to neutral conductor through the ground fault CT window as shown in Fig 1 RATINGS MAXIMUM VOLTAGE 600Vac MAXIMUM CURRENT 30 mA RESISTANCE THERMAL 600 Vac 6 MINUTES ON 60 MINUTES OFF 420 Vac CONTINUOUS 40 0 1 57 SE 325 Neutral Grounding Resistor Monitor Page 6 Rev 13 D 070615 Separately connect sensing resistor terminal N and the NGR to the neutral to include neutral connections in the monitored loop If a ground fault in the sensing resistor conductor is unlikely a mi
9. 200 56 mm 2 27 window CT200L 89 mm 3 5 window Remote Indication and Reset RK 302 tie eie Includes two LED pilot lights a reset push button and legend plates RK 325 iiie Indication and Reset Assembly RK 325L neo Indication Assembly Relay Interface Module SE 325 Neutral Grounding Resistor Monitor Page 18 Rev 13 D 070615 6 WARRANTY The SE 325 Neutral Grounding Resistor Monitor is warranted to be free from defects in material and workmanship for a period of five years from the date of purchase Littelfuse Startco will at Littelfuse Startco s option repair replace or refund the original purchase price of an SE 325 that is determined by Littelfuse Startco to be defective if it is returned to the Startco factory freight prepaid within the warranty period This warranty does not apply to repairs required as a result of misuse negligence an accident improper installation tampering or insufficient care Littelfuse Startco does not warrant products repaired or modified by non Littelfuse Startco personnel Littelfuse STARTCO 7 TEST PROCEDURES 7 1 GROUND FAULT PERFORMANCE TEST To meet the requirements of the National Electrical Code NEC as applicable the overall ground fault protection system requires a performance test when first installed A written record of the performance test is to be retained by those in charge of the electrical installa
10. A Reset Input 24 to 120 V ac or dc Isolated PWB Conformal Coating MIL 1 46058 qualified UL QMJU2 recognized SE 325 Neutral Grounding Resistor Monitor Page 16 Rev 13 D 070615 Certification CSA Canada USA GR LR 53428 05 UL Listed LISTED Ground Fault Sensing and Relaying Equipment 9 40889 Australia N11659 Commonwealth of Pennsylvania SE 325 BOTE 1767 99 SE 325P BOTE 1797 00 FCC Fe NOTES Currents referred to primary of CT200 for prospective ground fault currents less than 4 000 A Prior to hardware revision 11 standard unit freq rep was 25 to 400 Hz and option H was 25 to 110 Hz Typical maximum CT lead resistance to meet specified trip level accuracy Applicable only on 240 Vac Supply Option E in the ordering information 2 3 a 4 2 SENSING RESISTORS ER 600VC Maximum Voltage 600 Vac Maximum Current 30 mA 20 Thermal 420 VAC isois Continuous 600 Vac 6 minutes on 60 minutes off Shipping Weight 300 g 0 7 Ib Extended Operating 55 to 60 C 67 to 1 40 F ER 5KV Maximum Voltage 2 500 Vac Maximum Current 125 mA 20 Thermal net Continuous T
11. i 3 355 6 14 00 457 0 18 00 MOUNTING DETAIL WA Littelfuse Page 11 STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 RATINGS MAXIMUM VOLTAGE 8 400 Vac MAXIMUM CURRENT 84 mA RESISTANCE THERMAL CAUTION HIGH VOLTAGE ATTENTION HAUTE 1 MINUTE ON TENSION j 120 MINUTES BA Littelfuse oro OFF STARTCO SNEUTRE QUAND UN DEFAUT M Quee EE CONTINUOUS TORQUE 7 TERMINAL N 9 0 N m 80 in Ib NOTES 2 AND 4 0 25 20 BINDING HEAD TOP eme 27 MINIMUM DISTANCE TO ADJACENT OBJECTS NOTES cues edes 1 DIMENSIONS IN MILLIMETRES INCHES NOTE 3 2 TERMINAL BLOCK SCREWS 6 32 x 0 25 MINIMUM CLEARANCE FROM BASE i 305 0 12 00 3 MOUNTING SCREWS M6 OR 0 25 20 4 USE LIQUID TIGHT FITTING FORTERMINAL BLOCK ENCLOSURE CABLE ENTRY 5 CERTIFICATIONS NOT SHOWN MOUNTING DETAIL FIGURE 9 ER 15KV Sensing Resistor WA Littelfuse Page 12 STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 RATINGS MAXIMUM VOLTAGE 14 400 Vac MAXIMUM CURRENT 144 mA M uses RESISTANCE THERMAL 14 400 Vac 1 MINUTE ON 7 1
12. is significantly reduced in a high resistance grounded system NGR selection depends on system charging current and whether the system is an alarm only or a tripping system Alarm only systems are usually restricted to system voltages up to 5 kV with NGR let through currents of 5 A or less Occasionally alarm only systems up to 15 kV and up to 10 A are used however they are not common because a ground fault on such a system tends to escalate to a phase to phase fault before the ground fault can be located and cleared System charging current is the capacitive current that flows to ground when a bolted ground fault occurs This current can be calculated or measured For small systems the magnitude of charging current can be conservatively estimated as A per 1 000 kVA on low voltage systems and 1 A per 1 000 kVA on medium voltage systems In an alarm only system or in a tripping system without selective coordination choose an NGR with a let through current larger than the system charging current and set the pick up current of ground fault devices at or below 50 of the NGR let through current In a tripping system with selective coordination use ground fault devices with a definite time characteristic to achieve time coordination Use the same pick up current for all ground fault devices this value must be larger than the charging current of the largest feeder Select an NGR with a let through current between five and ten times the pi
13. www littelfuse com relayscontrols SE 325 Neutral Grounding Resistor Monitor Page 2 Rev 13 D 070615 2 2 INDICATION AND RESET The blue POWER LED indicates that the internal power supply is on Red LED s indicate ground fault and resistor fault trips When a trip occurs the SE 325 remains latched until Reset is pressed or supply voltage is cycled Terminals are provided for remote indication and reset as shown in Fig 1 For the non latching option Option N the SE 325 resets when the fault clears 2 3 FUSING The output contact is protected by fuse F1 4 0 A time delay TABLE 1 SETTINGS FOR TYPICAL SYSTEMS System Neutral Grounding Sensing Ground Fault ResTrip Level Voltage Resistor Resistor Trip Level Let Through Resistance Model Resistance Volts Amperes Ohms Ohms Amperes Volts 480 5 55 ER 600VC 20 000 0 5 30 600 5 69 ER 600VC 20 000 0 5 40 2 400 5 277 ER 5KV 20 000 0 5 140 4 160 5 480 ER 5KV 20 000 0 5 240 480 15 18 ER 600VC 20 000 2 0 40 600 15 23 ER 600VC 20 000 2 0 50 2 400 15 92 ER 5KV 20 000 2 0 190 4 160 15 160 ER 5KV 20 000 2 0 320 7 200 15 277 15 100 000 2 0 600 14 400 15 554 15 100 000 2 0 1 100 7 200 25 166 15 100 000 4 0 700 14 400 25 332 ER 15KV 100 000 4 0 1 400 25 000 25 577 ER 25KV 100 000 4 0 2 000 Littelfuse Page 3 STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 3 INSTALLATION 3 1 SE 325 SE 32
14. 20 MINUTES 0 25 20 BINDING HEAD 3 OFF NOTES AND als 2 500 Vac CONTINUOUS TOP TORQUE TERMINAL N 9 0 N m 80 in Ib Dm E 340 0 13 38 NOTES 1 DIMENSIONS IN MILLIMETRES INCHES TERMINAL BLOCK SCREWS 6 32 x 0 25 MOUNTING SCREWS MINIMUM CLEARANCE FROM BASE M6 OR 0 25 20 508 0 20 00 USE LIQUID TIGHT FITTING FORTERMINAL BLOCK ENCLOSURE CABLE ENTRY MINIMUM DISTANCE MOUNT AS SHOWN TO ADJACENT OBJECTS WITH BASE HORIZONTAL CERTIFICATIONS NOT SHOWN MOUNTING DETAIL FIGURE 10 ER 25KV Sensing Resistor WA Littelfuse Page 13 STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 30 0 1 18 RESET PS RESISTOR FAULT GROUND FAULT LEGEND ak PLATE NOTE 2 1 222 0 87 DIA 36 6 144 7 117 LEGEND PLATES LED PILOT LIGHTS NOTES DIMENSIONS IN MILLIMETRES INCHES INDICATES CLEARANCE REQUIRED 30 0 MINIMUM 1 18 M LZ NEMA 4X CERTIFICATIONS NOT SHOWN PUSH BUTTON MOUNTING DETAIL PANELTHICKNESS 1 0TO 6 0 0 04 TO 0 24 40 0 MINIMUM
15. 5 outline and mounting details are shown in Faceplate LED s are driven in series with remote Fig 2 Typical connections are shown in Fig 1 Connect indication LED s When remote indication LED s are supply voltage to L1 and L2 For a 120 Vac supply not used terminals GI and RI must be connected for connect supply neutral to L2 For a direct current supply the face plate LED s to operate These jumpers are connect supply negative to L2 Connect chassis bonding installed at the factory terminal to ground Install the upper terminal block cover to prevent Connect contact terminals A and B as required inadvertent contact with line terminals 4160V 600V SUPPLY CT200 GROUND FAULT CT o Sia haces GROUNDING S Littelfuse SE 325 RESISTOR STARTCO NGR MONITOR A B sw Gi R G D 4 alsisisisisisis Q 6 FAULT L1 L2 5 5 B Es 20 oi amp o sr Monel nes EE GF 4 0A SH RES TRIP s 2 04 gt TIME s LEVEL VAC R 7 RESISTOR FAULT Y uv 5 6 INDICATOR 8 ER soove Littelfuse 20K STARTCO NGR MONITOR oo o eae SW GI RI R GI 2 GROUND FAULT EA Littelfuse INDICATOR e 1 SW u
16. ES Electrical specifications have been verified at a Littelfuse lab SE 325 Neutral Grounding Resistor Monitor Page 17 Rev 13 D 070615 4 3 CURRENT TRANSFORMERS CT200 Current Ratio 200 5 A Insulation 600 V Class Window Diameter 56 mm 2 2 Shipping Weight 1 kg 2 2 Ib CT200L Current Ratio 200 5 A 600 V Class Window Diameter 89 mm 3 57 Shipping Weight 1 2 kg 2 6 Ib Littelfuse STARTCO 5 ORDERING INFORMATION Option List SE 325 120 Vac Supply 2 5 Extended Resistor Trip Time E 240 Vac Supply Non Latching Operation D 120 Vac dc Supply T Extended GF TripTime List options required in order shown above Standard leave blank 5 Only Supply option available with C Tick certification SE 325P Approved by The Commonwealth of Pennsylvania for 4 800 Q NGR Requires 20 sensing resistor Sensing Resistors ER 600VG nie For system voltages up to 1 kVac 600 Optional ER 600VC moisture resistant enclosure For system voltages up to 5 9 For system voltages to 5 kVac ER ISKV nee For system voltages up to 15 kVac 25 For system voltages up to 25 kVac CT
17. Indication and Reset 2 3 3 3 1 3 2 3 3 Sensing Resistor sese 3 4 Isolated Ground Connection 15 2 2 Overhead Lines eerie 15 3 6 Remote 2 15 3 7 Ground Fault Testing sees 15 4 Technical Specifications 15 4 11 SE 325 4 3 Sensing 2 22 2 2 4 0444 16 4 3 Current Transformers 17 5 Ordering 18 6 Warranty 2 222 224 7 Test Procedures 71 Ground Fault Performance 19 7 2 Resistor Fault Tests esee 20 1 21 Open Tests tette tette 20 7 22 Voltage Testirani 20 7 3 Sensing Resistor Test 20 Appendix A SE 325 Revision History 21 SE 325 Neutral Grounding Resistor Monitor Page ii Rev 13 D 070615 LIST OF FIGURES FIGURE PAGE 1 Typical Application eene 2 SE 325 Outline and Mounting Details 3 CT200 and CT200L Current Transformers 5 4 600 Sensing Resistor eese 6 5 SE MRE 600 Moisture Resistant Enclosure 7 6 SE MRE 600 with Installed ER 600VC 8 7 ER SKV Sensing Resistor 8 ER 5WP Sensing Resistor 9 5 Sensi
18. Indication and Reset Assembly or the RK 325I Remote Indication Assembly Connect terminals SW GI and RI to remote kit terminals SW GI and CI RI For 22 mm component applications use the RK 302 Remote Indication and Reset Kit Connect terminal X2 of the red ground fault indicator to GI terminal X2 of the red resistor fault indicator to RI and connect indicator terminals to For remote reset connect the normally open push button switch across terminals and SW If indication is required from a separate voltage source or if separate ground fault and resistor fault contacts are required use an RK 13 Relay Interface Module The RK 13 mounts on the SE 325 lower terminal block and it is compatible with the RK 302 RK 325 and RK 325I See Figs 1 and 14 Contact K1 closes when the Ground Fault LED is on and contact K2 closes when the Resistor Fault LED is on 3 7 GROUND FAULT TESTING Use CT primary current injection to test the ground fault circuit Fig 15 shows test circuits using the SE 400 Ground Fault Relay Test Unit and the SE 100T Ground Fault Relay Tester The SE 400 has a programmable output of 0 5 to 9 9 A for a duration of 0 1 to 9 9 seconds The SE 100T has LO and HI outputs for 5 and 15 A resistance grounded systems A test record form is provided in Section 7 of this manual Record the test results and test dates on this form to meet the requirements of the National Electrical Code NEC Retain the form so t
19. L N 3 LOCATIONS SE 325 Neutral Grounding Resistor Monitor 381 0 210 15 00 0 83 ALTERNATE NEUTRAL CONNECTION 12 0 0 47 NEUTRAL CONNECTION 10 32 INSERT 5 6 N m 50 in Ib OTHERS 42 2520 9 0 N m 80 in Ib o SISTOR FA Littelfuse STARTCO Page 9 Rev 13 D 070615 0 25 20 UNC THREADED INSERT 10 32 THREADED NOTES 5 amp 6 SIDE VIEW NOTES DIMENSIONS IN MILLIMETRES INCHES TERMINALBLOCK SCREWS 6 32 x 0 25 MOUNTING SCREWS M6 OR 0 25 20 THIS DEVICE CAN DISSIPATE 300 WATTS TO MINIMIZE SURFACE TEMPERATURES FOR SYSTEMS ALLOWED TO OPERATE CONTINUOUSLY WITH A GROUND FAULT MOUNT VERTICALLY WITH R amp GTERMINALS DOWN ON REVISION 2 UNITS BASE IS ELECTRICALLY CONNECTEDTO TERMINAL G THROUGH JUMPER FROM TERMINAL G TO SCREW THIS CONNECTION MAY BE REMOVED FOR DIELECTRIC STRENGTH TESTING ENSURE THAT THE JUMPER IS INSTALLED AFTER TESTING ON REVISION 0 amp 1 UNITS SCREW IS NOT PRESENT AND BASE IS ELECTRICALLY CONNECTED TO TERMINAL G CERTIFICATIONS NOT SHOWN FIGURE 7 ER 5KV Sensing Resistor TOP VIEW 316 0 12 44 INSERT 0 25 20 UNC STUD s FRONT VIEW MINIMUM DISTANCE J TO ADJACENT OBJECTS MINIMUM CLEARANCE FROM BASE 254 0 10 00 3 355 6 14 00 457 0 18 00
20. WA Littelfuse STARTCO 3714 Kinnear Place Saskatoon SK Canada 57 0 6 Ph 306 373 5505 306 374 2245 www littelfuse com relayscontrols SE 325 MANUAL NEUTRAL GROUNDING RESISTOR MONITOR REVISION 13 D 070615 gt 191 S a L2 GROUND RESET RESISTOR FAULT FAULT 200 1 0 i000 2 0 20 400 er EGET 4 0A SH RES TRIP LEVEL VAC O 5 A UV 20K Q rower i FA Littelfuse SE 325 STARTCO NGR MONITOR SW GI GF TRIP TIME s eSISSSSISS c gt Copyright 2015 by Littelfuse Startco All rights reserved Document Number PM 1220 EN Printed in Canada Littelfuse Page i STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 This page intentionally left blank Littelfuse STARTCO TABLE OF CONTENTS SECTION PAGE 1 General cS eee Deer tp bees 1 1 1 Modem Resistance Grounded Systems 1 1 2 SE 325 Monitoring 2 1 2 Operations nete Rees 1 Reo ere 1 2 1 1 GF Trip Time 212 GE is acetone 2 1 3 Mode 2 14 RES iiec ei titer iere pe canes 2 1 5 RES Trip reti 2 2
21. ck up current of the ground fault devices Do not use a grounding transformer with a low voltage resistor e The combined cost of a transformer and a low voltage resistor is more than the cost of a resistor rated for line to neutral voltage transformer saturated by a ground fault through a rectifier make ground fault protection inoperative e Transformer inrush current up to twelve times rated current can cause a ground fault voltage larger than expected e A parallel transformer winding makes it difficult to monitor NGR continuity e transformer can provide the inductance necessary to cause ferroresonance if the NGR opens SE 325 Neutral Grounding Resistor Monitor Page 1 Rev 13 D 070615 Following these guidelines will reduce the flash hazard reduce point of fault damage achieve reliable ground fault protection and ensure a stable system not subject to ferroresonance 1 2 SE 325 MONITORING The SE 325 is a neutral grounding resistor monitor for resistance grounded systems up to 25 kVac It measures current in a transformer or generator neutral neutral to ground voltage and continuity of the neutral grounding resistor The SE 325 coordinates these three measurements to detect a failed NGR or a ground fault and provides one output contact for shunt or undervoltage operation in a main breaker trip circuit Trips are latched and indicated by LED s Ground fault current is sensed by a CT200 window typ
22. e current transformer Either CT input can be grounded to meet electrical codes A trip level of 0 5 2 0 or 4 0 A is switch selectable for use with a 5 15 or 25 A grounding resistor Trip time is adjustable from 0 1 to 2 0 seconds Neutral to ground voltage and continuity of the neutral grounding resistor are continuously measured through an ER series external sensing resistor connected to the neutral A resistor fault will be detected if ground fault current is not detected and neutral to ground voltage exceeds the trip level setting or if NGR resistance exceeds the trip resistance A resistor fault hold off circuit prevents nuisance trips in alarm only systems For additional information on neutral grounding resistor monitoring see Monitoring Neutral Grounding Resistors An Update at www littelfuse com relayscontrols 2 OPERATION 2 1 SETTINGS 2 1 1 GF TRIP TIME Ground fault trip time is adjustable from 0 1 to 2 0 seconds Time coordinated ground fault protection requires this setting to be longer than the trip times of downstream ground fault devices For the extended ground fault trip time option Option T trip time is adjustable from 0 1 to 5 0 seconds 2 1 2 GF The ground fault circuit trip level is 0 5 2 0 or 4 0A when current is sensed with a CT200 current transformer These levels are appropriate for use with 5 15 or 25 A grounding resistors when a ground fault trip level less than 20 of the grounding
23. hat the test data can be made available to the authority having jurisdiction SE 325 Neutral Grounding Resistor Monitor Page 15 Rev 13 D 070615 4 TECHNICAL SPECIFICATIONS 4 1 SE 325 Supply 10 120 240 10 45 50 60 Hz 5 W 120 Vdc 40 8 10 VA 120 Vac 10 45 50 60 Hz NOTE Voltage between supply terminals L1 L2 and ground terminal G must not exceed 300 Vac continuous or 1 250 Vac under transient conditions Dimensions Height seen 150 mm 5 9 109 mm 4 3 D ptli enit 100 mm 4 0 Shipping Weight 1 kg 2 2 Ib Environment Operating Temperature 40 to 60 C 40 to 140 F Storage Temperature 55 to 80 C 67 to 176 F Humidity 85 Non Condensing Ground Fault Circuit CT R3 nee ette 200 5 CT Input Burden 0 02 Q Trip Level 0 5 2 0 or 4 0 A Frequency Response 25 to 110 Hz Trip Time oe 0 1 to 2 0 s 0 1 to 5 0 s with Option T Thermal Withstand 200 A Continuous 2 500 A for 2 s Trip Level Accuracy 10 20 CT Lead Resistance Limit 0 5 A Trip Level 20 2 A Trip Level 50 4 A Trip Level 50 Trip Time Accuracy 1096 Trip Mode Latching Non latching with Option N
24. move the test resistor and wait 5 seconds 20 seconds with Option S PASS The SE 325 should trip on RESISTOR FAULT Connect the 100 kQ resistor to R and G terminals Set the RES switch to 100K Press RESET The RESISTOR FAULT LED should be off Remove the test resistor and wait 5 seconds 20 seconds with Option S PASS The SE 325 should trip on RESISTOR FAULT To test the connected wiring sensing resistor and NGR e Reconnect SE 325 R and G connections e Set the RES switch to match sensing resistor e Press RESET PASS The RESISTOR FAULT LED should be off 7 2 2 VOLTAGE TEST Test Equipment 0 to 120 Vac voltage source and multimeter SE 325 Neutral Grounding Resistor Monitor NOTE Also use an isolation transformer if the test voltage source does not provide dc continuity for the SE 325 resistance measurement circuit NOTE Applying the test voltage to the R and G terminals will damage the SE 325 and the ER sensing resistor The RES TRIP LEVEL is the trip voltage at terminal N not terminal R Procedure e Check the ER sensing resistor connection to the SE 325 e Disconnect the wire from sensing resistor terminal N A resistor fault trip will occur e Set the voltage source to 0 V Connect the voltage source between sensing resistor N and G terminals Set the RES TRIP LEVEL VAC to 20 Press RESET The RESISTOR FAULT LED should be off Increase the test voltage to 25 Vac for 20 senso
25. ng Resistor 10 ER 25KV Sensing Resistor 11 RK 302 Remote Indication and Reset Kit 13 12 RK 325 Remote Indication and Reset Assembly 13 13 RK 325I Remote Indication Assembly 14 14 RK 13 Relay Interface Module 14 15 Ground Fault Test Circuits esses 19 LIST OF TABLES TABLE PAGE 1 Settings For Typical Systems 2 Ground Fault Test Record sess DISCLAIMER Specifications are subject to change without notice Littelfuse Startco is not liable for contingent consequential damages or for expenses sustained as a result of incorrect application incorrect adjustment or a malfunction WA Littelfuse Page ii STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 This page intentionally left blank Littelfuse STARTCO 1 GENERAL 1 1 MODERN RESISTANCE GROUNDED SYSTEMS A high resistance grounded system uses a neutral grounding resistor NGR with a low let through current to limit ground fault current This is an improvement over low resistance or solidly grounded systems because in those systems a ground fault flash hazard exists and a ground fault can result in substantial point of fault damage High resistance grounding eliminates these problems and modern ground fault protection operates reliably at these levels Furthermore the probability of an arc flash incident
26. nimal loss of protection will result if it does not pass through the ground fault CT window CAUTION Voltage at terminal N rises to line to neutral voltage when a ground fault occurs The same clearances are required for sensing resistors as for NGR s NOTE The neutral to sensing resistor connection is not a neutral conductor as defined in Canadian Electrical Code Section 10 1108 and National Electrical Code Section 250 36 B It is not required to be 8 AWG 8 36 mm or larger Since current through this conductor is always less than 150 mA a 14 AWG 2 08 mm conductor insulated to the system voltage is sufficient 9 ER 600VC SENSING RESISTOR SENSING RESISTI Serial No GC1403 600 VAC FA Littelfuse STARTCO of 83 fie 4 5 0 18 DIA C BORE 10 0 0 39 DIA 3 2 0 13 DEEP FRONT SIDE NOTES 1 DIMENSIONS IN MILLIMETRES INCHES 2 TERMINALBLOCK SCREWS 6 32 x 0 25 3 MOUNTING SCREWS M4 OR 8 32 MOUNTING DETAIL 4 ON REVISION 2 UNITS ENCLOSURE IS ELECTRICALLY CONNECTEDTO TERMINAL G THROUGH JUMPER FROM TERMINAL G SCREW THIS CONNECTION MAY BE REMOVED FOR DIELECTRIC STRENGTH TESTING ENSURETHAT THE JUMPER IS INSTALLED AFTER TESTING ON REVISION 1 UNITS COSCREW IS NOT PRESENT AND ENCLOSURE IS ELECTRICALLY CONNECTED TO TERMINAL G
27. orque Terminal N 10 32 Insert 5 6 N m 50 in Ib 9 0 N m 80 in Ib Shipping Weight 5 0 kg 11 Ib Littelfuse STARTCO ER 5 WP Maximum Voltage 2 500 Vac Maximum Current 125 mA 20 Thermal Continuous Torque Terminal N 10 32 Insert 5 6 N m 50 in Ib Others sess 9 0 N m 80 in Ib Shipping Weight 5 0 kg 11 Ib ER 15KV Maximum Voltage 8 400 Vac Maximum Current 84 mA Resistance 100 kQ Thermal 8 400 minute on 120 minutes off 1 900 Continuous Torque Terminal N 9 0 N m 80 in Ib Shipping Weight 5 0 kg 11 Ib ER 25KV Maximum Voltage 14 400 Vac Maximum Current 144 mA 100 Thermal 14 400 1 minute on 120 minutes off 2 300 Continuous Torque Terminal N 9 0 N m 80 in Ib Shipping Weight 20 kg 44 Ib CSA Canada and USA LR 53428 US UL Listed Fault Sensing and Relaying Equipment 4FX9 40889 CE European Union NOT
28. resistor let through current is desired See Table 1 For other applications the trip level of the ground fault circuit is 0 25 1 0 or 2 096 of the primary rating of the 5 A secondary current transformer Littelfuse STARTCO 2 1 3 MODE In the shunt trip mode SH the output relay energizes and its contact closes if a resistor fault or ground fault trip occurs The shunt trip mode is not fail safe because shunt trip devices do not operate if supply voltage fails In the undervoltage mode UV the output relay energizes and its contact closes if the resistor fault and ground fault circuits are not tripped The undervoltage mode is referred to as fail safe because undervoltage devices release if supply voltage fails 2 1 4 RES This switch setting must correspond to the resistance of the external sensing resistor For the ER 600VC and ER 5KV select 20K For the ER 15KV and ER 25KV select 100K 2 1 5 RES TRIP LEVEL Neutral to ground trip voltage is adjustable from 20 to 400 Vac with a 20 kO sensing resistor and 100 to 2 000 Vac with a 100 kQ sensing resistor To prevent false resistor fault trips the RES TRIP LEVEL should be set higher than the voltage across the neutral grounding resistor when neutral to ground current is equal to the operating value of the ground fault circuit Typical values for 5 15 and 25 A tripping systems are shown in Table 1 For other systems refer to the NGR Monitor Set Point Assistant at
29. rovides a test current of 0 65 or 2 75 A for testing 0 5 and 2 0 A trip levels Inject the test current through the current transformer window for at least 2 5 seconds Verify that the circuit under test has reacted properly Correct any problems and re test until the proper reaction is verified e Record the date and the results of the test on the attached test record form SE 325 Neutral Grounding Resistor Monitor Page 19 Rev 13 D 070615 a USING SE 400 CT200 GROUND FAULT CT NEUTRAL GROUNDING RESISTOR b USING SE 100T CT200 o CT2 GROUND FAULT CT IGI lo L1 NEUTRAL 5 325 GROUNDING RESISTOR SE 100T FIGURE 15 Ground Fault Test Circuits TABLE 2 GROUND FAULT TEST RECORD DATE TEST RESULTS Retain this record for the authority having jurisdiction Littelfuse STARTCO 7 2 RESISTOR FAULT TESTS Perform tests with system de energized and supply voltage applied to the SE 325 7 2 1 OPEN TEST Test Equipment 20 kQ and 100 4 watt 1 resistors included with SE 325 Procedure Remove connections to SE 325 R and G terminals Connect the 20 kQ resistor to R and G terminals Set the RES switch to 20K Press RESET The RESISTOR FAULT LED should be off Re
30. rs or Page 20 Rev 13 D 070615 120 Vac for 100 kQ sensors and wait 5 seconds 20 seconds with Option S PASS The SE 325 should trip on RESISTOR FAULT 7 3 SENSING RESISTOR TEST Test Equipment Multimeter Procedure e Disconnect the sensing resistor e Measure the resistance between sensing resistor terminals RandN PASS Resistance should be between 19 6 and 20 4 kQ for 20 kQ sensing resistors Resistance should be between 98 and 102 kQ for 100 kQ sensing resistors e Measure the resistance between sensing resistor terminals R and G in both directions PASS Resistance should be greater than 10 MQ in both directions FA Littelfuse Page 21 STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 APPENDIX A SE 325 REVISION HISTORY MANUAL PRODUCT REVISION RELEASE DATE MANUAL REVISION REVISION NUMBER ON PRODUCT LABEL July 6 2015 13 D 070615 13 September 23 2014 13 C 092314 August 27 2013 13 B 082713 12 August 13 2013 13 A 081313 MANUAL REVISION HISTORY REVISION 13 D 070615 SECTION 5 FCC certification added Updated Fuse F1 part number APPENDIX A Revision history updated REVISION 13 C 092314 SECTION 3 Updated Figs 4 7 8 9 10 12 and 13 SECTION 4 Updated RK 13 contact ratings APPENDIX A Revision history updated REVISION 13 B 082713 SECTION 3 Updated Figures 7 8 9 and 10 REVISION 13 A 081313 SECTION 3 Updated Figure 11 APPENDIX A Added Revision Hi
31. story PRODUCT REVISION HISTORY HARDWARE REVISION 13 Minor hardware change HARDWARE REVISION 12 Component change to improve stability of ground fault detection circuit WA Littelfuse jan STARTCO SE 325 Neutral Grounding Resistor Monitor Rev 13 D 070615 This page intentionally left blank
32. tion in order to make it available to the authority having jurisdiction A test record form is provided for recording the date and the final results of the performance tests The following ground fault system tests are to be conducted by qualified personnel a Evaluate the interconnected system in accordance with the overall equipment manufacturer s detailed instructions b Verify proper location of the ground fault current transformer Ensure the cables pass through the ground fault current transformer window This check can be done visually with knowledge of the circuit The connection of the current transformer secondary to the SE 325 is not polarity sensitive c Verify that the system is correctly grounded and that alternate ground paths do not exist that bypass the current transformer High voltage testers and resistance bridges can be used to determine the existence of alternate ground paths d Verify proper reaction of the circuit interrupting device in response to a simulated or controlled ground fault current To simulate ground fault current use CT primary current injection Fig 15a shows a test circuit using an SE 400 Ground Fault Relay Test Unit The SE 400 has a programmable output of 0 5 to 9 9 A for a duration of 0 1 to 9 9 seconds Set the test current to 0 6 2 3 or 4 6 A for SE 325 units set at 0 5 2 0 or 4 0 A respectively Fig 15b shows a test circuit using an SE 100T Ground Fault Relay Tester The SE 100T p
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