epo dlva 208

SE-325 MANUAL

NEUTRAL-GROUNDING-RESISTOR MONITOR

NOVEMBER 29, 2005

REVISION 9

F 1

R E S E T

P O W E R

G R O U N D

F A U L T

G F T R I P

T I M E ( s )

R E S I S TO R

F A U L T

R E S T R I P

L E V E L ( V A C )

C T 1 C T 2 A B

R IG IS W

L 1

R

L 2

G

STARTCOE N G I N E E R I N G L T D . N G R M O N I T O R

SE-325

M O D E R E SG F

2 0 4 0 0

2 0 0

0 . 1 2 . 0

1 . 0

4 . 0 A

2 . 0 A

0 . 5 A

S H

U V 2 0 K

Copyright 2005 by Startco Engineering Ltd.

All rights reserved.

Publication: SE-325-MDocument: S95-C325-00000Printed in Canada.

Blank Page

Startco Engineering Ltd. Page iSE-325 Neutral-Grounding-Resistor Monitor Rev. 6

Pub. SE-325-M, November 29, 2005.

TABLE OF CONTENTSPAGE

Table of Contents .................................................................... iList of Figures.......................................................................... iList of Tables ........................................................................... i

1. General .........................................................................11.1 Modern Resistance-Grounded Systems .......................11.2 SE-325 NGR Monitoring..............................................1

2. Operation......................................................................12.1 Settings ..........................................................................1

2.1.1 GF Trip Time...................................................12.1.2 GF ....................................................................12.1.3 Mode ................................................................22.1.4 RES ..................................................................22.1.5 RES Trip Level................................................2

2.2 Indication and Reset......................................................22.3 Fusing ............................................................................2

3. Installation....................................................................33.1 SE-325 ..........................................................................33.2 Ground-Fault CT...........................................................53.3 Sensing Resistor ............................................................63.4 Isolated-Ground Connection.......................................123.5 Overhead Lines ...........................................................123.6 Remote Operation .......................................................123.7 Ground-Fault Testing..................................................12

4. Technical Specifications ...........................................124.1 SE-325 ........................................................................124.2 Sensing Resistors.........................................................134.3 Current Transformer....................................................13

5. Ordering Information...............................................14

6. Warranty ....................................................................14

7. Test Procedures .........................................................157.1 Ground-Fault Performance Test .................................157.2 Resistor-Fault Tests.....................................................16

7.2.1 Open Test ..........................................................167.2.2 Voltage Test ......................................................16

7.3 Sensing-Resistor Test..................................................16

LIST OF FIGURESFIGURE PAGE

1 Typical Application ...................................................... 32 SE-325 Outline and Mounting Details......................... 43. Current Transformers.................................................... 54 ER-600VC Sensing Resistor ........................................ 65 ER-5KV Sensing Resistor ............................................ 76 ER-15KV Sensing Resistor .......................................... 87 ER-25KV Sensing Resistor .......................................... 98 RK-302 Remote Indication and Reset ....................... 109 RK-325 Remote Indication-and-Reset Assembly ..... 1010 RK-325I Remote Indication Assembly...................... 1111 RK-13 Relay Interface Module .................................. 1112 Ground-Fault-Test Circuits......................................... 15

LIST OF TABLESTABLE PAGE

1 Settings For Typical Systems ....................................... 22 Ground-Fault-Test Record.......................................... 15

DISCLAIMER

Specifications are subject to change without notice. StartcoEngineering Ltd. is not liable for contingent or consequentialdamages, or for expenses sustained as a result of incorrectapplication, incorrect adjustment, or a malfunction.

Blank Page

Startco Engineering Ltd. Page 1SE-325 Neutral-Grounding-Resistor Monitor Rev. 7

Pub. SE-325-M, November 29, 2005

1. GENERAL

1.1 MODERN RESISTANCE-GROUNDED SYSTEMSIn the past, a resistance-grounded system often used a

neutral-grounding resistor (NGR) with a high let-throughcurrent. In a system with a high let-through current,point-of-fault damage and flash hazard are significantproblems. These problems can be eliminated with alow-let-through-current NGR. Modern ground-faultprotection is designed to operate at these levels.

NGR selection depends on whether the system is analarm-only or a tripping system. Alarm-only systems areusually restricted to system voltages up to 5 kV withNGR 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 onsuch a system tends to escalate to a phase-to-phase faultbefore the ground fault can be located and cleared.

In an alarm-only system or in a tripping system withoutselective coordination, choose an NGR with a let-throughcurrent larger than the system charging current. Systemcharging current is the capacitive current that flows toground when a bolted ground fault occurs. Themagnitude of charging current is typically ½ A per1,000 kVA on low-voltage systems and 1 A per1,000 kVA on medium-voltage systems. Consequently,there is flexibility in choosing low-current NGR’s forthese systems. The pick-up current of ground-faultdevices is usually set at or below 50% of the NGR let-through current in an alarm-only system and at or below20% in a tripping system.

In a tripping system with selective coordination, useground-fault devices with a definite-time characteristic toachieve time coordination. Use the same pick-up currentfor all ground-fault devices—this value must be largerthan the charging current of the largest feeder. Select anNGR with a let-through current between five and tentimes the pick-up current of the ground-fault devices.

Do not use a grounding transformer with a low-voltageresistor:• The combined cost of a transformer and a low-

voltage resistor is more than the cost of a resistorrated for line-to-neutral voltage.

• A transformer saturated by a ground fault through arectifier can make ground-fault protectioninoperative.

• Transformer inrush current up to twelve times ratedcurrent can cause a ground-fault voltage larger thanexpected.

• A parallel transformer winding makes it difficult tomonitor NGR continuity.

• A transformer can provide the inductance necessaryto cause ferroresonance if the NGR opens.

Following these guidelines will minimize the flashhazard, minimize point-of-fault damage, achieve reliable

ground-fault protection, and ensure a stable system notsubject to ferroresonance.

1.2 SE-325 NGR MONITORINGThe SE-325 is a neutral-grounding-resistor monitor for

resistance-grounded systems up to 25 kVac. It measurescurrent in a transformer or generator neutral, neutral-to-ground voltage, and continuity of the neutral-groundingresistor. The SE-325 coordinates these three measurementsto detect a failed NGR or a ground fault and provides oneoutput contact for shunt or undervoltage operation in amain-breaker trip circuit. Trips are latched and indicated byLED’s.

Ground-fault current is sensed by a CT200 window-typecurrent transformer. Either CT input can be grounded tomeet electrical codes. A trip level of 0.5, 2.0, or 4.0 A isswitch selectable for use with a 5-, 15-, or 25-A groundingresistor. 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 anER-series external sensing resistor connected to the neutral.A resistor fault will be detected if ground-fault current is notdetected and neutral-to-ground voltage exceeds the trip-levelsetting, or if NGR resistance exceeds the trip resistance. Aresistor-fault hold-off circuit prevents nuisance trips inalarm-only systems.

For additional information on neutral-grounding-resistormonitoring, see “Monitoring Neutral-Grounding Resistors”at www.startco.ca.

2. OPERATION

2.1 SETTINGS2.1.1 GF TRIP TIME

Ground-fault trip time is adjustable from 0.1 to 2.0seconds. Time-coordinated ground-fault protection requiresthis setting to be longer than the trip times of downstreamground-fault devices.

For the extended trip-time option, trip time is adjustablefrom 0.1 to 5.0 seconds.

2.1.2 GFThe ground-fault-circuit trip level is 0.5, 2.0, or 4.0 A

when current is sensed with a CT200 current transformer.Since the ground-fault-circuit trip level should not be greaterthan 20% of the grounding resistor let-through current, theselevels are appropriate for use with 5-, 15-, or 25-Agrounding resistors. See Table 1. For other applications, thetrip level of the ground-fault circuit is 0.25, 1.0, or 2.0% ofthe primary rating of the 5-A-secondary current transformer.



2.1.3 MODEIn the shunt-trip mode (SH), the output relay energizes

and its contact closes if a resistor-fault or ground-fault tripoccurs. 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 relayenergizes and its contact closes if the resistor-fault andground-fault circuits are not tripped. The undervoltagemode is referred to as fail-safe because undervoltage devicesrelease if supply voltage fails.

2.1.4 RESThis switch setting must correspond to the resistance of

the external sensing resistor. For the ER-600VC andER-5KV, select 20K. For the ER-15KV and ER-25KV,select 100K.

2.1.5 RES TRIP LEVELNeutral-to-ground trip voltage is adjustable from 20 to

400 Vac with a 20-kΩ sensing resistor, and 100 to2,000 Vac with a 100-kΩ sensing resistor. To prevent falseresistor-fault trips, the RES TRIP LEVEL should be sethigher than the voltage across the neutral-grounding resistorwhen neutral-to-ground current is equal to the operatingvalue of the ground-fault circuit. See Table 1.

2.2 INDICATION AND RESETThe green 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 latcheduntil the reset switch is pressed or supply voltage is cycled.Terminals are provided for remote indication and reset asshown in Fig. 1.

For the non-latching option, the SE-325 resets when thefault clears.

2.3 FUSINGThe output contact is protected by fuse F1 (4.0 A, time

delay).

TABLE 1. SETTINGS FOR TYPICAL SYSTEMSSystemVoltage

Neutral-GroundingResistor

SensingResistor

Ground-FaultTrip Level ResTrip Level

(Volts)Let Through(Amperes)

Resistance(Ohms)

Model Resistance(Ohms) (Amperes) (Volts)

480600

2,4004,160

480600

2,4004,1607,200

14,4007,200

14,40025,000

5555

151515151515252525

5569

277480182392

160277554166332577

ER-600VCER-600VCER-5KVER-5KVER-600VCER-600VCER-5KVER-5KVER-15KVER-15KVER-15KVER-15KVER-25KV

20,00020,00020,00020,00020,00020,00020,00020,000

100,000100,000100,000100,000100,000

0.50.50.50.52.02.02.02.02.02.04.04.04.0

3040

1402404050

190320600

1,100700

1,4002,000



3. INSTALLATION3.1 SE-325

SE-325 outline and mounting details are shown inFig. 2. Typical connections are shown in Fig. 1. Connectsupply voltage to L1 and L2. For a 120-Vac supply,connect supply neutral to L2. For a direct-current supply,connect supply negative to L2. Connect chassis-bondingterminal to ground.

Connect contact terminals A and B as required.

Face-plate LED's are driven in series with remote-indication LED's. When remote-indication LED’s are notused, terminals GI, +, and RI must be connected for theface-plate LED’s to operate. These jumpers are installedat the factory.

Install the upper terminal-block cover to preventinadvertent contact with line terminals.

N

R

G

ER-600VC

SENS ING RES ISTOR

20 K

6 0 0 VA C M A X

STARTCOE N G I N E E R I N G L T D .

M A D E I N S A S K A T O O N , C A N A D A

600 V4160 V

SUPPLY

NEUTRAL

GROUNDING

RESISTOR

CT200

GROUND-FAULT CT

UV

120 VAC

L N

LOAD

RESISTOR-FAULT

INDICATOR

GROUND-FAULT

INDICATOR

RESET SWITCH

REMOTE INDICATION AND RESET

RED

RED

F 1

R E S E T

P O W E R

G R O U N D

F A U L T

G F T R I P

T I M E ( s )

R E S I S TO R

F A U L T

R E S T R I P

L E V E L ( V A C )

C T 1 C T 2 A B

R IG IS W

L 1

R

L 2

G


SE-325

M O D E R E SG F

2 0 4 0 0

2 0 0

0 . 1 2 . 0

1 . 0

4 . 0 A

2 . 0 A

0 . 5 A

S H

U V 2 0 K

R IG IS W R G


SE-325

ER

RS1

RS2

CGI

GRI

+SW K1 K2

SW CI/GI + GI/RI

TB1

RESISTOR-FAULTINDICATOR

GROUND-FAULTINDICATOR

RESET SWITCH

RED

RED

RK-13 CONNECTION WITH REMOTE INDICATION AND RESET

ALTERNATERESET CIRCUIT

24-120 Vac/Vdc

RK-13 CONNECTION WITHOUT REMOTE INDICATION OR RESET

K1 K2 RI

+

GI

SW

R IG IS W R G


SE-325

RI

GI

SW

ER

RS1

RS2

CGI

GRI

+SW K1 K2

SW CI/GI + GI/RI

TB1

K1 K2

R IG IS W R G


SE-325

ER

NOTES:

1. ALTERNATE SENSING-RESISTOR TERMINAL-N CONNECTION.

2. ALTERNATE CT LOCATION.

3. K1 CLOSES ON GROUND-FAULT TRIP

4. K2 CLOSES ON RESISTOR-FAULT TRIP

5. VOLTAGE BETWEEN ER TERMINALS R AND GLIMITED TO 100 V BY INTERNAL CLAMP.

CAUTION: DO NOT USE K1 OR K2 IN A TRIP CIRCUIT.

NOTE 1

NOTE 2

NOTES 3 & 4

NOTE 5

FIGURE 1. Typical Application



NOTES:

1.

2.

3.

4.

5.

DIMENSIONS IN MILLIMETRES (INCHES).

TERMINAL-BLOCK SCREWS: 6-32 x 0.25.

MOUNTING SCREWS: M4 OR 8-32.

SHOWN WITH TERMINAL-BLOCK COVER REMOVED.

MINIMUM CLEARANCE FOR FUSE REMOVAL.

109.0

(4.29)

(3.50)

(5.5

0)

(5.9

0)

88.9

13

9.7

15

0.0

4 . 8 (0 .19 ) D IA

100.0

(3.93)

(3.06)

77.8

F 1

R E S E T

P O W E R

G R O U N D

F A U L T

G F T R I P

T I M E ( s )

R E S I S TO R

F A U L T

R E S T R I P

L E V E L ( V A C )

C T 1 C T 2 A B

R IG IS W

L 1

R

L 2

G


SE-325

M O D E R E SG F

2 0 4 0 0

2 0 0

0 . 1 2 . 0

1 . 0

4 . 0 A

2 . 0 A

0 . 5 A

S H

U V 2 0 K

43

.5

(1.7

1)

NOTE 5

NOTE 4

FIGURE 2. SE-325 Outline and Mounting Details.



3.2 GROUND-FAULT CTOutline and mounting details for CT200 and CT200L

current transformers are shown in Fig. 3. Ground-fault-CTconnections and the preferred ground-fault-CT location areshown in Fig. 1. If a ground fault in the NGR is unlikely, aminimal loss of protection will result if the ground-fault CTmonitors the NGR connection to ground rather than itsconnection to the neutral. This alternate CT location isshown in Fig. 1.

Connect the secondary of the ground-fault CT to SE-325terminals CT1 and CT2. The CT connection to the SE-325is not polarity sensitive. Ground one side of the CTsecondary. For electrically noisy environments or leadlengths in excess of 10 m (30 ft), use shielded, twisted-paircable.

D

A

E

B

FRONT

9.4

(0.37)

F

BOTTOM

B

C

TAP M4 OR 8-32

22.2

(0.8

7)

44.5

(1.7

5)

MOUNTING DETAIL

SIDE

WHITE

BLACK

X1 X2

44.5 MAX

(1.75)NOTES:

1. DIMENSIONS INMILLIMETRES (INCHES).

2. MOUNTING SCREWS:M4 OR 8-32.

PARTNUMBER

CT200

CT200L

A B C D E F

55.9 (2.20)

88.9 (3.50)

120.7 (4.75)

154.0 (6.06)

101.6 (4.00)

133.4 (5.25)

98.3 (3.87)

139.7 (5.50)

108.0 (4.25)

144.5 (5.69)

5.6 (0.22)

7.1 (0.28)

DIMENSIONS

FIGURE 3. Current Transformers.



3.3 SENSING RESISTOROutline and mounting details for ER-600VC, ER-5KV,

ER-15KV, and ER-25KV sensing resistors are shown inFigs. 4, 5, 6, and 7. Locate the NGR and the sensingresistor near the transformer or generator. Ground sensing-resistor terminal G. Pass the sensing-resistor-to-neutralconductor and the NGR-to-neutral conductor through theground-fault-CT window as shown in Fig. 1. Separatelyconnect sensing-resistor terminal N and the NGR to theneutral to include neutral connections in the monitoredloop. If a ground fault in the sensing-resistor conductor isunlikely, a minimal loss of protection will result if it doesnot pass through the ground-fault-CT window.

CAUTION: Voltage at terminal N rises to line-to-neutralvoltage when a ground fault occurs. The same clearancesare required for sensing resistors as for NGR's.

NOTE: The neutral-to-sensing-resistor connection is nota neutral conductor as defined in Canadian ElectricalCode Section 10-1108 and National Electrical CodeSection 250.36(B). It is not required to be 8 AWG orlarger. Since current through this conductor is alwaysless than 150 mA, a 14 AWG conductor insulated to thesystem voltage is more than sufficient.

MOUNTING DETAIL

105.0

8.0

89.0

8.0

40.0

19.0 10.510.5

(4.1

3)

(0.3

1)

(3.5

0)

(0.3

1)

(1.57)

(0.75) (0.41)(0.41)

NOTE 3

SIDE

41.5

22.2

(1.63)

(0.87)

FRONT

NOTES:

1.

2.

3.

4.

DIMENSIONS IN MILLIMETRES (INCHES).

TERMINAL-BLOCK SCREWS: 6-32 x 0.25.

MOUNTING SCREWS: M4 OR 8-32.

ENCLOSURE IS ELECTRICALLY CONNECTED TO TERMINAL G.

4.5 (0.18) DIA

C'BORE 10.0 (0.39) DIA

3.2 (0.13) DEEP

40.0

105.0

(1.57)

(4.1

3)

N

R

G

ER-600VC

SE NS ING RES ISTOR

20 K

6 0 0 VA C M A X



RATINGS:MAXIMUM VOLTAGE . 600 VacMAXIMUM CURRENT . 30 mA

RESISTANCE . . . . . . . 20 kTHERMAL:

420 Vac . . . . . . . . . . CONTINUOUS600 Vac . . . . . . . . . . 6 MINUTES ON,

60 MINUTES OFF

FIGURE 4. ER-600VC Sensing Resistor



355.6

254.0

127.0

457.0

50.7(14.00)

(10.0

0)

(5.0

0)

(18.00)

(2.00)

MINIMUM DISTANCETO ADJACENT OBJECTS

MOUNTING DETAIL

NOTE 3

NOTES:

1.

2.

3.

4.

DIMENSIONS IN MILLIMETRES(INCHES).

TERMINAL-BLOCK SCREWS:6-32 x 0.25.

MOUNTING SCREWS:M6 OR 0.25-20.

THIS DEVICE CAN DISSIPATE300 WATTS. TO MINIMIZESURFACE TEMPERATURESFOR SYSTEMS ALLOWED TOOPERATE CONTINUOUSLYWITH A GROUND FAULT,MOUNT VERTICALLY WITHR & G TERMINALS DOWN.

BASE IS ELECTRICALLYCONNECTED TO TERMINAL G.

316.0

GR

188.0

(12.44)

(7.4

0)

FRONT VIEWSIDE VIEW

0.25-20 UNC STUD

V O L T A G E O N T H I S S U R F A C E R I S E ST O L I N E - T O - N E U T R A L V O L T A G E

W H E N A G R O U N D F A U L T O C C U R S

N

C A U T I O N

H I G H V O L T A G E



E R - 5 KV

SENS ING RES ISTOR

20 K

2500 VAC MAX

381.0

21.0

12.0

105.0

7.9

52.5

(15.00)

(0.83)

(0.47)

(4.1

3)

(0.3

1)

(2.0

7)

NEUTRAL CONNECTION

ALTERNATE NEUTRAL CONNECTION

TOP VIEW

0.25-20 UNCTHREADEDINSERT

10-32 THREADEDINSERT

RATINGS:MAXIMUM VOLTAGE . 2,500 VacMAXIMUM CURRENT . 125 mA

RESISTANCE . . . . . . . 20 kTHERMAL . . . . . . . . . . CONTINUOUS

5.

MINIMUM CLEARANCE FROM BASE254.0 (10.00)

NOTE 2

FIGURE 5. ER-5KV Sensing Resistor.



N



V O L T A G E A T T E R M I N A L N R I S E ST O L I N E - T O - N E U T R A L V O L T A G E


C A U T I O N


E R - 1 5 KV

SEN S IN G RES ISTOR

1 0 0 K

8 4 0 0 V A C MA X

1 M I N UTE MA X

422.0(16.61)

144.0

213.0

90.0

280.0

100.0

90.0

(5.6

7)

(8.3

9)

(3.5

3)

(11.0

0)

(3.9

4)

(3.5

3)

FRONT

MOUNTING DETAIL

SIDE

NOTES:

TOP

444.0

(17.50)

(14.37)(1.56) (1.56)

365.039.5 39.5


NOTE 3

1. DIMENSIONS IN MILLIMETRES(INCHES).

2. TERMINAL-BLOCK SCREWS:6-32 x 0.25.

3. MOUNTING SCREWS:M6 OR 0.25-20.

4. USE LIQUID-TIGHT GLAND FORTERMINAL-BLOCK-ENCLOSURECABLE ENTRY.

132.0

(5.2

0)

RATINGS:MAXIMUM VOLTAGE. . 8,400 VacMAXIMUM CURRENT . 84 mA

RESISTANCE . . . . . . . 100 kTHERMAL . . . . . . . . . . 1 MINUTE ON,

120 MINUTESOFF

R

G


0.25-20 BINDING HEAD

20.5

(0.8

1)

NOTE 2




800

60 340.0340.0

534

217

100.0

(31.5)

(2.4) (13.38)(13.38)

(21.0

)

(8.5

)(3

.94)

MOUNTING DETAIL

NOTES:

1. DIMENSIONS INMILLIMETRES (INCHES).

2. TERMINAL-BLOCK SCREWS:6-32 x 0.25.

3. MOUNTING SCREWS:M6 OR 0.25-20.

4. USE LIQUID-TIGHT GLANDFOR TERMINAL-BLOCK-ENCLOSURE CABLE ENTRY.

NOTE 3


320

(12.6

)

FRONT SIDE

N



V O L T A G E A T T E R M I N A L N R I S E ST O L I N E - T O - N E U T R A L V O L T A G E


C A U T I O N


E R - 2 5 KV

SENS ING RES ISTOR

1 0 0 K

1 4 , 4 0 0 V A C MA X

1 M I N UTE MA X

780(5

.67)

20.5

(30.7)

(0.8

1)

TOP

RATINGS:MAXIMUM VOLTAGE . 14,400 VacMAXIMUM CURRENT . 144 mA

RESISTANCE . . . . . . . 100 kTHERMAL . . . . . . . . . . 1 MINUTE ON,

120 MINUTES OFF

0.25-20 BINDING HEAD

144.0

R

G


NOTE 2




NOTES:

1. DIMENSIONS IN MILLIMETRES(INCHES).

2. INDICATES CLEARANCEREQUIRED.

3. PANEL THICKNESS 1.0 TO 6.0(0.04 TO 0.24).

4. NEMA 4X.

LEGEND PLATE

30.0(1.18)

LEGENDPLATE

22.2 (0.87) DIA

25.0

(0.9

8)

15.0

(0.5

9)

22.5

(0.8

9)

MOUNTING DETAIL

30.0 MINIMUM(1.18)

40

.0M

INIM

UM

(1.5

7)

LED PILOT LIGHTS

36.6(1.44)

17.3(0.68)

29.9(1.17)

43.5

(1.7

1)

PUSH BUTTON

36.6(1.44)

14.9(0.59)

29.9(1.17)

43.5

(1.7

1)

FIGURE 8. RK-302 Remote Indication and Reset

NOTES:

1. DIMENSIONS IN MILLIMETRES (INCHES).

2. NEMA 1.

FRONT VIEW

R E S I S T O R F A U L TR E S I S T O R F A U L T

G R O U N D F A U L TG R O U N D F A U L T

R E S E T


R K - 3 2 5

6 0 . 0

( 2 . 3 6 )

44.5

(1.75)(0.30)

(0.4

0)

7 .7

10

.0

96

.0

(3.7

8)

76

.0

(3.0

0)

(0 .875)

22.25

28

.58

(1.1

25

)

1 .25"CONDUIT

KNOCKOUT1.70" DIA

3.8 (0.15)DIA

MOUNTING DETAIL

OUTLINE

SIDE VIEW

CI/RI

+

GI

SW

3 0 . 0

( 1 . 1 8 )

25.0

(0.98)

FIGURE 9. RK-325 Remote Indication-and-Reset Assembly.



6 0 . 0

( 2 . 3 6 )

44.5

(1.75)(0.30)

(0.4

0)

7 .7

10

.0

96

.0

(3.7

8)

76

.0

(3.0

0)

(0 .875)

22.25

28

.58

(1.1

25

)

1 .25"CONDUIT

KNOCKOUT1.70" DIA

3.8 (0.15)DIA

MOUNTING DETAILSIDE VIEW FRONT VIEW

R E S I S T O R F A U L TR E S I S T O R F A U L T

G R O U N D F A U L TG R O U N D F A U L T


R K - 3 2 5 I

3 0 . 0

( 1 . 1 8 )

25.0

(0.98)

CI/RI

+

GI

OUTLINE

NOTES:


2. NEMA 1.

FIGURE 10. RK-325I Remote Indication Assembly.

60.2

31.0

47.5

21.0

(2.37)

(1.2

2)

(1.8

7)

(0.8

3)

RS1

RS2

CGI

GRI

+SW K1 K2

RS1

RS2

CGI

GRI

+SW K1 K2

SW CI/GI + GI/RI

TB1

INSTALLATION INSTRUCTIONS:

1. REMOVE FOUR LEFTMOST LOWER TERMINAL BLOCK SCREWS.2. PLACE RK-13 ON TERMINAL BLOCK AND REPLACE SCREWS.3. MAKE REQUIRED CONNECTIONS TO TERMINAL BLOCK TB1.

SIDE VIEWRK-13 SHOWN MOUNTED ON SE-105/SE-107/SE-325

NOTES:


FIGURE 11. RK-13 Relay Interface Module.



3.4 ISOLATED-GROUND CONNECTIONThe SE-325 is intended for use in installations where the

NGR is connected to local ground. Some installationsrequire the NGR to be isolated from local ground. SeeTechnical Information 3.1 “NGR Monitoring with IsolatedGround Beds” at www.startco.ca.

3.5 OVERHEAD LINESIn overhead-line applications, atmospheric conditions can

cause false resistor-fault trips. The “S” option or an SE-330is recommended for these applications.

3.6 REMOTE OPERATIONTerminals 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-panelLED’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. 8, 9, and 10.Standard LED indicator lamps are not compatible with theSE-325.

For general-purpose applications, use the RK-325 RemoteIndication-and-Reset Assembly or the RK-325I RemoteIndication Assembly. Connect terminals SW, GI, +, and RIto remote-kit terminals SW, GI, +, and CI/RI.

For 22-mm-component RK-302 applications, connectterminal X2 of the red ground-fault indicator to GI, terminalX2 of the red resistor-fault indicator to RI, and connectindicator X1 terminals to +. For remote reset, connect thenormally open push-button switch across terminals + andSW.

If indication is required from a separate voltage source, orif separate ground-fault and resistor-fault contacts arerequired, use an RK-13 Relay Interface Module. TheRK-13 mounts on the SE-325 lower terminal block and it iscompatible with the RK-302, RK-325 and RK-325I. SeeFigs. 1 and 11. Contact K1 closes when the GF LED is onand contact K2 closes when the RF LED is on.

3.7 GROUND-FAULT TESTINGUse CT-primary current injection to test the ground-fault

circuit. Fig. 12 shows test circuits using the Startco SE-400Ground-Fault-Relay Test Unit and the SE-100T Ground-Fault-Relay Tester. The SE-400 has a programmable outputof 0.5 to 9.9 A for a duration of 0.1 to 9.9 seconds. TheSE-100T has LO and HI outputs for 5- and 15-A resistance-grounded systems.

A test-record form is provided in Section 7 of thismanual. Record the test results and test dates on this form tomeet the requirements of the National Electrical Code(NEC). Retain the form so that the test data can be madeavailable to the authority having jurisdiction.

4. TECHNICAL SPECIFICATIONS

4.1 SE-325

Supply:ac ........................................... 120 or 240 Vac (+10, -50%),

50/60 Hz, 10 VAac/dc ...................................... 120 Vdc (+40, -8%), 5 W

or 120 Vac (+10, -29%),47 to 440 Hz, 5 VA

NOTE: Voltage between supply terminals (L1, L2) andground terminal (G) must not exceed 300 Vaccontinuous or 1,250 Vac under transientconditions.

Dimensions:Height.................................... 150 mm (5.9")Width.................................... 109 mm (4.3")Depth..................................... 100 mm (4.0")

Shipping Weight....................... 1 kg (2.2 lb)

Environment:Operating Temperature ........ -40 to 60°CStorage Temperature ............ -55 to 80°CHumidity............................... 85% Non-Condensing

Ground-Fault Circuit:CT Ratio................................ 200:5CT Input Burden................... 0.02 ΩTrip Level (1) ......................... 0.5, 2.0, or 4.0 AFrequency Response...........25 to 400 Hz,

25 to 110 Hz withOption H

Trip Time.............................. 0.1 to 2.0 s,0.1 to 5.0 s withOption T

Thermal Withstand (1)........... 200 A Continuous,2,500 A for 2 s

Trip-Level Accuracy ............ +10, -20%CT Lead Resistance Limit (2)

0.5 A Trip Level............2 Ω2 A Trip Level...............5 Ω4 A Trip Level...............5 Ω

Trip-Time Accuracy............. 10%Operating Mode.................... Latching,

Non-latching withOption N

(1) Currents referred to primary of CT200 for prospectiveground-fault currents less than 4,000 A.

(2) Typical maximum CT lead resistance to meet specifiedtrip level accuracy.



Resistor-Fault Circuit:Neutral-To-GroundTrip Voltage (VN) .................20 Vac to 2,000 Vac

AdjustableTrip Resistance, VN = 0

ER-600VC or ER-5KV.....2 kΩER-15KV or ER-25KV ....6 kΩ,

50 kΩ with Option STrip-Resistance Accuracy ....+5, -2% of Sensing

Resistor ResistanceTrip Time ..............................5 ± 0.5 s,

20 ± 3 s with Option SOperating Mode....................Latching,

Non-latching withOption N

Output Relay:CSA/ULContact Rating........1 mA to 4 A Resistive,

240 Vac or 28 VdcSupplemental Contact Ratings:

Make/carry 0.2 s..............10 ACarry continuous.............4 ABreak:

dc................................20 W resistive,10 W inductive(L/R = 0.04 s)

ac................................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 (F1) ...................4.0 A, 250 Vac,

Time DelayFuse Part Number .................Bussman MSL-4 or

Littelfuse 313.004

Operating Mode ...................UV (Fail-Safe) orSH (Non-Fail-Safe)

Remote Indication:+.............................................12 VdcGI/RI .....................................Current Sink,

560 Ω Internal

Optional RK-13 Module:Contact Ratings ..................100 mA, 120 VacContact Configuration ........N.O. (Form A)Reset Input .........................24 to 120 V (ac or dc),

Isolated

PWB Conformal Coating......... MIL-1-46058 qualified,UL QMJU2 recognized

4.2 SENSING RESISTORS

ER-600VC:Maximum Voltage .......... 600 VacMaximum Current........... 30 mAResistance ....................... 20 kΩThermal: 420 Vac ...........................Continuous 600 Vac ...........................6 minutes on,............................................60 minutes offShipping Weight ................300 g (0.7 lb)

ER-5KV:Maximum Voltage .......... 2,500 VacMaximum Current........... 125 mAResistance ....................... 20 kΩThermal ..............................ContinuousShipping Weight ................5.0 kg (11 lbs)

ER-15KV:Maximum Voltage .......... 8,400 VacMaximum Current........... 84 mAResistance ....................... 100 kΩThermal ..............................1 minute on,............................................120 minutes offShipping Weight ................5.0 kg (11 lbs)

ER-25KV:Maximum Voltage .......... 14,400 VacMaximum Current........... 144 mAResistance ....................... 100 kΩThermal ..............................1 minute on,............................................120 minutes offShipping Weight ................20 kg (44 lbs)

4.3 CURRENT TRANSORMER

CT200:Current Ratio................... 200:5 AInsulation ........................ 600-V ClassWindow Diameter........... 56 mm (2.2”)Shipping Weight ............. 1 kg (2.2 lbs)

Certification ........................ CSA, Canada and USALR 53428

USC

R

Australia

Commonwealth of PennsylvaniaSE-325........ BOTE 1767-99SE-325P...... BOTE 1797-00



5. ORDERING INFORMATION

SE-325

120-Vac SupplyE 240-Vac SupplyD 120-Vac/dc Supply

(2) S Extended Resistor Trip TimeH Harmonic FilteringN Non-latching OperationT Extended G-F Trip Time

Option List(1)

(1)

2

List options required in order shown above.Standard, leave blank.

SE-325P ....Approved byThe Commonwealth of Pennsylvania

for 4,800- NGR.

Requires 20-k sensing resistor.

( )

Continuously Rated Sensing Resistors:ER-600VC (20 kΩ) ..............For system voltages up to

1,000 VacER-5KV (20 kΩ) ..................For system voltages up to

5 kVacOne-Minute-Rated Sensing Resistors:

ER-15KV (100 kΩ) ..............For system voltages up to15 kVac

ER-25KV (100 kΩ) ..............For system voltages up to25 kVac

Ground-Fault CT:CT200....................................56 mm (2.2") Window

Remote Indication and Reset:RK-302..................................Includes two LED pilot

lights, a reset push button,and legend plates

RK-325..................................Indication-and-ResetAssembly

RK-325I ................................Indication AssemblyRK-13....................................Relay Interface Module

6. WARRANTY

The SE-325 Neutral-Grounding-Resistor Monitor iswarranted to be free from defects in material andworkmanship for a period of five years from the date ofpurchase.

Startco Engineering Ltd. will (at Startco’s option)repair, replace, or refund the original purchase price of anSE-325 that is determined by Startco to be defective if itis returned to the Startco factory, freight prepaid, withinthe warranty period. This warranty does not apply torepairs required as a result of misuse, negligence, anaccident, improper installation, tampering, or insufficientcare. Startco Engineering Ltd. does not warrant productsrepaired or modified by non-Startco Engineering Ltd.personnel.

Startco Engineering Ltd. is not liable for contingent orconsequential damages; for expenses sustained as a resultof incorrect application, incorrect adjustment, or amalfunction; or for expenses resulting from the use of, orinability to use, the product.



7. TEST PROCEDURES

7.1 GROUND-FAULT PERFORMANCE TESTTo meet the requirements of the National Electrical

Code (NEC), as applicable, the overall ground-faultprotection system requires a performance test when firstinstalled. A written record of the performance test is tobe retained by those in charge of the electrical installationin order to make it available to the authority havingjurisdiction. A test-record form is provided for recordingthe date and the final results of the performance tests.The following ground-fault system tests are to beconducted by qualified personnel:

a) Evaluate the interconnected system in accordance withthe overall equipment manufacturer’s detailedinstructions.

b) Verify proper location of the ground-fault currenttransformer. Ensure the cables pass through theground-fault-current-transformer window. This checkcan be done visually with knowledge of the circuit.The connection of the current-transformer secondaryto the SE-325 is not polarity sensitive.

c) Verify that the system is correctly grounded and thatalternate ground paths do not exist that bypass thecurrent transformer. High-voltage testers andresistance bridges can be used to determine theexistence of alternate ground paths.

d) Verify proper reaction of the circuit-interruptingdevice in response to a simulated or controlledground-fault current. To simulate ground-faultcurrent, use CT-primary current injection. Fig. 12ashows a test circuit using a Startco SE-400 Ground-Fault-Relay Test Unit. The SE-400 has aprogrammable output of 0.5 to 9.9 A for a duration of0.1 to 9.9 seconds. Set the test current to 0.6, 2.3, or4.6 A for SE-325 units set at 0.5, 2.0, or 4.0 Arespectively. Fig. 12b shows a test circuit using aStartco SE-100T Ground-Fault-Relay Tester. TheSE-100T provides a test current of 0.65 or 2.75 A fortesting 0.5- and 2.0-A trip levels. Inject the testcurrent through the current-transformer window for atleast 2.5 seconds. Verify that the circuit under test hasreacted properly. Correct any problems and re-testuntil the proper reaction is verified.

e) Record the date and the results of the test on theattached test-record form.

SE-400

SE-325

RMT1REMOTE

TEST 9

8

1

5

3

11 12

RMT2

L

L

N

N

L1

L1

CT1

CT2

OP1 OP2

L2

L2

a) USING SE-400

0.65 A

2.75 A

NEUTRAL

GROUNDING

RESISTOR

CT200

GROUND-FAULT CT

ER

N

R

G

R

b) USING SE-100T

SE-100T

SE-325

REMOTETEST

RMT

L

L

N

N

L1

L1

CT1

CT2

C

L2

L2NEUTRAL

GROUNDING

RESISTOR

CT200

GROUND-FAULT CT

ER

N

R

G

R

LO

HI

FIGURE 12. Ground-Fault-Test Circuits

TABLE 2. GROUND-FAULT-TEST RECORD

DATE TEST RESULTS

Retain this record for the authority having jurisdiction.



7.2 RESISTOR-FAULT TESTSPerform tests with system de-energized and supplyvoltage applied to the SE-325.

7.2.1 OPEN TESTTest Equipment: 20-kΩ and 100-kΩ, ¼-watt, 1% resistors.

Procedure:• Remove connections to SE-325 R and G terminals.• Connect the 20-kΩ resistor to R and G terminals.• Set the RES switch to 20K.• 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.• Connect the 100-kΩ 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:• Reconnect SE-325 R and G connections.• Set the RES switch to match sensing resistor.• Press RESET.• PASS: The RESISTOR FAULT LED should be off.

7.2.2 VOLTAGE TESTTest Equipment: 0 to 120 Vac voltage source and multimeter.

NOTE: Applying the test voltage to the R and G terminals willdamage the SE-325 and the ER sensing resistor. The RESTRIP LEVEL is the trip voltage at terminal N, not terminal R.

Procedure:• Check the ER sensing resistor connection to the SE-325.• Disconnect the wire from sensing resistor terminal N.• 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-kΩ sensors or

120 Vac for 100-kΩ sensors and wait 5 seconds(20 seconds with Option S).

• PASS: The SE-325 should trip on RESISTOR FAULT.

7.3 SENSING-RESISTOR TESTTest Equipment: Multimeter.

Procedure:• Disconnect the sensing resistor.• Measure the resistance between sensing-resistor terminals

R and N.• PASS: Resistance should be between 19.6 and 20.4 kΩ

for 20-kΩ sensing resistors. Resistance should be between98 and 102 kΩ for 100-kΩ sensing resistors.

• Measure the resistance between sensing-resistor terminalsR and G in both directions.

• PASS: Resistance should be greater than 10 MΩ in bothdirections.

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