Littelfuse SE-330HV User Manual

Protection Relays & Controls

NGR

L2

CT

L1

SE-330 SERIES

ER SERIES

(Sensing Resistor)

(NGR Monitor)

Neutral-Grounding-Resistor Monitoring

SE-330, SE-330HV SERIES (PGR-5330)

Neutral-Grounding-Resistor Monitor

Simplified Circuit Diagram

Description

The SE-330 is an advanced ground-fault and neutral-grounding­resistor monitoring relay. It measures neutral current, neutral-to­ground voltage, and neutral-to-ground resistance. It provides
continuous monitoring of the neutral-to-ground path to verify
that the neutral-grounding resistor (NGR) is intact. This is of
utmost importance—an open NGR renders current-sensing
ground-fault protection inoperative and could result in a false
belief that the system is functioning properly. The SE-330 can be
used with low- and medium-voltage transformers and
generators with low- or high-resistance grounding used in
processing, manufacturing, chemical, pulp and paper, petroleum,
and water-treatment facilities. For high-voltage applications, use
the SE-330HV. For applications that require conformance to
Australian standard AS/NZS 2081.3:2002, see the SE-330AU.

Resistor Monitoring

The SE-330 combines the measured values of resistance,
current, and voltage to continuously determine that the NGR
is intact. It is able to detect a resistor failure with or without
a ground fault present. Sensing resistors are matched to the
system voltage and are used to monitor NGRs on systems up
to 72 kV.

Ground-Fault Monitoring

The SE-330 uses an application-appropriate current transformer
to reliably detect ground-fault currents as small as 100 mA. DFT

B

filtering ensures that false trips due to harmonic noise from
adjustable-speed drives do not occur. Should the resistor open
and a ground fault subsequently occur, the SE-330 will detect
the fault through voltage measurement, while other current-only

A

sensing relays would be ineffective.

Pulsing Ground-Fault Location

For detailed wiring diagram, see adjacent page.

Ordering Information

ORDERING
NUMBER

POWER
SUPPLY

COMM CERTIFICATION

SE-330 - X X - X

0=RS-232

SE-330
for all apps.
35 kV or less

SE-330HV
for 72 kV
apps.

NOTE: For Australian applications, see the SE-330AU on pg. 38.

ACCESSORIES REQUIREMENT

0=120/240
Vac/Vdc

2=48 Vdc

1=RS-232 &
DeviceNet

2=RS-232 &
Profibus

3=RS-232 &

& Modbus

®

EtherNet/IP™

TCP

0=CSA,

™

UL, C-Tick

1=CSA,
UL, CE,
C-Tick

®

ER Series Sensing Resistor Required
Current Transformer Required
SE-IP65CVR-G Optional
SE-MRE-600 Optional
RK-332 Optional
NGRM-ENC Optional

Littelfu se res erves the right to m ake product c hanges, without notice. Material in this docum ent is as accurate as known a t the time of publication. Visit Lit telfuse.c om for the mos t up-to-date inf ormation.

© 2013 Littelfuse Protection Relays & Controls

© 2013 Littelfuse Protection Relays & Controls
Littelfuse.com/se-330

K4 UNIT HEALTHY
CONTACT

X

0=Normally Open

1=Normally Closed

The SE-330 is capable of controlling a pulsing contactor, which is
used to switch the NGR resistance in a pulsing-compatible NGR
package. The resulting ground-fault current is distinguishable
from charging currents and noise and will only appear upstream
of the ground fault, making fault location fast and easy, even
without isolating feeders or interrupting loads.

Accessories

A

B

ER Series Sensing Resistor

Required interface between the power system
and the SE-330/SE-330HV. Eliminates hazardous
voltage levels at the relay.

EFCT Series Ground-Fault Current Transformer

Sensitive ground-fault current detection (5 A primary).

SE-CS30 Series Ground-Fault Current Transformer

Sensitive ground-fault current detection (30 A primary).

Other Current Transformer

For low-resistance NGRs choose a CT primary
approximately equal to the NGR rating.

Rev: 4-B-050213

Based on Manual Rev 9

Protection Relays & Controls

Neutral-Grounding-Resistor Monitoring

SE-330, SE-330HV SERIES (PGR-5330)

Neutral-Grounding-Resistor Monitor

Features & Benefits

FEATURES IEEE # BENEFITS

Continuous NGR monitoring

Ground-fault detection

Adjustable pickup (2-100%)

Adjustable time delay (0.1 - 10 s)

Universal CT compatibility

Output contacts

Analog output (4 - 20 mA)

Pulsing output

Data logging

Harmonic filtering (DFT)

Local communications

Network communications

Software
Selectable contact

operating mode
Selectable reset mode
Calibrate push button
Unit-healthy output
Conformal coating

3

50G/N, 51G/N,

59N

Detects resistor failure within seconds, reduces transient-overvoltage risk, removes risk of ground-fault-detection failure

Main or backup protection to detect a ground fault anywhere on the monitored system

Select greatest sensitivit y without false operation

Adjustable trip delay allows quick protection and system coordination

Allows the use of a CT that gives required ground-fault settings

Two Form C (Ground Fault and Resistor Fault), Two Form A (Trip/Pulse, Healthy)

Allows for connecting an optional PGA-0500 meter or control system

Control the operation of a pulsing ground-fault-location circuit

On-board 10-event recorder helps with system diagnostics

Eliminate false trips due to harmonic noise from ASDs

RS-232 port to view measured values, log to a PC and check event records

Remotely view measured values and event records, reset trips, and cause a remote trip

PC-interface software (SE-MON330) is included
Selectable fail-safe or non-fail-safe operating modes allows connection to shunt or undervoltage breaker coil

or alarm circuit
Selectable latching or auto-reset operation
Ensures resistor-failure sensitivity is correct
Verifies SE-330 is operating correctly
Internal circuits are conformally coated to protect against corrosion and moisture

Typical Values

SYSTEM

VOLTAGE

(VOLTS)

480 5 55 ER-600VC 20 k

600 5 69 ER-600VC 20 k
2,400 5 277 ER-5KV 20 k
4,160 5 480 ER-5KV 20 k
7,200 10 416 ER-15KV 100 k

14,400 15 554 ER-15KV 100 k

DISCLAIMER: The above table is for illustrative purposes only. Actual values may differ based on a variety of individual system considerations, such as capacitive charging current and coordination study results.

Wiring Diagram

POWER SYSTEM
NEUTRAL (X0)

SENSING RESISTOR

ER SERIES

N

CURRENT TRANSFORMER

EFCT FAMILY

NEUTRAL-GROUNDING RESISTOR SENSING RESISTOR

(required)

(required)

CONTROL
POWER

G

CURRENT

(AMPERES)

1

2

3

R

6

7

A

8

9

10

B

11

NEUTRAL-GROUNDING­RESISTOR MONITOR

SE-330 SERIES

R

G

EFCT

1 A

5 A

COMMON

RESISTANCE

(OHMS)

UNIT

HEALTHY

ANALOG
OUTPUT

4-20 mA

TRIP OR

PULSING

GROUND

FAU LT

RESISTOR

FAU LT

+24 Vdc

0 V

+

12

13

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

MODEL

RESET

PULSE
ENABLE

RESISTANCE

(SWITCH S5 SETTING)

Ω
Ω
Ω
Ω

Ω
Ω

Specifications

IEEE Device Numbers Ground Fault (50G/N, 51G/N, 59N),
Checking Relay (3), Lockout Relay (86)

Input Voltage See ordering information
Dimensions H 213 mm (8.4"); W 98 mm (3.9"); D 132 mm (5.2")
GF Trip-Level Settings 2-100% of CT-Primary Rating
GF Trip-Time Settings 0.1-10 s
Vn Trip-Level Settings 20-2,000 Vac (≤5 kV systems)

100-10,000 Vac (>5 kV systems)

Contact Operating Mode Selectable fail-safe or non-fail-safe (K1)
Harmonic Filtering Standard feature
Reset Button Standard feature
Output Contacts Two Form A and two Form C
Pulsing Circuit 1.0-3.0 s in 0.2 s increments
Approvals

CE (European Union) optional, C-Tick (Australian)
Communications RS-232; (standard) DeviceNet
Ethernet (optional)

Analog Output 4-20 mA, self or loop powered
Conformally Coated Standard feature
Warranty 5 years
Mounting Panel and Surface

Littelfu se res erves the right to m ake product c hanges, without notice. Material in this docum ent is as accurate as known a t the time of publication. Visit Lit telfuse.c om for the mos t up-to-date inf ormation.

© 2013 Littelfuse Protection Relays & Controls

© 2013 Littelfuse Protection Relays & Controls
Littelfuse.com/se-330

GROUND-FAULT

PICKUP LEVEL

(AMPERES)

2.5 170

2.5 200

2.5 800
3 1,700
2 170 x 5 = 850
3 340 x 5 = 1,700

CSA certified

, UL Listed (E340889),

V

PICKUP LEVEL

N

(VOLTS)

™

, Profibus®,

Rev: 4-B-050213

Based on Manual Rev 9