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Protection Relays & Controls

NGR SERIES – US

Specifications: 4160 V NGR Systems

Voltage

4160 V line-to-line, 2400 V line-to-neutral

Let-Through Current

5 A, 10 A, 15 A, or 25 A

Resistance

480 Ω (5 A), 240 Ω (10 A), 160 Ω (15 A),

or 96 Ω (25 A)

Tolerance

+/- 10 % resistance

Duty Cycle

Continuous-duty or 10-second-duty rating

Frequency

50-60 Hz

Current Transformer

ELCT5-31:

For use with SE-330 NGR Monitor

Turns Ratio: 100:1

Current Rating: 5:0.05 A

Primary Rating with SE-330: 5 A when

connected to terminals 8 and 11

GF Trip Range: 100 mA to 5 A

Window Diameter: 31 mm (1.22”)

SE-CS10-2.5:

For use with SE-330 NGR Monitor

Turns Ratio: 200:1

Current Rating: 12.5:0.0625 A

Primary Rating with SE-330: 10 A when

connected to terminals 8 and 11

GF Trip Range: 200 mA to 10 A

Window Diameter: 63.5 mm (2.5”)

Turns Ratio: 100:5

Current Rating: 100:5 A

Primary Rating with SE-330: 20 A when

connected to terminals 9 and 11

GF Trip Range: 400 mA to 20 A

Window Diameter: 40 mm (1.56”)

CT200:

For use with SE-325 NGR Monitor

Turns Ratio: 200:5

Current Rating: 200:5 A

GF Trip Range: 0.5, 2.0, 4.0 A

Window Diameter: 56 mm (2.2")

Sensing Resistor

ER-5KV

Optional ER-5WP for outdoor applications

Insulation Level

75 KV BIL

Temperature Rise

Continuous-duty rated: 385 °C (725 °F)

10-second-duty rated: 760 °C (1400 °F)

Resistor Type

Stainless Steel Wire Wound

Dimensions

Refer to dimensions drawings

Weights

5 A, continuous-duty rated:

192 kg (424 lbs)

10 A, continuous-duty rated: 235 kg (519 lbs)

15 A, continuous-duty rated: 258 kg (568 lbs)

25 A, continuous-duty rated: 320 kg (705 lbs)

Disclaimer Notice – Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their

own applications. Littelfuse products are not designed for, and may not be used in, all applications. Read complete Disclaimer Notice at www.littelfuse.com/product-disclaimer.

5 A, 10-second-duty rated:

136 kg (300 lbs)

10 A, 10-second-duty rated: 136 kg (300 lbs)

15 A, 10-second-duty rated: 136 kg (300 lbs)

25 A, 10-second-duty rated: 136 kg (300 lbs)

Altitude

0-1000 masl

Enclosure Style

NEMA 3R, galvanized steel

Finish

Powder coated

Color

ANSI 61 grey

Mounting

Floor mount

Siesmic Bracing

Included

Approvals

cULus or CSA at customer request

Warranty

12 months in service or 18 months from

the date of shipment, whichever

occurs first

Accessories

SE-325 Neutral Grounding Resistor Monitor

Basic ground-fault and neutral-grounding resistor

monitoring relay that measures neutral current,

neutral-to-ground voltage, and neutral-to-ground

continuity.

SE-330 Neutral Grounding Resistor Monitor

Advanced ground-fault and neutral-grounding

resistor monitoring relay that measures neutral

current, neutral-to-ground voltage, and neutral-to-

ground resistance.

NGRM-ENC Enclosed Neutral Grounding

Resistor (NGR) Monitor

Type 4X enclosure housing a Littelfuse Startco

SE-325 or SE-330 Neutral Grounding Resistor

Monitor and optional accessories that include

a 480/600 V control power transformer (CPT),

faulted-phase indication (FPI; implemented

with an EL3100 Ground-Fault & Phase-Voltage

Indicator), earth-leakage panel meter, pulse-enable

control, and mounting options. Appropriate fusing

is included and field wiring is to terminal blocks.

Custom NGR Systems

Additional custom NGR systems are also available from

Littelfuse. For NGR systems not listed on this sheet please

contact Littelfuse by emailing NGRquotes@Littelfuse.com