99

Revised: July 12, 2010

© 2010 Littelfuse, Inc

250R Series

Radial Leaded > 250R Series

Specifications are subject to change without notice.

Please refer to www.littelfuse.com/series/250R.html for current information.

The 250R Series is designed to protect against short

duration high voltage fault currents (power cross or power

induction surge) typically found in telecom applications

(250Vrms). The series can be used to help telecom

networking equipment meet the protection requirements

specified in ITU K.20 and K.21.

Electrical Characteristics

Part Number

I

hold

(A)

I

trip

(A)

V

max

V

I

max

(A)

P

d

typ.

(W)

Maximum Time

To Trip

Resistance

Agency

Approvals

Current

(A)

Time

(Sec.)

R

min

(Ω)

R

typ

(Ω)

R

1max

(Ω)

250R080

0.08

0.16

250/60

3

1

0.35

3

14

22

33

XX

250R080T

0.08

0.16

250/60

3

1

0.35

3

15

22

33

XX

250R120

0.12

0.24

250/60

3

1

1

1.5

4

8

16

XX

250R120-RA

0.12

0.24

250/60

3

1

1

1.0

7

9

16

XX

250R120-RC

0.12

0.24

250/60

3

1

1

0.85

5.4

7.5

14

XX

250R120-RF

0.12

0.24

250/60

3

1

1

0.7

6

10.5

16

XX

250R120-R1

0.12

0.24

250/60

3

1

1

0.8

6

9

16

XX

250R120-R2

0.12

0.24

250/60

3

1

1

0.7

8

10.5

16

XX

250R120-R3

0.12

0.24

250/60

3

1

1

1

8

10

16

XX

250R120T

0.12

0.24

250/60

3

1

1

1.2

7

12

16

XX

250R145

0.145

0.29

250/60

3

1

1

2.5

3

6

14

XX

250R145-RA

0.145

0.29

250/60

3

1

1

5

3

5.5

12

XX

250R145-RB

0.145

0.29

250/60

3

1

1

2.5

4.5

6

14

XX

250R145T

0.145

0.29

250/60

3

1

1

2.0

5.4

7.5

14

XX

250R180

0.18

0.65

250/60

10

1.8

1

21

0.8

2.2

4

XX

250R180T

0.18

0.65

250/60

10

1.8

1

20

1.4

3.9

4.5

XX

Items with T at end of part number = pre-tripped device. See Part Ordering Number System section of this data sheet for additional information.

Description

Features

Applications

range, 60VDC operating

voltage

resistance ranges available

Free and Halogen-Free*

Equipment (CPE)

telecom centers

250R Series

Agency Approvals

AGENCY

AGENCY FILE NUMBER

E183209

R50120008

I

I

V

V

I

P

R

R

R

Caution: Operation beyond the specified rating may result in damage and possible arcing

and flame.

* Effective January 1, 2010, all 250R PTC products will be manufactured Halogen Free (HF). Existing Non-Halogen Free 250R PTC products may continue to be sold, until supplies are depleted.