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.
Features
• 0.08 – 0.18 hold current
range, 60VDC operating
voltage
• 250VAC interrupt rating
• Fast time–to-trip
AGENCY FILE NUMBER
E183209
R50120008
Agency Approvals
AGENCY
• Binned and sorted narrow
resistance ranges available
• RoHS compliant, Lead-
Free and Halogen-Free*
Applications
• Customer Premises
Equipment (CPE)
• Central Office (CO)/
telecom centers
• LAN/WAN equipment
• Access equipment
Electrical Characteristics
I
hold
(A)
0.08
0.08
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.145
0.145
0.145
0.145
0.18
0.18
I
trip
(A)
0.16
0.16
0.24
0.24
0.24
0.24
0.24
0.24
0.24
0.24
0.29
0.29
0.29
0.29
0.65
0.65
V
max
V
int
/ V
op
250/60
250/60
250/60
250/60
250/60
250/60
250/60
250/60
250/60
250/60
250/60
250/60
250/60
250/60
250/60
250/60
I
max
(A)
3
3
3
3
3
3
3
3
3
3
3
3
3
3
10
10
P
d
typ.
(W)
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1.8
1.8
Maximum Time
To Trip
Current
(A)
0.35
0.35
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Time
(Sec.)
4.0
4.0
2.5
2.5
3.0
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
20
21
R
min
(Ω)
14
15
4
7
5.4
6
6
8
8
7
3
3
4.5
5.4
0.8
1.4
Resistance
R
typ
(Ω)
22
22
8
9
7
.5
10.5
9
10.5
10
12
6
5.5
6
7
.5
2.2
3.9
R
1max
(Ω)
33
33
16
16
14
16
16
16
16
16
14
12
14
14
4
4.5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Part Number
Agency
Approvals
250R080
250R080T
250R120
250R120-RA
250R120-RC
250R120-RF
250R120-R1
250R120-R2
250R120-R3
250R120T
250R145
250R145-RA
250R145-RB
250R145T
250R180
250R180T
Items with T at end of part number = pre-tripped device. See Part Ordering Number System section of this data sheet for additional information.
I
hold
= Hold current: maximum current device will pass without tripping in 20°C still air.
I
trip
= Trip current: minimum current at which the device will trip in 20°C still air.
V
int
= Maximum voltage the device can withstand without damage at rated current (I max)
V
op
= The device regular operation voltage
I
max
= Maximum fault current device can withstand without damage at rated voltage (V
max
)
P
d
= Power dissipated from device when in the tripped state at 20°C still air.
* 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.
Specifications are subject to change without notice.
Revised: 03/22/17
POLY-FUSE Resettable PTCs
®
E
F
E
Radial Leaded > 250R Series
Dimensions
A
Figure 1
C
A
Figure 2
C
Part Marking System
Littelfuse
Trademark
080
XXXX
250
B
B
Littelfuse
Voltage Rating
Trademark
Current Rating
Date Code
(Contact Littelfuse
for additional
information)
120
XXXX
250
Voltage Rating
Current Rating
Date Code
(Contact Littelfuse
for additional
information)
D
D
E
F
E
F
Figure 1
A
Part Number
250R080
Littelfuse
Trademark
Figure 2
B
mm
Max.
5.8
5.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
9.5
9.5
Inches
Max.
0.39
Voltage Rating
Current Rating
Date Code
(Contact Littelfuse
for additional
information)
C
mm
Max.
9.9
9.9
11
11
11
11
11
11
11
11
11
11
11
11
12
12
Inches
Max.
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.18
mm
Max.
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
Min.
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0.19
D
Inches
mm
Min.
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
Typ.
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
E
Inches
mm
Typ.
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
Physical Characteristics
Lead (dia)
Inches
0.026
0.026
0.026
0.026
0.026
0.026
0.026
0.026
0.026
0.026
0.026
0.026
0.026
0.026
0.026
0.026
mm
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
Material
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Sn/Cu
Figure
1
Littelfuse
Voltage Rating
Trademark
Current Rating
Date Code
(Contact Littelfuse
for additional
information)
Inches
Max.
0.23
0.23
250
120
0.27
0.27
0.27
0.27
0.27
0.27
0.27
0.27
0.27
0.27
0.27
0.27
0.37
0.37
XXXX
250R080T
250
080
250R120
XXXX
1
0.39
2
0.43
250R120-RA
250R120-RC
250R120-RF
250R120-R1
250R120-R2
250R120-R3
250R120T
250R145
250R145-RA
250R145-RB
250R145T
250R180
250R180T
2
2
2
2
2
2
2
2
2
2
2
1
1
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.47
0.47
WARNING
• Users shall independently assess the suitability of these devices for each of their applications
• Operation of these devices beyond the stated maximum ratings could result in damage to the devices and lead to electrical arcing and/or fire
• These devices are intended to protect against the effects of temporary over-current or over-temperature conditions and are not intended to perform as protective devices where such
conditions are expected to be repetitive or prolonged in duration
• Exposure to silicon-based oils, solvents, electrolytes, acids, and similar materials can adversely affect the performance of these PPTC devices
• These devices undergo thermal expansion under fault conditions, and thus shall be provided with adequate space and be protected against mechanical stresses
• Circuits with inductance may generate a voltage (L di/dt) above the rated voltage of the PPTC device.
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