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Equipment (CPE)
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telecom centers
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POLY-FUSE® Resettable PTCs
Radial Leaded > 250R Series
250R Series
Description
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
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range, 60VDC operating
voltage
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resistance ranges available
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Agency Approvals
AGENCY
AGENCY FILE NUMBER
E183209
Applications
R50120008
Electrical Characteristics
MaximumTime
ToTrip
Agency
Resistance
P d
typ.
(W)
Vmax
/ V
Approvals
I hold
(A)
I trip
(A)
I max
(A)
Part Number
R min
(Ω)
R typ
(Ω)
R 1max
(Ω)
V
Current Time
int
op
(A)
0.35
0.35
1
(Sec.)
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
250R080
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
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
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
3
3
1
1
3
14
15
4
22
22
8
33
33
16
16
14
16
16
16
16
16
14
12
14
14
4
250R080T
250R120
3
3
1
1.5
1.0
0.85
0.7
0.8
0.7
1
250R120-RA
250R120-RC
250R120-RF
250R120-R1
250R120-R2
250R120-R3
250R120T
3
1
1
7
9
3
1
1
5.4
6
7.5
10.5
9
3
1
1
3
1
1
6
3
1
1
8
10.5
10
12
6
3
1
1
8
3
1
1
1.2
2.5
5
7
250R145
3
1
1
3
250R145-RA
250R145-RB
250R145T
3
1
1
3
5.5
6
3
1
1
2.5
2.0
21
4.5
5.4
0.8
1.4
3
1
1
7.5
2.2
3.9
250R180
10
10
1.8
1.8
1
250R180T
1
20
4.5
Items withT at end of part number = pre-tripped device. See Part Ordering Number System section of this data sheet for additional information.
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Vop= The device regular operation voltage
R min = Minimum resistance of device in initial (un-soldered) state.
R typ =Typical resistance of device in initial (un-soldered) state.
Caution: Operation beyond the specified rating may result in damage and possible arcing
and flame.
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97
© 2011 Littelfuse, Inc
250R Series
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/250R.html for current information.
Revised: August 31, 2011