Leaded ResistoRs
Carbon Film Resistors
Non-Inductive &
Flame-Proof Type
Normal & Miniature Style [ NCR Series ]
FeatURes
Power Rating
Resistance Tolerance
T.C.R.
Flameproof Multi-layer Coating Meets
Flameproof Feature Meets Overload Test
1/4W, 1/2W, 1W, 2W, 3W
±5%, ±10%
see Table 1
UL-94V-0
UL-1412
iNtRodUCtioN
The NCR Series Carbon Film Non-Inductive &
Flame-Proof Resistors are manufactured by
coating a homogeneous film of pure carbon
on high grade ceramic rods. Tinned connecting
leads of electrolytic copper are welded to the
end-caps. The inductance is
<1μH.
The resistors are coated with layers of gray col-
or lacquer for normal size & pink color lacquer
for miniature size.
deRatiNG CURVe
For resistors operated in ambient temperatures above 70°C, power rating must be derated
in accordance with the curve below.
Rated Load (%)
70
100
80
60
40
20
20
40
60
80
100 120 140 160
155 °C
Ambient Temperature (°C)
taBLe 1 teMPeRatURe CoeFFiCieNt
VaLUe RaNGe
Under 5K
Ω
5K - 10K
Ω
Max. VaLUe oF teMP. CoeFFiCieNt PPM/°C
-500
-800
diMeNsioNs
stYLe
Normal
ød
H
L
th color code: green
øD
NCR-25
NCR-50
NCR100
NCR200
Miniature
NCR50S
NCR1WS
NCR2WS
NCR3WS
diMeNsioN
L
6.3±0.5
9.0±0.5
11.5±1.0
15.5±1.0
ød
2.4±0.2
3.3±0.3
4.5±0.5
5.0±0.5
H
28±2.0
26±2.0
35±2.0
33±2.0
Unit: mm
ød
0.55±0.05
0.55±0.05
0.8±0.05
0.8±0.05
3
Note:
eLeCtRiCaL CHaRaCteRistiCs
stYLe
Power Rating at 70°C
Maximum Working Voltage
Maximum Overload Voltage
Voltage Proof
Resistance Range
Operating Temp. Range
Temperature Coefficient
NCR-25
1/4W
250V
500V
500V
NCR50s
1/2W
300V
600V
350V
700V
700V
NCR-50
NCR1Ws
1W
400V
800V
500V
1,000V
1,000V
NCR100
NCR2Ws
2W
NCR200
NCR3Ws
3W
2.2
Ω
- 10K
Ω
for E24 series value
-55°C to +155°C
see Table 1
Note: Special value is available on request
eNViRoNMeNtaL CHaRaCteRistiCs
PeRFoRMaNCe test
Short Time Overload
Voltage Proof
Temperature Coefficient
Insulation Resistance
Solderability
Solvent Resistance of Marking
Robustness of Terminations
Periodic-pulse Overload
Damp Heat Steady State
Endurance at 70°C
Temperature Cycling
Resistance to Soldering Heat
Accidental Overload Test
test MetHod
IEC 60115-1 4.13
IEC 60115-1 4.7
IEC 60115-1 4.8
IEC 60115-1 4.6
IEC 60115-1 4.17
IEC 60115-1 4.30
IEC 60115-1 4.16
IEC 60115-1 4.39
IEC 60115-1 4.24
IEC 60115-1 4.25
IEC 60115-1 4.19
IEC 60115-1 4.18
IEC 60115-1 4.26
2.5 times RCWV for 5 Sec.
in V-block for 60 Sec., test voltage by type
-55°C to +155°C
in V-block for 60 Sec.
235±5°C for 3±0.5 Sec.
IPA for 5±0.5 Min. with ultrasonic
Direct load for 10 Sec. in the direction of the terminal leads
4 times RCWV 10,000 cycles (1 Sec. on, 25 Sec. off)
40±2°C, 90-95% RH for 56 days, loaded with 0.1 times RCWV
70±2°C at RCWV for 1,000 Hr. (1.5 Hr. on, 0.5 Hr. off)
-55°C
Room Temp.
+155°C
Room Temp. (5 cycles)
260±3°C for 10±1 Sec., immersed to a point 3±0.5mm from the
body
4 times RCWV for 1 Min.
aPPRaise
±0.75%+0.05
Ω
for normal style
±2.0%+0.05
Ω
for miniature style
By type
By type
>1,000M
Ω
95% Min. coverage
No deterioration of coatings and
markings
≥2.5kg (24.5N)
±1.0%+0.05
Ω
±3.0%+0.05
Ω
±3.0%+0.05
Ω
±1.0%+0.05
Ω
±1.0%+0.05
Ω
No evidence of flaming or arcing
Note: Rated Continuous Working Voltage (RCWV) =
Power Rating x Resistance Value