METAL OXIDE FILM RESISTORS, FLAMEPROOF
1. Applicable Scope:
This standard specification is for use in consumer electronics, computers, telecommunications, control
instruments...etc.
2. Part Number:
It is composed by Type, Rated Wattage, Nominal Resistance, Tolerance and Package/Terminal Form
. e.g.
RSS
Type
2W
Rated Wattage
10R
Nominal Resistance
J
Tolerance
T/B
Package/Terminal Form
2.1 Type :
Metal Oxide Film Resistors, Flameproof are called "RSN" &"RSS"(small size).
2.2 Rated Wattage:
Shown by "W", such as 1/4W, 1/2W, 1W, 2W, 3W, 3WL, 4W, 5W, 6W, 7W, 10W.
2.3 Nominal Resistance:
Ω , KΩ are its unit, which be in accordance with JIS-C6409 article 6 (EIA RS-196A) series.
Letter "10R" indicates resistance value 10Ω.
2.4 Tolerance:
It is measured by Bridge-method at room temperature and expressed by a capital letter.
G=±2% , J=±5% .
2.5 Package/Terminal Form:
T/R=tape & reel ; T/B=tape in box; Nil=Bulk; MG form, F forms.
T52=52 mm width special tape in box; R52=52 mm width special tape & reel.
T76=76 mm width special tape in box; R76=76 mm width special tape & reel.
Letter "PA" indicates radial type lead taping; Letter "PM" indicates radial type lead taping.
Remark :RSN & RSS Series Resistors are RoHS & Halogen Free Compliant.
3. Rated Power:
Rated power is the value of Max load power specified at the ambient temperature of 70℃, and shall meet
the functions of electrical and mechanical performance. When the ambient temperature surpasses above
mentioned temperature, the value declines as per following DERATING CURVE.
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3.1 Rated Voltage:
It is calculated through the following formula:
E P*R
where E: rated voltage (V)
P: rated power (W)
R: nominal resistance value (Ω )
However, in case the voltage calculated exceeds the maximum load voltage, such the maximum load
voltage shall be regarded as its rated voltage, means whichever less.
4. Dimension and structure:
4.1 Dimension:
Unit: mm
TYPE
D±1
L±1
H±3
d±0.1
Resistance Range
Max Working
Voltage
Max Overload
Voltage
RSS
RSN
1/2W
1/4W
2.6±0.5
6.8
28
0.6
0.22Ω ~33KΩ
250V
400V
1/2W
3
9
28
0.65
0.22Ω ~33KΩ
300V
400V
3.5
9
28
0.65
0.22Ω ~50KΩ
350V
600V
1W
2W
1W
4.5
11
28
0.8
0.22Ω ~50KΩ
350V
600V
3W
2W
5
15
28
0.8
0.22Ω ~50KΩ
350V
600V
5W
3WL
8.5
24
38
0.8
0.22Ω ~100KΩ
500V
800V
6W
4W
8.5
32
33
0.8
0.22Ω ~150KΩ
500V
800V
7W
5W
8.5
41
38
0.8
0.22Ω ~200KΩ
750V
1000V
10W
7W
8.5
53
38
0.8
0.22Ω ~200KΩ
800V
1500V
Notes:1. too low or too high ohmic values can be supplied only case by case.
2 .if high resistance values are required, we suggest using RDN series.
3. 0.22Ω ~9.1Ω are using alloy film.
4.2 STRUCTURE:
4.2.1 Ceramic Rod:
It is made of Forsterite imported.
4.2.2 Terminal:
Terminal is to be firmly connected with resistors element, both electrically and mechanically,
and allow easy soldering.
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METAL OXIDE FILM RESISTORS, FLAMEPROOF
4.2.3 Coating:
Coating is done by light gray flameproof paint for RSN type and dark gray flameproof for RSS
(resistant to 800℃) which is solid enough to be free from looseness, crack and easy breakage. It
is also resistant to cleaning and industrial solvents, and the paint shall be limited within 2mm of
lead wires from resistor body.
4.2.4 Marking:
Marking is made on resistors surface, by four color coding; 1st, 2nd, 3rd: nominal resistance,
4th: tolerance. or marked with type of resistor, rated wattage, nominal resistance, tolerance
and maker's trade mark (TY-OHM).
5. Operating Temperature Range: -55℃~155℃
6. Mechanical Performance:
6.1 Terminal tensile:
To fix the resistor body, a static load of 2.5kg. (under 1/2W:1kg.)is to be gradually applied into the
terminal for 10 seconds without causing any looseness and fall.
6.2 Twist withstand:
To bend the lead wire at the point of about 6mm from resistor body to 90°, then catch the wire at 1.2
±0.4mm apart from the bent point end and turn it (clockwise) by 360 degrees perpendicular to the
resistor axis at speed of 5 seconds per turn, and do the same counterclockwise again which constitute
a whole turn. Repeat the turn 2 times without causing any break and looseness.
7. Electrical Performance:
7.1 Resistance Temperature Coefficient:
It shall be within ±300ppm/℃.
6
T.C (ppm/℃) =〔(R2-R1)÷R1〕×〔1÷(T2-T1)〕×10
where
R1: resistance value at reference temperature
R2: resistance value at test temp.
T1: reference temp.
T2: test temp.
7.2 Temperature Cycle:
Following temp. cycles are to be made 5 times and then put at room temp. for one hour, the resistance
value change rate between pre-and-post test shall be within ±1%
Steps
st
1 step
nd
2 step
rd
3 step
th
4 step
Temperature(℃)
-55 ± 3
Room temp.
155 ± 3
Room temp.
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Time (minutes)
30
3
30
3
METAL OXIDE FILM RESISTORS, FLAMEPROOF
7.3 Short Time Over Load:
When the resistors are applied 2.5 times as much as rated voltage for 5 seconds continuously, it shows
no evidence of arc, flame...etc. Removing the voltage and place the resistors to the normal condition
for 30 minutes, the resistance value change rate between pre-and-post test shall be within ±1%(RSS
= ±2%).
7.4 Insulation Character :
Resistors are located in a V-shaped metal trough. Using the DC 100V or 500V megger instrument 2
poles to clutch either side of lead wires and metal trough, measuring the Insulation Resistance which
shall be over 1000MΩ .
7.5 Voltage Withstanding:
Resistors are located in a V-shaped metal trough. Applying Max Working Voltage for one minute and
should find no physical damage to the resistors, such as arc, char ...etc.
7.6 Load Life:
The resistors arrayed are sent into the 70℃ oven, applying rated voltage at the cycle of 1.5 hours ON,
0.5 hour OFF for 1000+48
-0 hours in total. Then, after removing the voltage, take the resistors out of the
oven and left under normal temp. for one hour cooling. The resistance value change rate between
pre-and-post test shall be within ±5%.
7.7 Moisture-proof Load Life:
The resistors arrayed are placed into a constant temp./humidity oven at the temp. of 40 ±2℃ and the
humidity of 90~95%, then rated power is applied for 1.5 hours and cut off for 0.5 hour. The similar
cycle will be repeated for 500+24
-0 hours in total (including cut-off time). Then remove the voltage,
taking the resistors out of the oven and leaving them at room temp. for one hour. The resistance value
change rate between pre-and-post test shall be within ±5%. There also shall be no evidence of
remarkable change on appearance, and the marking shall not be illegible.
7.8 Solder-ability:
The leads with flux are dipped in a melted solder of 235 ±5℃ for 2 seconds, more than 95% of the
circumference of the lead wires shall be covered with solder.
7.9 Resistance to Soldering Heat:
Two leads are together dipped in a melted solder of 270 ±5℃ for 10 ±1 seconds, or 350 ±10℃ for
3.5 ±0.5 seconds, Then remove the resistors and leaving them at room temp. for one hour. The
resistance value change rate between pre-and-post test shall be within ±1%.
7.10 Nonflammability:
The resistors are applied the power of 16 times the rated wattage for 5 min. and shall not get flame.
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8. Others:
8.1 MG Form:
Unit: mm
RSS
RSN
D±1
L±1
P
H
h±1
A±0.1
B±0.05
C±0.2
1/2W
3
9
12.5±1.5
7±1
4.5
0.23
0.8
1.2
3.5
9
15±1.5
7±1
4.5
0.23
0.8
1.2
1W
2W
1W
4.5
11
15±1.5
7±1
4.5
0.25
1
1.4
3W
2W
5
15
20±2
10±2
4.5
0.25
1
1.4
8.2 F Form:
Unit: mm
RSS
RSN
1W
D±1
L±1
A +1/-0.5 Applicable
3.5
9
3.5
F1~F4
2W
1W
4.5
11
3.5
F1~F4
3W
2W
5
15
3.5
F1~F4
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METAL OXIDE FILM RESISTORS, FLAMEPROOF
8.3 Packing:
8.3.1 Taping Specifications:
Unit: mm
RSS
RSN
Package
A
B
C ± 1
D Max
E Max
≦1W
≦1/2W
T/B, T/R
52 ± 1
5 ± 0.5
6
0.6
1.2
T52,R52
52 ± 1
5 ± 0.5
6
0.6
1.2
2W
1W
T/B, T/R
63 ± 1
5 ± 0.5
6
0.6
1.2
T/B, T/R
63 ± 1
10 ± 1
6
0.6
1.2
T52, R52
52 ± 1
10 ± 1
6
0.6
1.2
76 ± 1.5 10 ± 1
6
0.6
1.2
3W
2W
T76,R76
8.3.2 Tape in Box:
Unit: mm
QTY
RSS
RSN
Type
a
b
c
PER BOX
1/2W
1/4W
T/B
5,000
75
100
255
1/2W
T/B
1,000
75
55
255
T/B
1,000
75
55
255
T52
1,000
75
55
255
T/B
1,000
85
105
260
T/B
1,000
100
110
265
T52
1,000
75
100
255
T76
1,000
105
114
265
1W
2W
3W
1W
2W
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METAL OXIDE FILM RESISTORS, FLAMEPROOF
8.3.3 Tape & Reel:
Unit: mm
QTY
RSS
RSN
Type
A
B
C
D
E
F
PER REEL
1/2W
1/4W
T/R
5,000
285
310
75
80
295
295
1/2W
T/R
5,000
305
330
75
90
310
310
T/R
2,500
285
310
75
80
295
295
R52
2,000
285
310
75
80
295
295
T/R
2,000
285
310
75
80
295
295
T/R
1,000
285
310
75
80
295
295
R52
1,000
285
310
75
80
295
295
R76
1,000
285
310
90
105
295
295
1W
2W
3W
1W
2W
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METAL OXIDE FILM RESISTORS, FLAMEPROOF
8.3.4 Radial type lead taping(PA):
Unit: mm
RSS
RSN
1/2W
1W
2W
3W
1/4W
1W
2W
P
±1
12.7
12.7
12.7
12.7
P0
±0.3
12.7
12.7
12.7
12.7
P1
±0.7
3.85
3.85
3.85
3.85
P2
±1
6.35
6.35
6.35
6.35
F
±0.8
5
5
5
5
8
W
W1
±0.5 ±0.5
18
9
18
9
18
9
18
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H1
H0 φ D0
max ±0.5 ±0.2
32
16
4
32
16
4
38
16
4
38
16
4
A
±1
6.8
9
11
15
φd
±0.1
0.6
0.65
0.8
0.8
φD
±1
2.6±0.5
3.5
4.5
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METAL OXIDE FILM RESISTORS, FLAMEPROOF
8.3.5 Radial type lead taping(PM):
Unit: mm
RSS
RSN
1W
2W
3W
1W
2W
F
+0.8/-0.2
7.5
7.5
7.5
P
±1
30
30
30
P0
±0.3
15
15
15
P1
±1
7.5
7.5
7.5
P2
±0.8
3.75
3.75
3.75
H
+1/-0
6.5
7.5
8.5
9
H0
±0.7
19
19
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A
max.
14.5
17.5
21
W
W1
±0.5 ±0.5
18
9
18
9
18
9
φD
±1
3.5
4.5
5
φ D0
±0.2
4
4
4
φd
±0.1
0.65
0.8
0.8
L
±1
9
11
15