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Document Number: 50019
Revision12-Jan-04
For technical questions, contact sfer@vishay.com
Adjustable Wirewound Enamelled Resistors
”B” Ring
The ceramic tubular core ensures high dissipation capacity and excellent resistance to thermal shock and overload. The resistor
winding is evenly coiled on the core and protected by an enamel coating. A longitudinal opening provides for one or more
electrical connections by means of sliding collars equipped with a tongued connector.
WELDED STAINLESS STEEL 304 L BAND “B”
WELDED STAINLESS STEEL 304 L COLLAR “AN” TYPE 1
SCREWED STAINLESS STEEL 304 L “CS” TYPE 1
FEATURES
• 21 Watt to 180 Watt at 25°C
• NF C 93-214
- RBA 13 x 70
- RBA 20 x 117
- RBA 25 x 168
DIMENSIONS in millimeters
*Also with CS and CR collars. See RW data sheet.
RA MODEL
Connection
A ± 2
Ø B max.
Ø C min.
13 x 70
AN-B*
70
16
5
16 ± 0.5
7
10.5
–
19.5
24
–
56 ± 2
–
24.5
–
–
24 ± 0.5
4.2
6.35
–
20 ± 0.5
34.5 ± 1
3.5
40
16 x 94
AN-B
94
19.5
9
17.5 ± 0.5
8
12
–
23
29.5
–
78 ± 2
–
28
–
–
26.5 ± 0.5
4.2
6.35
–
21 ± 0.5
38 ± 1
5
70
25 x 138
AN-B-CS
138
28
12
23.5 ± 1
8
15
27
27.5
34
199
117 ± 2
169
38.5
50
24
33.5 ± 1
5.7
9
6.5
28.5 ± 1
51 ± 1.5
6
200
25 x 168
AN-B-CS
168
28
12
23.5 ± 1
8
15
27
27.5
34
229
147 ± 2
199
38.5
50
24
33.5 ± 1
5.7
9
6.5
28.5 ± 1
51 ± 1.5
6
225
30 x 250
AN-B-CS
250
33
17
26 ± 1
8
18
30
30
36.5
317
227 ± 2.5
287
43.5
60
25
36 ± 1
5.7
13
9
33 ± 1
55 ± 1.5
5
415
20 x 117
AN-B
117
23
9
21 ± 0.7
8
14
–
25
31.5
–
98 ± 2
–
33
–
–
31 ± 0.7
4.2
6.35
–
24 ± 0.7
42 ± 1
6
116
DIMENSIONS in millimeters
D
E
F
H ± 1
J max
K max
L
M
N
O max
P ± 1.5
Q ± 0.5
R
S
T
U ± 0.5
V
X
Z approx
Average unit
weight in g
+ 0.5
+ 0
+ 0.5
+ 0
- 0
- 4
- 0
- 4
A
26
ØB
P
H
Q
45°
U
L
N15
A
Ø4.2
F
ØBE
DO
ØC
J
K
45°
M
ØC
ØB
A
ØS
V
ZT
X
R
45°
Document Number: 50019
Revision 12-Jan-04
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68
RA
Vishay Sfernice
For technical questions, contact sfer@vishay.com
*1% of total resistance and 2% between sliding collar and fixed connection.
TESTS CONDITIONS REQUIREMENTS
TYPICAL VALUES AND DRIFTS
Short Time Overload 10Pr 5s
Voltage < 6000V 2% or 0.05
3% or 0.05
Insulation resistance > 100M
2% or 0.05
Insulation resistance > 100M
2% or 0.05
2% or 0.05
1%* or 0.05
1% or 0.05
5%
0.5%
1%
0.5%
0.5%
0.25%
0.5%
0.25%
1.5%
– 55°C + 200°C
5 cycles
56 days
95% R.H.
Load at Pr
followed by exposure at – 55°C/15
200N ± 10N
55/10
1000 hours at Pr
25°C
90 /30
Climatic Sequence
Humidity
(Steady State)
Thermal Shock
Resistor Strength
Vibration
Terminals Strength
Load Life
PERFORMANCE
MODEL
AND TYPE
Additional
sliding collar 1
RA
13 x 70
1
RA
16 x 94
1
RA
20 x 117
2
RA
25 x 138
3
RA
25 x 168
4
RA
30 x 250
MAXIMUM ADDITIONAL COLLARS
ADMISSIBLE RATED AMPERAGE
This must in all cases be less than:
In = Pr (W)
Rn ( )
SLIDING COLLAR
Resistors are normally supplied with 1 sliding collar fi tted and locked in a specifi c position.
Additional collars can be supplied and adjusted at the factory to special order (on request).*
*Quote ohmic value and tolerance of each resistance section, and Rn value.
√
Adjustable Wirewound Enamelled Resistors
MECHANICAL SPECIFICATIONS
Mechanical Protection vitreous enamel
Resistive Element Ni-Cr wire
Connections B band
AN or CS collar
Average Unit Weight 40 to 415g
ENVIRONMENTAL SPECIFICATIONS
Temperature Limits – 55°C + 350°C
Climatic Category – 55°C/+ 200°C/56 days
Resistance Range 33 to 22k
(E6-E24 series)
Tolerance
Standard ± 10%
Power Rating 21W to 180W at 25°C
Temperature Coeffi cient + 75ppm/°C (typical)
ELECTRICAL SPECIFICATIONS
RA STYLE
Designation NF C 93-214
13 x 70
RBA 13 x 70
13W
21W
33 3.9k
16 x 94
–
–
35W
68 3.9k
20 x 117
RBA 20 x 117
25W
50W
100 4.7k
25 x 138
–
–
75W
150 6.8k
25 x 168
RBA 25 x 168
50W
120W
220 10k
30 x 250
–
–
180W
330 22k
Power Rating
NF C 93-214
at 25°C
Maximum Power
Rating at 25°C
SPECIAL FEATURES
Ohmic Range
(E6, E24 series)
AN Traction 40Ncm
B Torque 60Ncm
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Vishay Sfernice
Document Number: 50019
Revision12-Jan-04
For technical questions, contact sfer@vishay.com
POWER RATING CHART
AMBIENT TEMPERATURE IN DEGREES CELSIUS
% RATED POWER
100
75
50
25
0
0 50 100 150 200 250 300 350
TEMPERATURE RISE
RATED POWER IN WATTS
HOT SPOT TEMPERATURE IN °C
400
300
200
100
0
10 100 1000
RA 13 x 70
RA 16 x 94
RA 20 x 117
RA 25 x 138
RA 25 x 168
RA 30 x 250
MODEL
RA
STYLE
20 x 117
SPECIAL
DESIGN
In option
OHMIC
VALUE
6.8k
Custom items are subject
to extra-charge and min. order.
Please see price list.
TOLERANCE
± 10%
ADDITIONAL
SLIDING
COLLAR
4 SUP. C.
MARKING
SFERNICE trademark, model, style, NF style (if applicable) ohmic value (in ), tolerance (in %), manufacturing date.
ORDERING INFORMATION
Adjustable Wirewound Enamelled Resistors
CONNECTIONS
AN
