RSSD
Adjustable Wirewound Vitreous Resistors
Low Ohmic Values (0.10 Ω available) Vishay Sfernice
Document Number: 50020 For technical questions, contact: sfer@vishay.com www.vishay.com
Revision: 25-Jul-07 71
MECHANICAL SPECIFICATIONS
Mechanical Protection
Vishay Sfernice Special cement
Resistive Element nickel alloy wire
Connections AN collars
CS supporting collars
Average Unit Weight 10 to 1350 g
ENVIRONMENTAL SPECIFICATIONS
Temperature Limits - 55 °C + 450 °C
Climatic Category - 55 °C/+ 200 °C/56 days
ADDITIONAL TAPPINGS
Are supplied with their adjustable collars fastened but not set to any specific value. Please note that, on request, all tappings can
be adjusted by VISHAY SFERNICE. For adjustment purposes we would need to be advised of the ohmic values, and tolerances
of the sections in successive order in addition to their sum Rn.
The permissible maximum value for an adjustment should take into account the possible negative tolerance of Rn.
Please consult VISHAY SFERNICE regarding the acceptable tolerance.
RECOMMENDATIONS FOR USE
Maximum Current Strength:
The ohmic value and the power decrease as the connections are brought together. To avoid overload, the maximum current
strength that is permissible for Rn should never be exceeded:
Imax =
ELECTRICAL SPECIFICATIONS
Resistance Range 0.12 Ω to 560 Ω
(E12 series)
Standard Resistance R ≥ 10 Ω ± 5 %
Tolerance 1 Ω ≤ R ≤ 10 Ω ± 10 %
0R1 ≤ R < 1 Ω ± 20 %
Power Rating 14 W to 600 W at 25 °C
Temperature Coefficient + 75 ppm/°C (typical)
PERFORMANCE
TESTS CONDITIONS REQUIREMENTS
TYPICAL
VALUES
AND DRIFTS
Short Time Overload 10 Pr during 5 s 2 % 1 %
Climatic Sequence - 55 °C + 200 °C
5 cycles 3 % 1 %
Thermal Shock Load at 100 % Pr
followed by cold - 55 °C/15
2 %
or 0.05 Ω1 %
Load Life 90/30 cycle
1000 h at Pr at + 25 °C 5 % 1.5 %
SPECIAL FEATURES
RSSD TYPE 8 × 34 10 × 50 13 × 70 16 × 94 20 × 117 25 × 138 25 × 168 30 × 250 40 × 370 50 × 373
Power Rating
at 25 °C
Continuous 16 W 25 W 42 W 70 W 100 W 140 W 200 W 280 W 450 W 600 W
Reduced 14 W 22 W 38 W 62 W 90 W 125 W 170 W 240 W 360 W 450 W
Resistance Ohmic Range
(E12, E24 Series)
with 1 Tapping
0.12 Ω
10 Ω
0.12 Ω
22 Ω
0.12 Ω
43 Ω
0.33 Ω
75 Ω
0.22 Ω
100 Ω
0.10 Ω
150 Ω
0.12 Ω
220 Ω
0.22 Ω
360 Ω
0.47 Ω
470 Ω
0.68 Ω
560 Ω
Maximum Number
of Additional
Tapping
0 1 1 1 1 1 2 2 4 4
Reduction % of Ohmic
Value by Tapping 23 21 14 11 10 8 6.5 6 5.7 5.7
Pr/Rn