www.vishay.com
39
RWM
Vishay Sfernice
Document Number: 50008
Revision 17-Nov-05
For technical questions, contact sfer@vishay.com
PERFORMANCE
TESTS
Short Time Overload
Temperature Cycling
Humidity (Steady State)
Terminal Strength
Load Life
CONDITIONS REQUIREMENTS
± (2 % + 0.1 Ω)
± (1 % + 0.05 Ω
)
± (5 % + 0.1 Ω
)
± (1 % + 0.05 Ω
)
± (5 % + 0.1 Ω
)
± (0.5% + 0.05 Ω)
±
(
0.5 % + 0.05 Ω)
±
(
0.5 % + 0.05 Ω)
±
(
0.1 % + 0.05 Ω)
±
(
1.5 % + 0.05 Ω)
10 Pr during 10 s.
25 °C ambient
– 55 °C + 200 °C
56 days
40 °C Ambient - R.H. 95 %
Tensile test: 20 N
2 successive bending
2 full rotations of 180°
1000 h at Pr
90/30 Cycle
25 °C ambient
CECC 40201
TYPICAL DRIFTS
OVERLOAD
Heavy overloads can be endured in the form of short pulses < 0.1 s. Particular requirements should be submitted to Vishay
Sfernice, specifying peak voltage, cycle and environmental conditions.
RECOMMENDATIONS FOR USE
Since these components are high dissipation power resistors, customers are advised to use a high melting point solder.
For low ohmic values, the measurement becomes critical and the connecting wires resistance is to be included. The value
is measured at 5mm from the resistor body.
Group Mounting
In a still atmosphere, a distance between axes equal to fi ve times the resistor’s diameter is recommended.
Cabinet Mounting
• Unventilated box: dissipation should be reduced (see dimensional drawing).
• Forced ventilation: if conditions are appropriate, dissipation may be doubled or even trebled.
• In any case: the surface temperature at the hottest point should not exceed 450 °C.
These aspects should be considered by the end user.
Enamelled Wirewound Power Resistors
Axial Leads
ELECTRICAL SPECIFICATIONS
Tolerance Standard ± 5 %
On request ± 1 % to ± 10 %
Temperature Coeffi cient + 75 ppm/°C typical
Dielectric Withstanding Voltage NF EN 140000 500 VRMS - 1 minute - 10 mA
Inductance non inductive (Ayrton-Perry)winding available