Document Number: 50008 For technical questions, contact: sfer@vishay.com
www.vishay.com
Revision: 22-Dec-11 89
RWM
Enamelled Wirewound Power Resistors
Axial Leads
Vishay Sfernice
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE.
THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
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 5 mm from the resistor body.
Group Mounting
In a still atmosphere, a distance between axes equal to five
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.
PERFORMANCE
CECC 40201 - EN 140-201
TYPICAL DRIFTS
TESTS CONDITIONS REQUIREMENTS
Short Time Overload
10 P
r
during 10 s
25 °C ambient
± (2 % + 0.1 Ω) ± (0.5 % + 0.05 Ω)
Temperature Cycling
(5 cycles)
- 55 °C + 200 °C ± (1 % + 0.05 Ω) ± (0.5 % + 0.05 Ω)
Humidity (Steady State)
56 days
40 °C ambient - R.H. 95 %
± (5 % + 0.1 Ω) ± (0.5 % + 0.05 Ω)
Terminal Strength
Tensile test: 20 N
2 successive bending
2 full rotations of 180°
± (1 % + 0.05 Ω) ± (0.1 % + 0.05 Ω)
Load Life
1000 h at P
r
90’/30’ cycle
25 °C ambient
± (5 % + 0.1 Ω) ± (1.5 % + 0.05 Ω)
ELECTRICAL SPECIFICATIONS
Tolerance Standard ± 5 %
On request ± 1 % and ± 2 %
Temperature Coefficient + 75 ppm/°C typical
Dielectric Withstanding Voltage NF EN140000 500 V
RMS
- 1 min - 10 mA
Inductance Non inductive (Ayrton-Perry) winding available
