Cemented and enamelled wiredound resistors model SMR

Professional resistors with a regulation collar, with fine electrical and mechanical characteristics, indicated for use where high power is required, along with safe operation and durability.
The external lining is protected by a layer of vitreous enamel.
The resistive element consists of wire in Ni-Cr alloy or twisted constantan, on a cylindrical support in extremely pure ceramic material.
The resistors may be produced with different terminations depending on the model and ohm value, standard banner type B, with fast-on and pattern type terminals, and in versions with off-standard tolerances.
The adjustment collar enables the user to establish an intermediate value. The stability of the contact is guaranteed up to the maximum surface temperature of 350° C

ELECTRICAL CHARACTERISTICS

· Standard tolerance: +15%
· Temperature coefficient ≤ 100 ppm/°C
· Insulation resistance > 100 Mohm (500 Vdc)
· Max operating temperature: 350 °C

MAXIMUM LOAD LIMIT

NOTE: For adjustable resistors it must be born in mind that the nominal power is understood as applied to the entire resistor, if only part of it is under tension, the power applied must be reduced in proportion to the part that is not used.
The nominal power Pn shown in the table refers to resistors placed horizontally and free in naturally circulating air, with an environmental temperature of 25° C.
With forced ventilation the nominal power dissipation capacity of the resistor increases as a function of the air speed.

STANDARD CHARACTERISTICS


 
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