FRC Series

FUSIBLE RESISTORS
  • Ceramic encased bath tub type - with flame retardant moulding.
In order to meet the growing demand worldwide for resistors to fuse or blow as a safety measure, HTR can provide fusible resistors which fuse or blow if they are subjected to an abnormal spike of voltage / current.

Physical configuration
BATH TUB TYPE -please refer to HTR type C1 to C10

Electrical and Environmental Characterstics/Data

 
Test Performance
Resistance tolerance ± 10% [K]: ± 5% [J] [ < 1ohms ± 0.05 ohms]
Di-electric withstanding voltage Max DR ± [ 2% ± 0.05 ohms]
Insulation resistance >1000 M [ Dry]
Temperature co-efficient ± 550 ppm/°C
Short time overload Max D R ± [2%+ 0.05 ohms]
Moisture resistance Max D R ± [5%+ 0.05 ohms]
Load life Max D R ± [5%+ 0.05 ohms]
Ambient operating temperature range -25 °C to + 155° C
Flame test Specification laid down by UL have been met satisfactorily
NOTE
Contrary to popular belief, fusible resistors are not standard resistor types and each type of fusible resistor must be tailor designed to suit a particular application.
 
 
ORDERING INFORMATION :
In order that we can design a fusible resistor suitable to your needs, we need the following data from you :-
  • Power rating in terms of watts.
  • Resistance in ohms.
  • Tolerance.
  • Maximum continuous working voltage across the resistor, at which the resistor must continue to function.
  • Fusing voltage - The voltage at which the resistor must fuse or blow.
  • Fusing time - The duration within which the resistor must fuse or blow, on being subjected to the fusing

    • voltage.
  • In case, lead preforming is required, we need a drawing. This service is provided, upon a minimum

    • order of 5000 pieces.
    These resistors can also be provided in taped form.

NOTE :
Generally speaking as per international standards, a fusible resistor fuses on being given fusing voltage from instantaneously to 45 seconds without any flame.

At HTR if no special data is provided, we assume that if a fusible resistor is ordered, it should fuse on being given voltage calculated at 16 times power from instantaneously to 45 seconds.

Precautions to be taken : Before conducting this test the voltage must be correctly set / adjusted by first using a dummy piece which should then be discarded.
 

TYPICAL APPLICATIONS
As mentioned previously a fusible resistor is a tailor made dual purpose component -
    (a) In normal conditions it functions as a resistor.
    (b) In high overload conditions it acts as a fuse/safety device.
 

Eurocap International Limited.   138 High Street,  Cheshunt,  Herts,  EN8 0AP  England.
Tel    +44 (0)1992 625407      Fax   +44 (0)1992 625420
Email eurocap@dial.pipex.com