AC03 Safety (AC03..CS)

www.vishay.com

Vishay Draloric

Revision: 24-May-12

1

Document Number: 28861

THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT

Axial Cemented Wirewound Safety Resistor

FEATURES

• Surge voltage capability: 2 kV (30 pulses/

15 min) as per IEC 61000-4-5. Higher surge

capability on customer request.

• Fusing time < 30 s for 45 W overload

• Tinned Cu wire terminations

• Ohmic range: 10

 to 100 , 5 %

• Special cement coating for immediate interruption without

applied

• Specially designed for applications in electric appliances,

energy meters

• Material categorization: For definitions of compliance

Vishay has introduced special version of AC03 wirewound resistors to be used as fusible safety resistor (or, AC mains input

resistors). It uses specially selected resistive winding wire and special coating material to ensure safe and silent fusing operation

in overload conditions. The resistor fuses “without a bang” when AC mains voltage is applied. At the same time, it acts as a

in-rush current limiting resistor for the normal operation. The specially developed lacquer coating matches the thermal and

electrical insulating properties of standard silicone cement. This allows designers to more easily meet the requirements of UL

approval, whilst eliminating the need to put additional fuses in series with the input resistor.

In the conventional wirewound resistor, ceramic rod at the resistor's core acts as a heat sink for the wire element. This can delay

fusing, resulting in high temperatures to fragment the coating and ionize the air near the fusing spot. If ionization occurs close

to the cap edge and at a voltage peak in the mains cycle, it can initiate a momentary flashover outside the component body,

releasing far more energy than is required to fuse the wire element. Although the opening of the circuit is safe for most

applications, it can be with a “bang” with splattering of cement coating. This is un-safe operation and not desirable.

AC03 Safety resistor has new coating material and process to give silent and safe fusing. It can absorb thermal stresses without

fragmenting or burning of resistor coating.

Note

(1)

Resistance value to be selected for ± 10 % tolerance from E12 and for ± 5 % from E24 series

STANDARD ELECTRICAL SPECIFICATIONS

MODEL

POWER RATING

W

POWER RATING

W

LIMITING

VOLTAGE



TCR = ± 200 ppm/K

TOLERANCE

± %

AC03

3

2.5

10 to 100

5

P x R