"SURE" BRAND WIRE WOUND RESISTOR - SCA SERIES
CERAMIC ENCASED AXIAL LEAD TYPE - Professional Grade

Ceramic Encased Axial Lead Type, Wire Wound Resistor, Professional Grade Resistor, Thane, India

Features: 

• High Power dissipation in small volume
• High surface insulation property
• Completely fire proof and welded construction
• Available in PCB type and capacitor type terminals
• Formed leads available on request
• Low inductance type available on request
• Long leads also available

General Specifications:

DESCRIPTION SCA03 SCA04 SCA06 SCA09 SCA12 SCA20
Resistance range, Series And tolerance (1)

10 %

5  %

E24 Series

0.01 W - 0.05 W

0.06 W - 100 KW

Maximum dissipation at Tamb = 40 C

03 W

04W

06 W

09 W

12 W

20 W

Maximum permissible voltage

(volts DC or RMS)

V =√ (Pn x R)

Insulation voltage

> 2000 V

Temperature coefficient. (2)

R < 10 W: 0 to +600ppm/C

Operating temperature

R ≥  10 W: -100 to +150ppm/C

- 55 C to + 275 C

Stability DR/Rmax after:

Lead, 1000 hours

Climate tests

Short time overload

5.0% + 0.1 W 3.0% + 0.05 W 4.0% + 0.05 W


(1) Tolerances, 1% and 3% available on request
(2) Temperature coefficient, 30, 50 and 90ppm/C, available on request

Mechanical Data:



Table 1

TYPE

L

D

d

SCA03 15 1.5 7.5 0.8 0.81 0.03
SCA04 25 1.5 7.5 0.8 0.81 0.03
SCA06 25 1.5 9.5 0.8 0.81 0.03
SCA09 38 1.5 9.5 0.8 0.81 0.03
SCA12 38 1.5 11.0 0.8 0.81 0.03
SCA20 50 1.5 11.0 0.8 0.81 0.03

Dimensions in mm

Construction

SCA: The resistor element is a resistive wire, which is wound, on ceramic rod. Tinned copper leads are connected to the caps by welding. The resistor body is housed in a rectangular ceramic case with a special inorganic potting which is non-flammable, will not melt even at high overloads and is resistant to most commonly used cleaning solvents and moisture.

Electrical Characteristics

DERATING
The power that the resistor can dissipate depends on the operating temperature; see below

Fig - Maximum dissipation (Pmax) in percentage of rated power as a function of the ambient temperature (Tamb)

Applications:

The SCA Series is recommended for the use where occasional overload is upto 125% for long time [upto 2 Hrs.] are probable. This Series is also preferred for aesthetic value. The fusible resistors are also available in this series.

Test and Requirements

Essentially all tests and requirements present in table below follow the schedule of IEC standard publication 60115-1, 60115-4 and 60068.

TEST

PROCEDURE

REQUIREMENTS

Insulation resistance

500 V (DC); during 1 minute

V-block method

Rins min 100 MW

Voltage proof on

insulation

 

1000 V (RMS); during

1 minute V-block method.

No breakdown or flashover

Temperature

Coefficient

Between

-55 C at +275 C:

R < 10 W

R ≥10W

0 to +600ppm/C

+ 150 to - 100ppm/C

Short time overload

5 times the rated wattage for 5 sec

DR/Rmax: 2% +0.05W

Robustness of terminations:

 

Tensile all samples

 

 

Bending half number of samples

 

Torsion other half

Number of samples

 

 

 

Load 10N; 10 s

 

 

Load 5N; 4 x 90

 

 

3 x 360 in opposite

Directions

No visible damage

DR/Rmax; 2% + 0.05W

Solderability

(after ageing)

16h at 155 C, leads

Immersed in flux 600, leads immersed 2 mm for 2 0.5 s in a solder bath a 235 5 C

Good tinning;

No damage

DR/Rmax; 0.5% 0.05W

Resistance to Soldering heat

Thermal shock; 3s, 350 C;

6mm from body

DR/Rmax; 4% + 0.05W

Rapid change of

temperature

30 minutes at -55 C and 30 minutes at + 275 C;

5 cycles

No visual damage

DR/Rmax; 5% +0.05W

Climate sequence:

 

Dry heat

 

Damp heat

(accelerated)

1st cycle

 

Cold

 

Damp heat (accel) remaining cycles

 

 

16h, 275 C

 

24h; 25 C to 55 C;

90% to 98% R.H.

 

 

2h; - 65 C

 

6 days; 55 C;

90% to 98% R.H;

DR/Rmax; 3%+ 0.05W

Damp heat

(steady state)

56 days; 40 C;

90 to 95% RH

Loaded with 0.01 Pn

DR/Rmax; 5% +0.05

Endurance

40 C

1000 hours load with Pn or Vmax 1.5h ON 0.5h OFF

No damage

DR/Rmax  5% +0.1W