Flammability

The resistor coating is UL94-V0 rated and will not burn or emit incandescent particles under any condition of applied

temperature or power overload.

Marking

EMC resistors are colour coded with five bands. Four of the bands indicate value and tolerance in accordance with

IEC62. Parts with 20% tolerance have no fourth band. A fifth yellow band denotes constant voltage fusibility.

Performance Data

Maximum

Load at Rated Power: 1000hrs @ 70

°C

∆R%

5

Shelf life: 12 months at room temperature

∆R%

2

Derating from rated power at 70

°C

Zero at 155

°C

Climatic

∆R%

3

Climatic Category

50/155/56

Temperature rapid change

∆R%

0.5

Resistance to solder heat

∆R%

0.5

Pulse Performance

Fusing Performance

General Note

Welwyn Components reserves the right to make changes in product specification without notice or liability.

All information is subject to Welwyn’s own test data and is considered accurate at time of print.

©Welwyn Components Limited

Welwyn Electronics Park, Bedlington, Northumberland, NE22 7AA, England. Tel: 01670 822181 Fax: 01670 829465 Web: www.welwyn-tt.com

Single Rectangular Pulse

1

10

100

1000

10000

0.01

0.1

1

10

100

1000

10000

Pulse Duration (ms)

A subsidiary of TT electronics plc

IEC61000-4-5 1.2/50

µs Pulse

0

100

200

300

400

500

600

700

0

10

20

30

40

50

60

70

Value (Ohms)

EMC resistors fuse open circuit at overload powers

exceeding 40W within the time indicated on the

Fusing Characteristic. Their fusing performance at

lower overload powers is not specified.

EMC resistors fuse safely in the event of a 115Vrms /

240Vrms overload (line / mains short circuit

condition) without burning or emitting incandescent

particles.

After fusing, the resistance is at least 100 times

greater than the original nominal value.

Fusing Characteristic

(Constant Voltage)

0

10

20

30

40

50

60

0

20

40

60

80

100

Initial Power (W)

(4R7-8R2)

(10R-68R)