Aluminium Housed

Wirewound Resistors

Performance Data

WH5 - 50

WH100 - 300

Actual

CECC 40203-006

Requirements

Maximum

Typical

Maximum

Load at commercial rating: 1000hrs at 25°C

ΔR%

1

1

0.4

2

Load at CECC rating: 1000hrs at 25°C

ΔR%

1

1

0.4

N/A

Dry heat: 1000hrs at 200°C

ΔR%

1

1

0.4

2

Derating from 25°C

Zero at 200°C, see derating graph

Short-term overload

ΔR%

1

1

0.2

Climatic sequence

ΔR%

1

1

0.4

Climatic category

55/200/56

Long-term damp heat

ΔR%

1

0.5

0.2

Temperature rapid change

ΔR%

0.25

0.25

0.1

0.25

Resistance to solder heat

ΔR%

0.25

0.25

0.05

WH100: 0.5

Vibration and bump

ΔR%

0.25

0.25

0.025

Noise (in decade of frequency)

μV/V

Not specified

0

0

0

Insulation resistance

ohms

1G min

10G min

Pulse and overload performance

Not specified

See graphs

Note: A 0.05 ohm addition is to be added to the performance of all resistors < 10 ohms.

Application Notes

After soldering care should be taken to ensure that there are no flux residues on the end faces of the moulding

compound, otherwise insulation resistance will be reduced. The minimum surface tracking distances from termination

to casing are shown in the Physical Data tables as dimension Dt.

It is recommended that the resistor base should be coated with heatsink compound before mounting to obtain the

stated operating characteristics. The heatsink compound increases thermal conductivity to the heatsink.

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

1

10

0.1

1

10

100

1000

Overload Duration (s)

WH5&10

WH100-300

WH25-300

WH5-50

0.1

1

10

100

1000

10000

0.01

0.1

1

10

100

1000

10000 100000

Value (ohms)

WH5

WH10

WH25

WH50

WH100

WH200

WH300

Pulse and Overload Performance

For short durations of

≤0.1s the energy graph should

be used. For longer durations the overload graph

applies.

Terminations

WH5-100

Material

Pb-free solder dipped, copper clad steel

Strength

The terminations meet the requirements

of IEC 68.2.21

Solderability

The terminations meet the requirements

of IEC 115-1, clause 4.17.3.2

WH200 & 300

Material

M6 threaded steel terminal

Strength

Termination robustness 50N

Solderability

Non-solderable