Aluminium Housed
Aluminium Housed
Wirewound Resistors
WH Series
Wirewound Resistors
Terminations
WH5-100
Material
Strength
Pb-free solder dipped, copper clad steel
The terminations meet the requirements
of IEC 68.2.21
The terminations meet the requirements
of IEC 115-1, clause 4.17.3.2
WH25T & 50T
6.35mm (¼“) spade terminal
WH200 & 300
Material
M6 threaded steel terminal with a
set of four nuts and washers
Strength
Termination robustness 50N max
Tightening torque 5Nm max
Solderability
Performance Data
Load at commercial rating: 1000hrs at 25°C
Load at CECC rating: 1000hrs at 25°C
Dry heat: 1000hrs at 200°C
Derating from 25°C
Short-term overload
Climatic sequence
Climatic category
Long-term damp heat
Temperature rapid change
Resistance to solder heat
Vibration and bump
Noise (in decade of frequency)
Insulation resistance
Pulse and overload performance
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
µV/V
ohms
Note: A 0.05 ohm addition is to be added to the performance of all resistors < 10 ohms.
WH5, 10, 25 & 50
WH100, 200 & 300
CECC 40203-006
Actual
Maximum
Requirements
Maximum
Typical
1
1
0.4
2
1
1
0.4
N/A
1
1
0.4
2
Zero at 200°C, see derating graph
1
1
0.2
1
1
0.4
55/200/56
1
0.5
0.2
0.25
0.25
0.1
0.25
0.25
0.25
0.05
WH100: 0.5
0.25
0.25
0.025
Not specified
0
0
0
1G min
10G min
Not specified
See graphs
10000
1000
Pulse and Overload Performance
For short durations of
≤0.1s
the energy graph should
be used. For longer durations the overload graph
applies.
10
Energy (joules)
100
10
1
Multiple of Rated Power
WH25-300
WH300
WH200
WH100
WH50
WH25
WH10
WH5
WH5&10
WH5-50
WH100-300
1
0.1
1
10
Overload Duration (s)
100
1000
0.1
0.01
0.1
1
10
100
1000
Value (ohms)
10000 100000
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 thinly 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.
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
Welwyn Electronics Park, Bedlington, Northumberland, NE22 7AA, England. Tel: 01670
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
Welwyn
Components Limited
822181 Fax: 01670 829465 Web: www.welwyn-tt.com
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
© TT electronics plc
07. 12
WELWYN [ WELWYN COMPONENTS LIMITED ]
