Aluminium Housed
Wirewound Resistors
WH Series
Highpowerdissipaonupto300W
Allweldedconstrucon
Suitableforsevereenvironments
Designedforexcellentthermalconducvitytoheatsink
Spadeterminalopon
RoHScompliant
Aluminium Housed
Wirewound Resistors
WH Series
•High power dissipation up to 300W
•All welded construction
•Suitable for severe environments
•Designed for excellent thermal conductivity to heatsink
•Spade terminal option
•RoHS compliant
Electrical Data
WH5 WH10 WH25 WH50 Notes
Power rating at 25°Cwatts10 15 25 2 50 1, 2 On standard heatsink
Resistance range ohms 0R01 to 10K 0R01 to 20K 0R01 to 44K 0R015 to 120K
TCR (-55° to 200°C) ppm/°C <10R: ±75 ≥10R to <100R: ±50 ≥100R: ±25
Resistance tolerance % 1(F), 2(G), 5(J) and10(K)
Low value limits ohms 1R at 1% 0R5 at 2% 0R05 at 5% 0R01 at 10% WH50 0R015 at 10%
Isolation voltage volts 1500 1500 3000 3000 DC or AC peak
Note 1: For load at full rating mounton aluminium heatsink 30.5 cm x 30.5 cm x 1.5 mm Note 2: WH25T & WH50T are additionally rated at 15A
CECC 40203-006 Requirements * AA BA CA DA Notes
Power rating at 25°Cwatts10 15 25 40 On standard heatsink
Resistance range ohms 0R05 to 3K4 0R05 to 15K 0R05 to 33K 0R05 to 82K
TCR (-55° to 200°C) ppm/°C ≥5R to ≤10R: ± 100>10R: ±50
Resistance tolerance % 1(F), 2(G), and 5(J)
Low value limits ohms 1R at 1% 0R5 at 2% 0R05 at 5%
Isolation voltage volts 1000 1000 2000 2000 DC or AC peak
* This table indicates the CECC specification requirements which are met or exceeded by the corresponding WH series products.
Limiting element voltage volts 150 250 500 1250 DC or AC rms
Standard values E24 preferred range Other values to order
Thermal impedance °C/watt 16.0 10.0 6.0 3.5 On standard heatsink
Ambient temperature range °C -55 to 200
WH100 WH200 WH300 Notes
Power rating at 25°Cwatts100 200 300 On standard heatsink
Resistance range ohms 0R01 to 70K 0R01 to 50K 0R01 to 68K
TCR (-55° to 200°C) ppm/°C ≤1K0: ±100 >1K0: ±25
Resistance tolerance % Standard 5(J) and 10(K). also available : 1(F) and 2(G)
Low value limits ohms Typically ≥0R05: ±5% ≤0R047: ±10%
Isolation voltage volts 6360 7070 7070 DC or AC peak
Limiting element voltage volts 1900 1900 2500 DC or AC rms
Standard values E24 preferred range Other values to order
Thermal impedance °C/watt 1 0.7 0.6 On standard heatsink
Ambient temperature range °C -55 to 200
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
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Resistors
AllPb-freepartscomplywithEUDirecve2011/65/EU(RoHS2)
07.14
General Note
TT Electronics reserves the right to make changes in product specication without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
© TT Electronics plc
www.ttelectronicsresistors.com
Aluminium Housed
Wirewound Resistors
WH Series
Aluminium Housed
Wirewound Resistors
Physical Data
Dimensions(mm) & Weight (g)
WH5, 10, 25 & 50
A B C E F G H L M N Dt Wt.
Type Max ±0.3 ±0.3 Min Max Max Dia ±0.2 Max ±0.5 Max Min Nom
WH5 30 12.4 11.3 1.9 17 9 2.4 17.0 4.3 1.8 2.5 3.6
WH10 36.5 15.9 14.3 1.9 21 11 2.4 21.0 5.2 2.2 2.9 5.6
WH25 51 119.8 18.3 2.8 28 15 3.3 29.0 7.2 2.6 4.3 13
WH50 72.5 221.4 39.7 2.8 30 16 3.3 51.0 7.9 2.6 5.1 29
WH100, 200 & 300
A
Max
B
Max
C
Max
D
Max
E
Max
F
±0.3
G
±0.3
H
Max
J
Max
K
Max
L
Nom 3M
Max
Dt
Min
Wt.
Nom
WH100 47.5 88 24.1 27.3 65.2 35 37 11.8 15.4 3.7 4.4 - 7.0 115
WH200 72.5 145.7 41.8 45.5 89.7 70 57.2 20.5 10.4 5.5 5.1 103.4 15 475
WH300 72.5 184.4 41.8 45.5 127.7 104 59 20.5 12.4 5.5 6.6 141.4 15 700
Note 1: Amax for WH25T is 71.3 Note 2: Amax for WH50T is 95.5 Note 3: WH100: ±0.25, WH200 & 300: ±0.45
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
Construction
Cap and lead assemblies are fitted to a high purity
ceramic substrate. The resistive element is wound onto
the substrate and welded to the caps. The wound rod is
then moulded and fitted into aluminium housing to give
optimum stability and reliability.
Marking
The resistors are legend marked with type reference,
resistance value and tolerance which will withstand all
accepted industrial cleaning fluids. Values are marked
in accordance with IEC 62
End face tracking distance = Dt
WH100
WH200 &300
WH5
,10,25 &
50
Spade terminal on
WH25T & WH50T
Nominal dims in mm
Make Possible
07.14
General Note
TT Electronics reserves the right to make changes in product specication without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
© TT Electronics plc
www.ttelectronicsresistors.com
Aluminium Housed
Wirewound Resistors
Performance Data
WH5, 10, 25 & 50 WH100, 200 & 300
ActualCECC 40203-006
Requirements Maximum Typical Maximum
Load at commercial rating: 1000hrs at 25°CΔR% 1 1 0.4 2
Load at CECC rating: 1000hrs at 25°CΔR% 1 1 0.4 N/A
Dry heat: 1000hrs at 200°CΔR% 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 changeΔR% 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 ohmaddition is to be added to the performance of all resistors < 10 ohms.
Application Notes
After soldering, care should be taken toensure that there are no flux residueson 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.
Welwyn Components Limited
Welwyn Electronics Park, Bedlington, Northumberland, NE22 7AA, England. Tel: 01670 822181 Fax: 01670 829465 Web: www.welwyn-tt.com
1
10
0.1 110 100 1000
Overload Duration (s)
Multiple of Rated Power
WH5&10
WH100-300
WH25-300
WH5-50
0.1
1
10
100
1000
10000
0.01 0.1 110 100 1000 10000 100000
Value (ohms)
Energy (joules)
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
WH25T & 50T
6.3
5
mm
(
¼“)
spade terminal
WH200 &300
Material M6 threaded steel terminal with a
set of fournuts and washers
Strength Termination robustness 50N max
Tightening torque 5Nm max
Aluminium Housed
Wirewound Resistors
WH Series
Make Possible
07.14
General Note
TT Electronics reserves the right to make changes in product specication without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
© TT Electronics plc
www.ttelectronicsresistors.com
Aluminium Housed
Wirewound Resistors
The standard aluminium heatsinks are defined in the table below. If smaller heatsinks are used then derating should
be applied as indicated in the graph below. If no heatsink is employed, use the ratings for 1cm2.
Packaging
WH resistors are packed in plastic bags and boxed.
Ordering Procedure
Example: WH25 with spade terminals at 100 ohms with a 5% tolerance:
W H 2 5 T – 1 0 0 R J I
Type
Termination
Standard
T Spade terminal
Value (use IEC62 code)
Tolerance (use IEC62 code)
F 1% J 5%
G 2% K 10%
Packing
The following options apply to WH5, 10, 25 & 50 only:
For CECC released product state on order the CECC number and style. Example: WH25-3K3JI CECC40203-006 CA
For SnPb finish instead of Pb-free replace the packing suffix with PB. Example: WH25-3K3JPB
Type (CECC) Thickness (mm) Area (cm²)
WH5 (AA) 1 410
WH10 (BA) 1 410
WH25 (CA) 1 544
WH50 (DA) 1 544
WH50 @ 50W 1.5 930
WH100 3 1000
WH200 3 3800
WH300 3 5800
Reference heatsink dimension
s
1
10
100
1000
1 10 100 1000 10000
Heatsink Surface Area (cm
2
)
Ma ximum D issipa tion (W )
WH10/BA 70
°C
WH10/BA 25
°C
WH5/AA 70
°C
WH5/AA 25
°C
WH25/CA 70
°C
WH25/CA 25
°C
DA 70
°C
DA 25
°C
WH50 25
°C
WH100 70
°C
WH100 25
°C
WH200 70°C
WH200 25
°C
WH300 70
°C
WH300 25
°C
0
20
40
60
80
1 0 0
1 2 0
0 1 0 0 2 0 0
A m b ie n t T e m p e ra tu r e ( °C )
Proportion of Pr (%)
Derating for reduced heatsink dimensions
Derating for ambient temperature
I
WH5, 10
Bulk
250/box
Standard
WH25, 50 200/box
WH100 45/box
WH200, 300 10/box
The following options apply toWH5, 10, 25 & 50 only:
For CECC released product state on order the CECC number and style. Example: WH25-3K3JI CECC40203-006 CA
For SnPb nish instead of Pb-free replace the packing sufx with PB. Example: WH25-3K3JPB
Aluminium Housed
Wirewound Resistors
WH Series
Make Possible
07.14
General Note
TT Electronics reserves the right to make changes in product specication without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
© TT Electronics plc
www.ttelectronicsresistors.com
