ETC WA84

General Purpose Cement
Coated Wirewound
Resistors
WA80 SERIES
● Flameproof cement coating
● All welded construction
● Resistance values down to 0.01 ohms
Electrical Data
WA82
WA83
1
2.0
.86
1.6
0.068 to 430 0.05 to 900
50
50
250
250
<1Ω:350
Power rating at 25°c
watts
Power rating at 70°c
watts
Resistance range
ohms
Limiting element voltage volts
Isolation voltage
volts
TCR
ppm/°C
Resistance tolerance
%
Values
Thermal impedance
°C/watt
Ambient temperature range °C
140
WA835
2.5
2.0
0.05 to 900
75
250
WA84
3.0
2.5
0.01 to 2K2
100
350
WA85
5
4.3
.05 to 4K5
150
500
>1Ω:200
WA87
7
6
0.15 to 10K
150
700
54
35
5, 10
E24 preferred
82
90
- 55 to 155
110
Physical Data
Dimensions (mm) and Weight (g)
Type
WA82
WA83
WA835
WA84
WA85
WA87
L max.
6.2
9.0
12.5
14.5
16.5
25.0
D max.
2.8
3.6
4.5
5.2
7.0
8.8
f min.
21.20
19.80
17.80
24.55
23.55
28.30
d nom.
0.6
0.8
0.8
0.8
0.8
0.8
PCB
mounting
centres
10.20
12.70
18.40
20.30
22.86
31.40
CONSTRUCTION
A high quality ceramic substrate is assembled with
interference fit end caps to which are welded the termination
wires. The resistive element is wound on the substrate and
welded to the caps. Cement protection is applied to the
resistor body before marking with indelible ink.
TERMINATIONS
Material
Solder-coated copper wire on 82, 83, 835 and
84, copper weld on 85 and 87.
Strength
The terminations meet requirements of
IEC 68.2.21.
Solderability The terminations meet the requirements of
IEC 115-1, Clause 4.17.3.2.
Min
bend
radius
0.6
1.2
1.2
1.2
1.2
1.2
Wt
nom.
0.22
0.50
0.50
1.10
1.75
4.40
d dia
D
L
f
MARKING
WA85 and 87 resistors are legend marked with type
reference, resistance value and tolerance. In conformance
with IEC 62.
WA82, 83, 835 and 84 resistors RIO and above are colour
coded with 4 bands in conformance with IEC 62. Values
below RIO are 3 band marked, two digits and tolerance,
there is no multiplier band.
SOLVENT RESISTANCE
The body protection and marking are resistant to all normal
industrial cleaning fluids suitable for printed circuits.
FLAMMABILITY
The resistor coating will not burn under any condition of
applied temperature or component overload.
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 data and is considered accurate at time of going to print.
© Welwyn Components Limited
Bedlington, Northumberland NE22 7AA, England Tel: 01670 822181 Fax: 01670 829465 Web: http://www.Welwyn-TT.co.uk
Issue A 07/99
General Purpose Cement Coated
Wirewound Resistors
WA80 SERIES
Performance Data
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
TYPICAL
5.0 + .001
3.0
5.0 + .001
3.0
See derating curve
5.0 + .001
1.0
5.0 + .001
2.0
55/200/56
5.0 + .001
1.0
5.0 + .001
1.0
5.0 + .001
1.0
Data Available by Request
WA80 Series Derating Curve
% of Rated Power at 70
MAXIMUM
Load at rated power: 1000 hrs
at 25 or 70°c
Dry heat: 1000 hrs at 200°c
Derating from rated power at 25°c
Short term overload
Climatic
Climatic category
Long term damp Heat: 56 days
T.R.C. & Vibration
Robustness & Solder Heat
Pulse Handling
130
120
110
100
90
80
70
60
50
40
30
20
10
0
20
40
60
80 100 120 140 160 180 200 220 240 260 280
Temp
APPLICATION NOTES
Care must be taken when determining clearance
between the resistor body and the P.C.B. or other
components. Resistance is measured 6mm from
body.
Figure 2
PACKAGING
All resistors are supplied tape packed ready for
loading onto automatic sequencing and insertion
machines. The critical dimensions are shown in
figure 2.
c
Component wires will not protrude beyond the
outside edge of the tapes.
f1
All taped resistors will be supplied either on reels or
in ammopacks, depending upon quantities orderded.
WA series resistors can be supplied preformed.
Contact factory for details.
6
f2
b
6
Body Location f1 – f2 ≤ 1.4 mm
Type
b
c
WA82 WA83 WA835 WA84 WA85 WA87
52
52
52
67
63
85
5
5
5
10
10
10
STANDARD QUANTITIES PER PACKAGE
Type
Reel
Large Ammopack
WA82
5000
5000
WA83
2500
2500
WA835
2500
1500
WA84
1000
1000
WA85
750
700
WA87
700
n/a
© Welwyn Components Limited
Bedlington, Northumberland NE22 7AA, England Tel: 01670 822181 Fax: 01670 829465 Web: http://www.Welwyn-TT.co.uk
Issue A 07/99