Resistors
UL Recognised
Wirewound Resistors
ULW Series
UL1412 recognised fusible resistor *
Failsafe mains fusing at 120 / 240Vrms
Inrush and surge withstanding
UL94-V0 flameproof coating
Surface mount ZI-form option
* UL file number E234469.
All Pb-free parts comply with EU Directive 2011/65/EU (RoHS2)
Electrical Data
ULW2 / ULWP2R
Power rating at 25°C
5 second overload rating at 25°C
Inrush / surge performance
Resistance range
TCR
Isolation voltage
Resistance tolerance
UL recognised standard values
Thermal impedance
Ambient temperature range
ohms
ppm/°C
volts
%
ohms
°C/watt
°C
110
82
-55 to +155
250
350
5
Any value in the range 1R0 to 100R is recognised. E24 preferred
62
54
watts
watts
2
10
ULW3
3
15
1R0 to 100R
±200
500
ULW4
4
20
ULW5
5
25
See Pulse Performance graphs
Note - no limiting element voltage applies; maximum continuous voltage is √(P.R)
Physical Data
Dimensions (mm) and weight (g)
Type
ULW2
ULW3
ULW4
ULW5
L Max
9.0
14.5
13
16.5
D Max
3.8
5.8
5.6
7.2
f min
19.8
24.6
22.8
23.6
0.8
d nom
PCB
mount
centres
12.7
20.3
18.9
22.9
1.2
Min
bend
radius
Wt.
Nom
0.5
1.1
1.0
1.8
d
D
L
f
Construction
A high purity ceramic rod is assembled with interference fit end caps to which are welded the terminations. The surge withstanding resistive element is
wound on the rod and welded to the caps. Flameproof fusible cement coating is applied prior to marking with indelible ink. The components are then
leadformed if required and packed.
Marking
ULW2, ULWP2R & ULW3 resistors are marked with five colour bands. The first four indicate value and tolerance in conformance with IEC62. The fifth yellow
band denotes defined fusibility. ULW4 and ULW5 resistors are legend marked with type, value and tolerance.
General Note
TT Electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
BI Technologies IRC Welwyn
www.ttelectronics.com/resistors
© TT Electronics plc
09.17
UL Recognised
Wirewound Resistors
ULW Series
Terminations
Material:
Strength:
Solderability:
Hot tin dipped copper wire
The terminations meet the requirements of IEC 68.2.21
The terminations meet the requirements of IEC 115-1 Clause 4.17.3.2
Solvent Resistance
The body protection and marking are resistant to all normal industrial cleaning solvents suitable for printed circuits.
Flammability
The resistor coating will not burn or emit incandescent particles under any condition of applied temperature or power overload.
Performance Data
Maximum*
Load at rated power (1000 hours @ 25°C)
Short term overload (5 x Pr for 5 seconds)
Pulse (see Pulse Performance graphs)
Climatic
Long term damp heat (56 days)
Climatic category
Temperature rapid change
Dry heat (1000 hours @ 200°C)
Vibration
Robustness & solder heat
* Addition of 0.01Ω applies
ΔR%
ΔR%
ΔR%
ΔR%
5
5
5
5
ΔR%
ΔR%
ΔR%
ΔR%
ΔR%
5
5
5
5
5
55/200/56
1
3
1
1
Typical
3
1
2
2
1
Thermal Performance
Derating Curve
300
Body Temperature Rise
Proportion of Rated Power (%)
100
80
60
40
20
0
0
50
100
150
200
250
300
Am bient Tem perature (°C)
Temperature Rise (°C)
250
200
150
100
50
0
0
ULW2 / ULWP2R
ULW3
ULW4
ULW5
1
2
3
4
5
Power (W)
General Note
TT Electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
BI Technologies IRC Welwyn
www.ttelectronics.com/resistors
© TT Electronics plc
09.17
UL Recognised
Wirewound Resistors
ULW Series
Compact
Flameproof Power
Wirewound Resistors
WP-S Series
Application Notes
Application Notes
(Delete redundant subtitle)
Welwyn Components
1. If the resistors are to dissipate full rated power, it is recommended that the terminations should not be soldered closer than 4mm from the body.
Application Notes
2. Due to operating temperature limits imposed by some PCB materials, derating may be necessary. An estimate of the temperature rise to be expected can
Application Notes
be calculated using the thermal impedance figures given under Electrical Data.
1. If the resistors are to dissipate full rated power, it is recommended that the terminations should not be soldered closer than
4mm from the body.
1. If the resistors are to dissipate full rated power, it is recommended that the terminations should not be soldered closer than
3. For the purposes of UL approval, the following points should be observed:
4mm from the
2. Due to operating temperature limits imposed by some PCB materials, derating may be necessary. An estimate of the
body.
3.1 To protect against fire under all conditions of overload, a positive clearance of at least
13mm
temperature rise to
between the
at the
of the resistor
body
any combustible materials.
thermal impedance figures given under
should be provided
be expected
body
center of the
and
can be calculated using the
2. Due to
3.2 A positive
temperature limits imposed by some PCB
the resistor body or terminations
necessary. An estimate of the
operating
clearance of 13mm should be provided between
materials, derating may be
Electrical Data.
temperature
uninsulated
expected at the center of the body
dead metal parts.
and
rise to be
parts of opposite polarity or uninsulated
can be calculated using the thermal impedance figures given under
Electrical
3.3 Limited Short
purpose
testing
approval, the following points should be observed:
Data.
3. For the
Circuit
of UL
should be performed in the complete appliance.
3.1 To protect against fire under all conditions of overload, a positive clearance of at least 13mm should be provided
between the body of the resistor and
lancet pre-formed leads. In
4. ULW resistors can also be supplied with radial, goalpost or
goalpost or lancet pre-formed leads. In
ULW3, ULW4 and ULW5 are available in ZI-form
3. WP-S resistors can also be supplied with radial,
any combustible materials.
particular ULW2,
particular, WP2S, WP3S, WP4S and WP5S
SMD
available in ZI-form SMD format packed in blister tape - see http://www.ttelectronicsresistors.com/pdf/datasheet/ZI-form.pdf
blister tape – see http://www.ttelectronics.com/sites/default/files/resistors-datasheets/ZI-form.pdf
are
format packed in
3.2 A positive clearance of 13mm should be provided between the resistor body or terminations and uninsulated parts of
opposite polarity or uninsulated dead metal parts.
3.3 Limited Short Circuit testing should be performed in the complete appliance.
Radial
4. ULW resistors can also be supplied with radial, goalpost or lancet pre-formed leads. In particular ULW2, ULW3, ULW4 and
ULW5 are available in ZI-form SMD format packed in blister tape – see
(This diagram exists on WP-S,
http://www.ttelectronics.com/sites/default/files/resistors-datasheets/ZI-form.pdf
so just copy it)
Goalpost
Lancet
Z I-form
Also a 2W radial taped version* is available as shown below
Dimension
Packaging
ULWP2R Radial Taped Dimensions (mm)
Also a 2W radial taped version* is available as shown below.
Notation
Nominal
Tolerance
The standard packaging for WP-S is taped. The
Max
Component Body Diameter
D
Dimension
Notation
4.0
critical dimensions are shown in Figure 1. The component wires will not
Nominal
Tolerance
Component
10.0
Taped product is then packed into boxes or onto reels; see Ordering Procedure
Max
protrude
Lead Diameter
outside
Length
of the tapes.
Nom
beyond the
Body
edge
d
L
Terminal
0.8
Component Body Diameter
available by request.
±0.5
D
4.0 Max
Component
Alternative packaging is
P
12.7
for details.
Pitch
Pre-formed resistors are supplied loose packed in plastic bags or boxes.
Po
Component Pitch
P
P1
Pitch of
& Component
Holes
Po
Distance between Hole
P2
P1
Distance between Hole &
Lead Pitch
Component
b
Dimensions (mm)
c
F
P2
Width of Backing
Lead Pitch
Strip
W
F
WP1S
52
5
Position of Hole
Width of Backing Strip
W1
W
WP2S
of Hole
Position of Hole
52
5
Do
W1
Diameter
Diameter of Hole
Do
Height to Lead Form
WP25S
52
5
Ho
Ho
Height from Lead
Height to Lead Form
Form
Ho1
WP3S
67
Form
10
Ho1
Height from Lead
Height to Resistor
Ho2
Height to Resistor
Ho2
WP4S
63
10
W2
Width of Adhesive Tape
Width of Adhesive Tape
W2
Length of protrusion
l
WP5S
63
10
l
Length of protrusion
K1
K1
K2
K2
Form Dimensions
Form Dimensions
K3
K3
K4
K4
Pitch of Holes
Terminal Lead Diameter
d
Component Body Length
Radial Taped Dimensions (mm)
Max
L
10.0
ULWP2R
*Although body dimensions differ slightly, ULWP2R Performance and Electrical Data are identical to those of ULW2
*Although body dimensions differ slightly, ULWP2R Performance and Electrical Data are identical to those of ULW2
12.7
±0.2
5
±0.5
3.85
±0.3
10
±0.2
5.85
±0.5
Figure 1
3.85
±0.3
5.0
+0.75 -0.34
5.85
±0.5
18.0
±0.3
5.0
+0.75 -0.34
9.0
±0.25
18.0
±0.3
9.0
±0.25
4.0
±0.3
4.0
±0.3
16.0
±0.3
16.0
±0.3
21.7 Max
17.0 MAX
18.0 Max
18.0 MIN
15.0
±0.5
15.0
±0.5
<2.5
<2.5
6
2.0
±0.3
2.0
±0.3
3.0
±0.5
3.0
±0.5
1.5
±0.25
1.5
±0.25
1.0
±0.2
1.0
±0.2
0.8 Nom
C
f1
b
f2
6
Body location f1 - f2 < 1.4mm
General Note
TT Electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
BI Technologies IRC Welwyn
www.ttelectronics.com/resistors
© TT Electronics plc
09.17
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