Rev Date: 08/22/2018 1 www.seielect.com
This speci fication ma y be chang ed at a n y time witho ut pri or noti c e marketing@seielect.com
Please confirm technical specifications before you order and/or use.
SWT/EWT Series
Non-Flammable Edgewound Tubular Wirewound Resistor
Stackpole Electronics, I nc.
Resistive Product Solutions
0
300
350
350ºC
Ambient Temperature (ºC)
-60
0
50
100
150
200
250
Percent Rated Power (%)
100
-55ºC
25ºC
80
60
40
20
Features:
Power Derating Curve:
• High current capability
• RoHS compliant, lead-free and haloge n-free
• Non-inductive style only available with silicone coating
(NSWT)
• Suitable for soldering or thru bolt connections
• Wirewound ribbon on ceramic substrate
• SWT – Silicone coating provides temperature handling up
to 350ºC
• SWTA – Adjustable version
• EWT – Vitreous enamel coating provides temperature
handling up to 500ºC
Electrical Specifica tions
Dielectric
Type/Code Strength
VAC
SWT25 / EWT25 25W 2,500 0.1 -30K 0.1 -100 1-10K
SWT50 / EWT50 50W 2,500 0.1 -50K 0.1 -275 1-20K
SWT100 / EWT100 100W 2,500 0.1 -100K 0.12 -680 1-50K
SWT150 / EWT150 150W 2,500 0.1 -150K 0.22 -1.5K 1-80K
SWT175 / EWT175 175W 2,500 0.15 -100K 0.24 -1.3K 1-100K
SWT200 / EWT200 200W 2,500 0.1 -200K 0.25 -1.35K 1-120K
SWT225 / EWT225 225W 2,500 0.2 -130K 0.3 -1.7K 1-130K
SWT250 / EWT250 250W 2,500 0.5 -125K 0.33 -1.8K 1-200K
SWT300 / EWT300 300W 2,500 0.5 -150K 0.42 -2.25K 1-240K
Power Rating (Watts)
@ 25ºC
SWT
NSWT
EWT
Ohmic Range (Ω) and Tolerance
5%, 10%
Rev Date: 08/22/2018 2 www.seielect.com
This speci fication ma y be chang ed at a n y time witho ut pri or noti c e marketing@seielect.com
Please confirm technical specifications before you order and/or use.
SWT/EWT Series
Non-Flammable Edgewound Tubular Wirewound Resistor
Stackpole Electronics, I nc.
Resistive Product Solutions
Hardware:
• Sturdy plated steel brackets, thru-bolts, centering washers, and insulating washers
• Brackets provide elongated mounting holes for ease of mo unt i ng
Mounting Brackets Mechanical Specifications
Mechanic al Spec ifications
1.000 0.750 0.500 0.219 0.438 inches
25.40 19.05 12.70 5.56 11.13 mm
1.000 0.750 0.500 0.219 0.438 inches
25.40 19.05 12.70 5.56 11.13 mm
B
50W
E
Unit
C
D
25W
Resistor Power Rating
A
0.563 ±0.039 0.313 ±0.039 2.008 ±0.079 0.472 ±0.039 0.177 0.079 inches
14.30 ±1.00 7.94 ±1.00 51.00 ±2.00 12.00 ±1.00 4.50 2.00 mm
0.563 ±0.039 0.313 ±0.039 4.016 ±0.079 0.748 ±0.039 0.315 0.197 inches
14.30 ±1.00 7.94 ±1.00 102.00 ±2.00 19.00 ±1.00 8.00 5.00 mm
0.752 ±0.039 0.500 ±0.039 6.496 ±0.079 0.669 ±0.039 0.315 0.197 inches
19.10 ±1.00 12.70 ±1.00 165.00 ±2.00 17.00 ±1.00 8.00 5.00 mm
1.102 ±0.039 0.752 ±0.039 8.110 ±0.079 0.669 ±0.039 0.315 0.197 inches
28.00 ±1.00 19.10 ±1.00 206.00 ±2.00 17.00 ±1.00 8.00 5.00 mm
1.126 ±0.039 0.752 ±0.039 8.504 ±0.079 0.669 ±0.039 0.236 0.079 inches
28.60 ±1.00 19.10 ±1.00 216.00 ±2.00 17.00 ±1.00 6.00 2.00 mm
1.378 ±0.039 0.752 ±0.039 8.740 ±0.079 0.669 ±0.039 0.394 0.197 inches
35.00 ±1.00 19.10 ±1.00 222.00 ±2.00 17.00 ±1.00 10.00 5.00 mm
1.126 ±0.039 0.752 ±0.039 10.512 ±0.079 0.709 ±0.039 0.354 0.197 inches
28.60 ±1.00 19.10 ±1.00 267.00 ±2.00 18.00 ±1.00 9.00 5.00 mm
1.575 ±0.039 0.984 ±0.039 8.268 ±0.079 0.787 ±0.039 0.472 0.197 inches
40.00 ±1.00 25.00 ±1.00 210.00 ±2.00 20.00 ±1.00 12.00 5.00 mm
1.575 ±0.039 0.984 ±0.039 10.236 ±0.079 0.787 ±0.039 0.472 0.197 inches
40.00 ±1.00 25.00 ±1.00 260.00 ±2.00 20.00 ±1.00 12.00 5.00 mm
(1) NSWT series will have the same Mechanical Specifications as SWT series
SWT175 / EWT175
SWT200 / EWT200
SWT225 / EWT225
SWT250 / EWT250
SWT300 / EWT300
SWT100 / EWT100
SWT150 / EWT150
OD
ID
F
Unit
SWT25 / EWT25
SWT50 / EWT50
Type/Code(1)
E
G
L
Rev Date: 08/22/2018 3 www.seielect.com
This speci fication ma y be chang ed at a n y time witho ut pri or noti c e marketing@seielect.com
Please confirm technical specifications before you order and/or use.
SWT/EWT Series
Non-Flammable Edgewound Tubular Wirewound Resistor
Stackpole Electronics, I nc.
Resistive Product Solutions
Metal Centeri ng Washer Mica Insulating Was her
Bolt and Washers Mechanical Specifications
Mounting Brackets Mechanical Specifications (cont.)
1.000 0.750 0.500 0.219 0.438 inches
25.40 19.05 12.70 5.56 11.13 mm
1.500 0.875 1.250 0.281 0.563 inches
38.10 22.23 31.75 7.14 14.30 mm
1.500 0.875 1.250 0.281 0.563 inches
38.10 22.23 31.75 7.14 14.30 mm
1.500 0.875 1.250 0.281 0.563 inches
38.10 22.23 31.75 7.14 14.30 mm
1.500 0.875 1.250 0.281 0.563 inches
38.10 22.23 31.75 7.14 14.30 mm
1.500 0.875 1.250 0.281 0.563 inches
38.10 22.23 31.75 7.14 14.30 mm
1.500 0.875 1.250 0.281 0.563 inches
38.10 22.23 31.75 7.14 14.30 mm
300W
100W
150W
175W
200W
225W
250W
E
Unit
Resistor Power Rating
A
B
C
D
0.563 2.008 2.500 0.560 0.190 0.750 0.313 inches
14.30 51.00 63.50 14.22 4.83 19.05 7.95 mm
0.563 4.016 4.750 0.560 0.190 0.750 0.313 inches
14.30 102.00 120.65 14.22 4.83 19.05 7.95 mm
0.752 6.496 7.000 0.750 0.190 1.000 0.500 inches
19.10 165.00 177.80 19.05 4.83 25.40 12.70 mm
1.102 8.110 7.750 1.125 0.250 1.250 0.625 inches
28.00 206.00 196.85 28.58 6.35 31.75 15.88 mm
1.126 8.504 9.125 1.125 0.250 1.500 0.750 inches
28.60 216.00 231.78 28.58 6.35 38.10 19.05 mm
1.378 8.740 9.250 1.400 0.250 1.500 0.750 inches
35.00 222.00 234.95 35.56 6.35 38.10 19.05 mm
1.126 10.512 11.250 1.125 0.250 1.500 0.750 inches
28.60 267.00 285.75 28.58 6.35 38.10 19.05 mm
1.575 8.740 9.250 1.570 0.500 2.000 1.000 inches
40.00 222.00 234.95 39.88 12.70 50.80 25.40 mm
1.575 10.709 11.125 1.570 0.500 2.000 1.000 inches
40.00 272.00 282.58 39.88 12.70 50.80 25.40 mm
Resistor Power Rating
OD
Core
Length
Bolt
Length
Unit
C
D
A
B
Bolt No.
25W
50W
300W
175W
200W
10
10
10
0.25"
0.25"
225W
250W
100W
150W
0.5"
0.5"
0.25"
0.25"
Rev Date: 08/22/2018 4 www.seielect.com
This speci fication ma y be chang ed at a n y time witho ut pri or noti c e marketing@seielect.com
Please confirm technical specifications before you order and/or use.
SWT/EWT Series
Non-Flammable Edgewound Tubular Wirewound Resistor
Stackpole Electronics, I nc.
Resistive Product Solutions
RoHS Com plianc e
Stackpole Electronics has joined the worldwide effort to reduce the amount of lead in electronic components and to meet the various
regulatory requirements now prevalent, such as the European Union’s directive regarding “Restrictions on Hazardous Substances”
(RoHS 3). As part of this ongoing program, we periodically update this document with the status regarding the availability of our
compliant components. All our standard part numbers are compliant to EU Directive 2011/65/EU of the European Parliament as
amended by Directive (EU) 2015/863/EU as regards the list of restricted substances.
“Conflict Metals” Commitment
We at Stackpole Electronics, Inc. are joined with our industry in opposing the use of metals mined in the “conflict region” of the
eastern Democratic Republic of the Congo (DRC) in our products. Recognizing that the supply chain for metals used in the
electronics industry is very complex, we work closely with our own suppliers to verify to the extent possible that the materials and
products we supply do not contain metals sourced from this conflict region. As such, we are in compliance with the requirements of
Dodd-Frank Act regarding Conflict Minerals.
Spring Clip Mechanical Specifications
RoHS Compliance Status
0.625 0.250 0.469 0.313 inches
15.88 6.35 11.91 7.95 mm
0.625 0.250 0.469 0.313 inches
15.88 6.35 11.91 7.95 mm
25W
50W
D
Unit
Resistor Power Rating
A
B
C
SWT
Non-Flammable Edgewound Tubular
Wirew ound Silicone Coating Resistor
Special YES 100% M at te Sn Always Always
EWT
Non-Flammable Edgewound
Tubular Wirew ound Vitr eous
Enamel Coating Resist or
Special YES 100% M at te Sn Always Always
Standar d
Product
Series
Description
Package /
Termination
Type
Standard
Series
RoHS
Compliant
Lead-Fr ee Ter mination
Composition
Lead-Fr ee
Mfg. Effective Date
(St d Product Series)
Lead-Fr ee
Eff ective Date
Code
(YY/WW)
Rev Date: 08/22/2018 5 www.seielect.com
This speci fication ma y be chang ed at a n y time witho ut pri or noti c e marketing@seielect.com
Please confirm technical specifications before you order and/or use.
SWT/EWT Series
Non-Flammable Edgewound Tubular Wirewound Resistor
Stackpole Electronics, I nc.
Resistive Product Solutions
Complianc e to “REACH”
We certify that all passive components supplied by Stackpole Electronics, Inc. are SVHC (Substances of Very High Concern) free
and compliant with the requirements of EU Directive 1907/2006/EC, “The Registration, Evaluation, Authorization and Restriction of
Chemicals”, otherwise referred to as REACH. Contact us for complete list of REACH Substance Candidate List.
Environmental Policy
It is the policy of Stackpole Electronics, Inc. (SEI) to protect the environment in all localities in which we operate. We continually
strive to improve our effect on the environment. We observe all applicable laws and regulations regarding the protection of our
environment and all requests related to the environment to which we have agreed. We are committed to the prevention of all forms
of pollution.
How to Order
1 2 345678 9 10 11 12
E W T M 5 0 J B200 R
Code Code Code Quantity
-25
Each
M50
EWT S100
L150
A175
200
225
250
300
Description
Description
Type
Power
Power
Tol
All Sizes
K
10%
Code
Product Series
Tolerance
Resistance Value
Packaging
0.1 ohm = R100
1 ohm = 1R00
10 Kohm = 10K0
Four character s
w ith t he mult ip lie r
used as t he
decimal holder.
Size
NSWT
No n-induc ti ve
Silico ne Coa ting
200W
225W
175W
150W
Adjustable
Welded Str aight Leads
250W
300W
Vitreous Enamel
25W
B
Bulk
Std Tab Connection
Mount ing Hardw ar e
J
5%
50W
Spring Clips
Description
SWT
Silico ne Coa ting
(std)
Code
100W
