General Note
IRC reserves the right to make changes in product specification without notice or liability.
All information is subject to IRC’s own data and is considered accurate at time of going to print. A subsidiary of
TT electronics plc
• 4222 South Staples Street • Corpus Christi Texas 78411 USA
Wire and Film Technologies Division
Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com
Inorganic
fireproof
encapsulant
Steatite
ceramic case
Alloy resistance wire on
fiberglass substrate
Tinned steel
PW Radial Series
• 0.10Ω to 2.0KΩ
• 20 watts to 50 watts
• ±10% or ±5% tolerance
• RoHS compliant construction available
• Custom parts available - consult factory
General Purpose
Radial Terminal
Power Wirewound Resistor
IRC
Type
Power Rating @ 25°C
(watts)
Resistance
Range (ohms)
PW-20E 20 0.1 to 2.0K
PW-30 30 0.5 to 1.2K
PW-40 40 0.65 to 1.5K
PW-50E 50 0.08 to 1.8K
- Flameproof inorganic construction
- EIA RS-344, insulated fixed wirewound resistors
- 1000 hour load life at 25°C: 5% max.
- Moisture no load 240 hours: 2% max.
- Temperature cycling (5 cyc.): 5% max.
Electrical Data
Power Derating Curve
100
80
60
40
0 50 100 150 200 250
Ambient Temperature (°C)
20
0
PW - 20E, PW - 30, PW - 40
PW - 50E without Bracket
Percent of Rated Load
Temperature Rise Chart
300
200
100
00 25 50 75 100 125
Percent of Rated Load
Temperature Rise (°C)
PW - 50E
PW - 20E
PW - 40
PW - 30
With Bracket:
PW-30 Increased to 40 watts
PW-40 Increased to 50 watts
PW-50 Increased to 60 watts
PW Radial Series Issue December 2008 Sheet 1 of 2
• 4222 South Staples Street • Corpus Christi Texas 78411 USA
Wire and Film Technologies Division
Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com
Physical Data
Dimensions (Inches (mm))
IRC Type A B
PW-20E 1.875 ±0.030 2.5 ±0.060
PW-30 2.00 ±0.030 2.55 ±0.060
PW-40 2.45 ±0.030 3.00 ±0.060
PW-50E 3.075 ±0.030 3.625 ±0.060
PW-20E Wirewound PW-30, 40 and 50E Wirewound
PW-20E Alternate
Terminal
Configuration
-0.020" Tin coated Steel
General Purpose
Radial Terminal
Power Wirewound Resistor
Sample Part No.
IRC Type
PW20E, PW30, PW40, PW50E
Power
18 = 18 watts
Resistance Value
(standard EIA values)
Tolerance
±10% or ±5% standard
RoHS Indicator
LF indicates RoHS compliance
Ordering Data
PW 18 1202 K LF
0.032±0.0025
B
0.5±0.030
0.5±0.030
0.157±0.020
A
5/32 Dia. Thru (2)
0.250 (Typ.)
0.75±0.030
0.875
7/32 Dia.
0.25
0.75
0.375
0.032±0.0025
A
0.282±0.020
5/32 Dia. Thru (2)
0.75±0.030
Printed Circuit Terminal
0.069±0.005
0.205 or
0.187±0.005
0.25±0.031
0.135±0.015
0.200 (Typ.)
0.125±0.015
PW Radial Series Issue December 2008 Sheet 2 of 2
