document number: 30203

For technical questions, contact: ww2bresistors@vishay.com

www.vishay.com

Revision: 22-Oct-08

159

ESS, ESN, EGS, EGN

Wirewound Resistors, Military/Established Reliability

MIL-PRF-39007 Qualified, Type RWR, R Level

Vishay Dale

DIMENSIONS in inches [millimeters]

Note

to a shorter length than shown

MATERIAL SPECIFICATIONS

Element: Copper-nickel alloy or nickel-chrome alloy,

depending on resistance value

Core: Ceramic, beryllium oxide, steatite or alumina,

depending on power requirement

Coating: Special high temperature silicone

Terminal and Winding: The terminal and the winding are

identified by a letter symbol in the military type designation.

Military symbol:

S = Solderable, inductively wound

W = Weldable, inductively wound

N = Solderable, non-inductively wound

Z = Weldable, non-inductively wound

Weldable - bare nickel per MIL-STD-1276, Type N-1

End Caps: Stainless steel

Part Marking: Source code, JAN, military PIN, date/lot code

APPLICABLE MIL-SPECIFICATION

MIL-PRF-39007: This is the military specification covering

axial lead established reliability power wirewound resistors.

Vishay Dale ESS, ESW, EGS, EGW, ESN and EGN

resistors meet or exceed the electrical, environmental and

dimensional requirements of this specification.

Note

• For resistance values above 100

Ω, test limit is ± 1.0 %

B

min.

A

C

MIL-PRF-39007

DIMENSIONS in inches [millimeters]

MODEL

A

B

C

RWR81

0.250 ± 0.031

[6.35 ± 0.787]

0.085 ± 0.020

[2.16 ± 0.508]

0.020 ± 0.0015

[0.508 ± 0.038]

RWR82

0.312 ± 0.016

[7.92 ± 0.406]

0.078 + 0.016 - 0.031

[1.98 + 0.406 - 0.787]

0.020 ± 0.0015

[0.508 ± 0.038]

RWR80

0.406 ± 0.031

[10.31 ± 0.787]

0.094 ± 0.031

[2.39 ± 0.787]

0.020 ± 0.0015

[0.508 ± 0.038]

RWR71

0.812 ± 0.062

[20.62 ± 1.58]

0.187 ± 0.031

[4.75 ± 0.787]

0.032 ± 0.002

[0.813 ± 0.051]

RWR89

0.560 ± 0.062

[14.22 ± 1.58]

0.187 ± 0.031

[4.75 ± 0.787]

0.032 ± 0.002

[0.813 ± 0.051]

RWR74

0.875 ± 0.062

[22.23 ± 1.58]

0.312 ± 0.031

[7.92 ± 0.787]

0.040 ± 0.002

[1.02 ± 0.051]

RWR84

0.875 ± 0.062

[22.23 ± 1.58]

0.312 ± 0.031

[7.92 ± 0.787]

0.040 ± 0.002

[1.02 ± 0.051]

RWR78

1.780 ± 0.062

[45.21 ± 1.58]

0.312 ± 0.031

[7.92 ± 0.787]

0.040 ± 0.002

[1.02 ± 0.051]

Derating

AMBIENT TEMPERATURE IN °C

25

0

20

40

60

80

100

120

- 65 - 50

0

50

150

250

TECHNICAL SPECIFICATIONS

PARAMETER

UNIT

RWR RESISTOR CHARACTERISTICS

Temperature Coefficient

ppm/°C ± 650 for 0.1

Ω to 0.499 Ω, ± 400 for 0.505 Ω to 1 Ω, ± 50 for 1.1 Ω to 10 Ω, ± 20 for 10 Ω and above

Dielectric Withstanding Voltage

500 minimum for 2 W and smaller, 1000 minimum for 3 W and larger

Short Time Overload

-

5 x rated power for 5 s for 3 W size and smaller,

10 x rated power for 5 s for 5 W size and greater

Maximum Working Voltage

V

(

Insulation Resistance

.

1000 M

Ω minimum dry, 100 MΩ minimum after moisture test

Terminal Strength

lb

5 minimum for 2 W and smaller, 10 minimum for 3 W and larger

Solderability

-

Meets requirements of ANSI J-STD-002

Operating Temperature Range

°C

- 65 to + 250

PERFORMANCE

TEST

CONDITIONS OF TEST

TEST LIMITS

Thermal Shock

MIL-STD-2.2, Method 303

± (0.2 % + 0.005

Ω) ΔR

Short Time Overload

5 x rated power (RWR71, 80, 81, 89, 82), 10 x rated power (RWR74, 78, 84) for 5 s ± (0.2 % + 0.005

Ω) ΔR

Dielectric Withstanding

Voltage

1 min duration

± (0.1 % + 0.005

Ω) ΔR

Low Temperature Storage

- 65 °C for 24 h

± (0.1 % + 0.005

Ω) ΔR

High Temperature Exposure

250 °C for 2000 h

± (1.0 % + 0.005

Ω) ΔR

Moisture Resistance

MIL-STD-202, Method 106

± (0.2 % + 0.005

Ω) ΔR

Shock, Specified Pulse

MIL-STD-202, Method 205, condition C

± (0.1 % + 0.005

Ω) ΔR

Vibration, High Frequency

MIL-STD-202, Method 204, condition D

± (0.1 % + 0.005

Ω) ΔR

Load Life

2000 h at rated power, + 25 °C, 1.5 h “ON”, 0.5 h “OFF”

± (0.5 % + 0.005

Ω) ΔR

Extended Life

10 000 h at rated power, + 25 °C, 1.5 h “ON”, 0.5 h “OFF”

± (1.0 % + 0.005

Ω) ΔR

Terminal Strength

MIL-STD-202, Method 211, condition A and C

5 pound (RWR80, 81, 82), 10 pound (RWR71, 74, 78, 84, 89)

± (0.1 % + 0.005

Ω) ΔR