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
SPH/SPF SERIES
GENERAL-PURPOSE FAILSAFE
MOLDED WIREWOUND RESISTOR
• SPF is Fusible
• 2 watt rated with 1 watt dimensions
• ±5%, ±10% tolerance
• 0.1 ohm to 2400 ohms
• TCR's as low as ±150 ppm/°C std (custom TC's available)
• Drop-in replacement for BWH/BWF
• Weldable and solderable leads
• Lead Free, ROHS Compliant Construction Available
WIREWOUND AND FILM TECHNOLOGIES DIVISION
736 Greenway Road • Boone, North Carolina 28607-1860 • Tel: 828-264-8861 • Fax: 828-264-8866 • www.irctt.com
2
3
4
1
See notes below
SPH
CRU 2
RC32/RC42
0.1Ω to 2400Ω
±5%, ±10%
2 watt @ 70°C
1 watt @ 115°C
Derating to 0 @ 160°C
√PR
10,000 Meg
100 Meg
1000 V
625V
145°C @ 2 watts
5%
Negligible
IRC Type
EIA RS-344 Style
MIL-R-11 Style
Resistance - Std.
Tolerance - Std.
Power Rating
Max. Continuous Working
Voltage
Min. Insulation Dry
Resistance Wet
Min. Dielectric ATM
Withstanding Volts
(RMS) Reduced Pressure
Hotspot Temperature Rise
Typical Load Life
Current Noise
SPECIFICATIONS: 1. Resistive Element
All resistor types have resistance alloy
winding on a braided fiberglass substrate.
Intermediate silicone coatings are used to
enhance processibility and to provide pro-
tection to the resistive element.
2. Termination
The SPH and SPF resistors are terminated
using an alloy coated copper flashed steel
lead welded to a cap of the same material.
This termination assembly is mechanically
crimped, utilizing an improved crimp design,
to the resistive element.
3. Encapsulation
The SPH and SPF are encapsulated utiliz-
ing a compression molded phenolic plastic
material. The SPF has a flame-resistance
coating applied over the resistive element
to provide flammability protection when
destructive overloads may occur.
4. Marking
All products are marked utilizing heat and
solvent resistant color code bands consis-
tent with EIA/MIL requirements. The first
band is double width to designate wire-
wound construction. A fifth band, blue in
color, is used for flameproof identification.
SPF
CRU 2
RC32/RC42
0.1Ω to 1000Ω
±5%, ±10%
2 watt @ 70°C
1 watt @ 115°C
Derating to 0 @ 160°C
√PR
10,000 Meg
100 Meg
1000 V
625V
145°C @ 2 watts
5%
Negligible
DIMENSIONS (Inches and (mm)):
B
0.225±0.008
(5.72±0.20)
0.225±0.008
(5.72±0.20)
A
0.562±0.010
(14.3±0.25)
0.562±0.010
(14.3±0.25)
IRC TYPE
SPH
SPF
C
0.032±0.002
(0.813±0.05)
0.032±0.002
(0.813±0.05)
D
1.50±0.126
(38.1±3.2)
1.50±0.126
(38.1±3.2)
SPF
0.10Ω ±1700
0.11Ω - 0.16Ω ±1000
0.18Ω - 0.68Ω ±800
0.75Ω - 1000Ω ±400
1000V
5%
5%
5%
5%
5%
5%
5%
No Failures
SPH
0.1Ω - 0.16Ω ±1000
0.18Ω - 0.68Ω ±800
0.75Ω - 2400Ω ±400
1000V
5%
5%
5%
5%
5%
5%
5%
No Failures
Test
Temperature Coefficient (ppm)*
Dielectric Withstanding Voltage (RMS)
Momentary Overload
Low Temperature Operation
Temperature Cycle
Humidity
Load Life
Terminal Strength
Resistance to Solder Heat
Solderability
SPH POWER DERATING: SPF TYPICAL FUSING:SPF POWER DERATING:
SPH AND SPF
TEMPERATURE RISE:
HOW TO ORDER:
Sample Part No.:
SPH 150Ω 5% LF
IRC Type
Resistance Range
Tolerance
Lead Free Construction
Power (watts)
Power (watts)
Ambient Temperature (°C) Ambient Temperature (°C) Time (seconds)
Power (watts)
SPH/SPF CHARACTERISTICS (TYPICAL PERFORMANCE):
*All ppm levels listed are maximum.
Temperature Rise (°C)
Power Input (watts)
WIREWOUND AND FILM TECHNOLOGIES DIVISION
736 Greenway Road • Boone, North Carolina 28607-1860 • Tel: 828-264-8861 • Fax: 828-264-8866 • www.irctt.com
