Owner manual

Document Number: 50006 For technical questions, contact: [e-mail]
www.vishay.com
Revision: 09-Jun-08 2
RCH
Power Resistors, for Mounting onto a Heatsink
Thick Film Technology
Vishay Sfernice
MECHANICAL SPECIFICATIONS
Mechanical Protection Insulated case
Substrate Alumina
Resistive Element Cermet
Connections Tinned copper alloy
ENVIRONMENTAL SPECIFICATIONS
Temperature Range - 55 °C to + 125 °C
Climatic Category 55/125/56
ELECTRICAL SPECIFICATIONS
Resistance Range 0.24 Ω to 1 M Ω E24 series
Standard Resistance Tolerances ± 1 %, ± 2 %, ± 5 %, ± 10 %
Power Rating:
Chassis Mounted
5 W to 50 W
Unmounted 2 W to 5.5 W
Temperature Coeffi cient ± 150 ppm/°C (R > 1 Ω )
Insulation Resistance 10
6
M Ω
Total Inductance ≤ 0.1 µH
PERFORMANCE
TESTS CONDITIONS TYPICAL DRIFTS
Momentary Overload
NF EN 140 000 CEI 115_1
2 P
r
/5 s
U
s
< 2 UL
< ± (0.25 % + 0.05 Ω)
Rapid Temperature Change
NF EN 140 000 125 °C CEI 68215 Test Na
5 cycles
- 55 °C to + 125 °C
< ± (0.25 % + 0.05 Ω)
Load Life
NF EN 140 000 CEI 115_1
1000 h P
r
at + 25 °C
< ± (0.5 % + 0.05 Ω)
Humidity (Steady State)
56 days RH 95 %
MIL STD 202 Method 103 B and C
< ± (0.5 % + 0.05 Ω)
RESISTANCE VALUE IN RELATION TO TOLERANCE AND TCR
Resistance Value < 1 Ω > 1 Ω
Standard
Tolerances
± 5 %
± 10 %
Standard TCR ± 250 ppm/°C ± 150 ppm/°C
Tolerance on Request ± 1 % to ± 2 %
SPECIAL FEATURES
MODEL RCH 5 RCH 10 RCH 25 RCH 50
Power Rating-Chassis Mounted 5 W 10 W 25 W 50 W
Power Rating-Unmounted 2 W 2.5 W 4 W 5.5 W
Thermal Resistance R
TH
(j-c) 4.8 °C/W 3.2 °C/W 1.4 °C/W 0.8 °C/W
Limiting Element Voltage (V
RMS
) 160 V 250 V 550 V 1285 V
Max. Overload Voltage (V
RMS
) 320 V 500 V 1100 V 2500 V
Dielectric Strength (V
RMS
) 50 Hz, 1 Min
MIL STD 202 Method 301 10 mA Max.
2000 V 2000 V 3500 V 3500 V
Critical Resistance 5120 Ω 6250 Ω 12 100 Ω 33 024 Ω