ARH / ARV 60-500W Automotive Series Metal Clad Resistors

What are the ARH / ARV 60-500W Automotive Metal Clad Resistors?

The ARH and ARV are automotive-grade wire wound metal clad resistors engineered specifically for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs). AEC-Q200 qualified and available across nine power ratings from 60W to 500W, this series represents one of the most comprehensive automotive-grade metal clad resistor families available — scaling from compact pre-charge resistor applications all the way through to high-power discharge and braking duties in large-format EV and energy storage platforms.

The ARH (Horizontal) and ARV (Vertical) designations refer to the mounting orientation of the chassis bolt pattern, giving system designers the flexibility to select the configuration that best fits their enclosure layout and heatsink arrangement. Both variants share identical electrical characteristics and dimensions, with the extruded aluminium housing providing robust mechanical protection while serving as an integrated heatsink when bolted to a chassis surface — efficiently dissipating the thermal load generated during pre-charge cycles, braking events, and other high-energy transient duties.

The primary function of the ARH/ARV in EV and HEV architectures is to control inrush current through Power Relay Assemblies (PRAs), safely limiting the surge current that flows when a high-voltage DC bus capacitor is pre-charged before the main contactor closes. Special automotive-grade flying leads are available as a standard option, matched to the current and voltage demands of each power rating. Both inductive and non-inductive winding configurations are offered, with the non-inductive option suited to snubber and high-frequency switching applications where residual inductance would degrade transient suppression performance.

A High Power variant (suffix H) is also available for the 100, 120, and 200W models, delivering 150W, 170W, and 250W respectively in free-air operation — useful where heatsink mounting is not practical and maximum power density in free air is required.
The ARH/ARV series undergoes a comprehensive automotive-specific qualification test programme beyond standard industrial characterisation. In addition to the usual short-time overload (5× rated power for 60W; 10× rated power for 80W–500W), moisture resistance, thermal shock, vibration, and load life tests, the series is also validated through an automotive operation test (rush current cycling up to 15,000 cycles at +85°C with specified capacitance), low temperature operation (–40°C rush current testing for 3 hours), thermal cycling (207 cycles, –40°C to +85°C), and a combined vibration-with-thermal-cycling test (–40°C to +85°C, 41 hours per axis) — confirming the structural and electrical integrity required for the lifetime demands of automotive chassis installations.

Pre-charge application note: In EV and HEV drivetrain architectures, the ARH/ARV is placed in series with the main positive contactor. When the ignition cycle begins, current flows through the resistor to charge the DC link capacitors to near battery voltage before the main contactor closes — eliminating the damaging inrush spike that would otherwise occur.

Model: ARH, ARV
Resistor type: Metal clad resistor
Description: Automobile, pre-charge
Power Rating: 60W-500W
Resistance (Ω): 0.2~3k
Tolerance (%): ±0.5, ±1, ±2, ±5, ±10
TCR (ppm/C): 260 Max.

Model: IRHC
Resistor type: Metal clad resistor
Description: Aluminum housed, chassis mounted
Power Rating: 40W, 60W, 100W
Resistance (Ω): 10~1k
Tolerance (%): ±5, ±10
TCR (ppm/C): 260 Max.

Model: IRBT
Resistor type: Metal clad resistor
Description: Automotive
Power Rating: 60W
Resistance (Ω): 1~1k
Tolerance (%): ±5, ±10
TCR (ppm/C): 260 Max.

Model: IRB
Resistor type: Metal clad resistor
Description: Metal clad economy
Power Rating: 60W~120W
Resistance (Ω): 0.1~1.3k
Tolerance (%): ±2, ±5, ±10
TCR (ppm/C): 260 Max.

Model: SFH/SFV
Resistor type: Metal clad resistor
Description: Industrial
Power Rating: 60W~200W
Resistance (Ω): 0.1~2.2k
Tolerance (%): ±1, ±5, ±10
TCR (ppm/C):