Metal Clad Resistors

Metal clad resistors, also known as aluminum housed resistors, are designed for high power dissipation and reliable thermal performance in demanding environments. The aluminum casing enables efficient heat transfer to a heatsink or chassis, making them ideal for applications requiring continuous load stability and compact installation.

RARA metal clad resistors cover power ratings from 10W to 8.5kW and are widely used in industrial drives, braking systems, inverters, and EV pre-charge circuits. Automotive-grade models meet AEC-Q200 requirements, while selected series are UL and CE certified for global compliance.

Compared to traditional wirewound or cement resistors, metal clad designs offer superior heat dissipation, improved mechanical durability, and flexible mounting options including chassis, baseplate, and panel configurations.

Industrial-grade aluminum-housed resistors
engineered for demanding thermal evironments
- from compact 10W chassis-mountunits to 8.5kW
high-power assemblies. Built for drives, braking
systems, EV pre-charge circuits, and more

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10W – 8.5kW
Power Range

0.1Ω – 2MΩ
Resistance Range

15+ Models
Series Available

UL / CE
Certifications

Certifications: AEC-Q200 l ISO9001 l IATF16949 l UL Listed l CE l TÜV Certified

What is a Metal Clad Resistor

A practical overview for engineers and procurement teams evaluating resistive solutions.

A metal clad resistor is a wire wound resistive element encased inside an aluminum or metal housing. The housing acts as both a heatsink and mechanical enclosure, allowing the resistor to dissipate heat efficiently when bolted to a chassis, heatsink plate, or enclosure wall.

This construction makes metal clad resistors ideal for applications that generate high levels of continuous or pulse power — situations where a conventional axial or through-hole resistor would overheat or fail. The aluminum body conducts heat away from the resistive element and into the mounting surface, extending component life and maintaining stable resistance values under load.

RARA's metal clad series covers everything from compact 10W single-element units to multi-element assemblies rated up to 8.5kW, with models available in horizontal, vertical, slim-profile, and flat-profile formats to suit a wide variety of enclosure and mounting requirements.

Construction

-Wire wound resistive element
-Aluminum or metal outer casing
-Chassis / surface mount design
-Single-element or multi-element assemblies
-Cement-encased variants available (RH10C)

Key Advantages

-Excellent heat dissipation via chassis
-High power density in compact form
-Mechanically robust for vibration environments
-Broad resistance & tolerance range
-STEP files available for thermal analysis

RARA's metal clad resistors are our most produced product line — refined over decades of industrial and automotive deployment across six continents.

Applications

Where RARA metal clad resistors are deployed in the field.

EV Pre-Charge Circuits

Used to safely pre-charge DC bus capacitors in electric vehicles and hybrid drivetrains before the main contactor closes. RARA's ARH/ARV and IRBT series are AEC-Q200 qualified for automotive-grade reliability in pre-charge applications.

Industrial Variable Speed Drives

Installed in AC and DC motor drives to limit inrush current, provide dynamic braking resistance, and protect power electronics. The IRH, IRM, and LFH series handle continuous braking loads from 60W to over 2kW in standard VFD enclosures.

Regenerative Braking & Dynamic Braking

High-power BRH/BRV, MCS, and MBVA series are engineered specifically for crane, elevator, conveyor, and servo braking systems — absorbing regenerated energy as heat during deceleration events up to 8.5kW.

Power Supplies & UPS Systems

Used as bleed resistors, discharge resistors, and load resistors in industrial power supplies, UPS units, and energy storage systems where controlled discharge of capacitor banks is required.

Automation & Robotics

Motion control systems for industrial robots, CNC machines, and automated production lines rely on chassis-mount resistors to handle peak energy from servo amplifiers during rapid stop-start cycles.

Marine & Rail Traction

Metal clad assemblies such as the RA and IRVA series are used in marine propulsion control panels and rail traction systems, where resistance to vibration, humidity, and salt exposure is critical.

Product Series

Select models from our metal clad lineup. Download individual datasheets for full specifications, dimensions, and ordering codes.

Metal Clad Resistors

What is a Metal Clad Resistor

Applications

Product Series

Why Choose RARA Metal Clad Resistors