IRVA 300-450W Metal Clad Resistor Assemblies

What are the IRVA 300-450W Metal Clad Resistor Assemblies

The IRVA is a high-power metal clad wire wound resistor assembly built around a dual-element series configuration — two IRV metal clad wire wound resistors connected in series within a single integrated assembly. By combining two resistor elements in this way, the IRVA achieves resistance values significantly higher than a single IRV unit of equivalent size, while maintaining the same rugged extruded aluminium housing construction and broad operating temperature range. This makes the IRVA particularly well suited to applications requiring both high power dissipation and high resistance values simultaneously — a combination that is difficult to achieve within the footprint of a single standard resistor.

Available in three models — IRVA 800, IRVA 1000, and IRVA 1200 — the series spans free-air power ratings of 300W to 450W, with a maximum surface temperature of 200°C. The naming convention reflects the combined wattage of the two internal IRV elements: the IRVA 800 combines two IRV400 cores, the IRVA 1000 two IRV500 cores, and the IRVA 1200 two IRV600 cores. The result is a resistance range stretching from 120Ω to 15kΩ for inductive winding and 30Ω to 7.6kΩ for non-inductive winding — covering the high-impedance discharge, braking, and charging resistor values commonly required in industrial motor control and power electronics.

Both inductive and non-inductive winding configurations are available, with the non-inductive option suited to applications where residual inductance in the resistive element would compromise performance. Tolerance options of ±1%, ±2%, ±5%, and ±10% accommodate a range of specification requirements from general industrial load control through to more defined discharge timing applications.

Dielectric withstand voltage options of AC 1500V, 3500V, 4500V, and 5400V (1 minute, maximum 2mA leakage current) provide flexibility for high-voltage bus installations, and insulation resistance is rated at 20MΩ minimum. The short-time overload capability is rated at the full nominal wattage of the assembly (800W, 1000W, or 1200W respectively) for 5 seconds — confirming the robustness required for repetitive high-energy transient duty cycles in motor control and energy recovery applications.

Characterisation testing covers thermal shock (rated power for 30 minutes followed by –25°C for 15 minutes), moisture resistance (40°C / 95% RH for 500 hours), moisture load life, and extended full-power load life at 90 minutes on / 30 minutes off for 500 hours — ensuring long-term reliability under continuous industrial duty conditions.

Model: IRVA
Resistor type: Metal clad resistor
Description: Chassis mounted assembly
Power Rating: 300W-450W
Resistance (Ω): 30~15k
Tolerance (%): ±1, ±2, ±5, ±10
TCR (ppm/C): 260 Max.

Model: IRP
Resistor type: Metal clad resistor
Description: Industrial
Power Rating: 300W~1.2kW
Resistance (Ω): 0.1~2k
Tolerance (%): ±1, ±5, ±10
TCR (ppm/C):

Model: LFH
Resistor type: Horizontal metal clad
Description: Industrial
Power Rating: 300W-2kW
Resistance (Ω): 0.1~7k
Tolerance (%): ±1, ±5, ±10
TCR (ppm/C):

Model: IRV, ULV, IRM, ULM600-1200
Resistor type: Metal clad resistor
Description: UL/CE, aluminum housed, chassis mounted
Power Rating: 600W-1.2kW
Resistance (Ω): 0.1~175
Tolerance (%): ±1, ±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):