INDUSTRY COMPONENT

Discharge Resistor

A discharge resistor is a passive electrical component used to safely dissipate stored energy from capacitors in capacitor bank arrays, preventing hazardous voltage buildup and ensuring operational safety.

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Component Specifications

Definition
A discharge resistor is a critical safety component in capacitor bank arrays, designed to provide a controlled path for discharging stored electrical energy after system de-energization. It prevents dangerous residual voltage that could cause electric shock, equipment damage, or fire hazards. These resistors are typically connected in parallel with capacitor banks and feature specific power ratings, resistance values, and thermal characteristics to handle discharge currents without overheating or degradation.
Working Principle
The discharge resistor operates on Ohm's Law (V=IR), providing a controlled resistance path for capacitor discharge. When the capacitor bank is disconnected from the power source, the resistor creates a circuit that allows stored energy to dissipate as heat through the resistor material. The discharge time constant (τ = R×C) determines how quickly the voltage decays to safe levels, with proper sizing ensuring discharge within required safety timeframes (typically to less than 50V within specified minutes).
Materials
High-temperature ceramic or metal alloy resistive elements (nichrome, kanthal, or ceramic composites), alumina or steatite ceramic substrates, high-temperature silicone or epoxy encapsulation, nickel-plated copper or stainless steel terminals, ceramic or mica insulation layers.
Technical Parameters
  • Power Rating 5W to 500W
  • Discharge Time ≤ 5 minutes to 50V
  • Voltage Rating 1kV to 15kV
  • Resistance Range 10kΩ to 10MΩ
  • Dielectric Strength 2× rated voltage + 1000V
  • Insulation Resistance ≥ 1000 MΩ
  • Operating Temperature -40°C to +200°C
  • Temperature Coefficient ±100 to ±500 ppm/°C
Standards
IEC 60243, IEC 60076, UL 94, ISO 9001, DIN EN 60115

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Discharge Resistor.

discharge resistor capacitor bank safety electrical discharge high voltage resistor energy dissipation safety component IEC standards power resistor Discharge Resistor in Electrical Equipment Manufacturing

Parent Products

This component is used in the following industrial products

Capacitor Bank Array

A modular assembly of multiple capacitor banks designed for industrial power factor correction applications.

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Engineering Analysis

Risks & Mitigation
  • Electric shock from residual voltage
  • Thermal runaway from insufficient power rating
  • Insulation breakdown from moisture ingress
  • Mechanical failure from vibration stress
  • Corrosion of terminals in harsh environments
FMEA Triads
Trigger: Overheating due to excessive discharge current
Failure: Resistance value drift or open circuit
Mitigation: Implement thermal protection, use resistors with adequate power derating, and ensure proper ventilation
Trigger: Moisture absorption in encapsulation
Failure: Reduced insulation resistance leading to leakage current
Mitigation: Use moisture-resistant materials, conformal coating, and sealed enclosures
Trigger: Mechanical stress from vibration
Failure: Cracked resistive element or broken connections
Mitigation: Secure mounting with vibration dampeners and use flexible lead connections

Industrial Ecosystem

Compatible With

Interchangeable Parts

Compliance & Inspection

Tolerance
Resistance tolerance typically ±5% to ±10%, power rating derated by 50% at maximum operating temperature
Test Method
High-pot testing at 2× rated voltage + 1000V for 60 seconds, resistance measurement at 25°C ±5°C, thermal cycling from -40°C to +125°C for 100 cycles, humidity testing at 85% RH and 85°C for 1000 hours

Buyer Feedback

★★★★☆ 4.8 / 5.0 (15 reviews)

"Standard OEM quality for Electrical Equipment Manufacturing applications. The Discharge Resistor arrived with full certification."

"Great transparency on the Discharge Resistor components. Essential for our Electrical Equipment Manufacturing supply chain."

"The Discharge Resistor we sourced perfectly fits our Electrical Equipment Manufacturing production line requirements."

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Frequently Asked Questions

Why are discharge resistors necessary in capacitor banks?

Discharge resistors are essential for safety, preventing hazardous voltage buildup that could cause electric shock, equipment damage, or fire when capacitors retain charge after system shutdown.

How do you calculate discharge resistor values?

Resistance is calculated using R = t / (5×C), where t is desired discharge time (seconds) and C is capacitance (farads), ensuring voltage drops to safe levels (typically <50V) within required timeframes.

What happens if a discharge resistor fails?

Failure can leave capacitors charged at dangerous voltages, creating shock hazards, potential arc flashes during maintenance, and possible capacitor dielectric breakdown from sustained overvoltage.

Can I contact factories directly?

Yes, each factory profile provides direct contact information.

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