Heavy Duty Open Wound Resistors

​The Heavy Duty Open Wound Resistors (PHD) and Tape Wound (PT) resistors deliver strong performance in tough electrical and thermal conditions. The PHD series uses a solid ceramic core with tightly wound nickel-chrome wire. It offers continuous power ratings from 200 W to 750 W. On the other hand, the PT series features corrugated tape wrapped around the element. This design increases surface area and boosts power density. It provides continuous power from 250 W to 1000 W. Both models resist high heat, mechanical stress, and harsh environments. That’s why they work well in many industrial settings.

These resistors handle tough jobs without fail. The PHD model manages surface temperatures up to 380°C. Meanwhile, the PT model spreads heat better thanks to its tape-wound structure. Both types endure heavy electrical loads, including steady and pulse currents. They use solder-coated or tinned leads or terminal tags for strong, lasting connections. Their solid build ensures safe and stable performance. Each unit follows strict electrical rules and keeps working reliably for a long time.

Installing these resistors is quick and easy. They come with radial lead designs and standard terminal layouts. You can mount them in different ways—vertically or horizontally. Their tough design also blocks damage from shaking and handling. In addition, they meet all insulation and dielectric strength needs. This keeps the systems safe and steady. 

Heavy Duty Open Wound Resistors Product Features

• Power range (PHD): 200 W to 750 W continuous
• Power range (PT): 250 W to 1000 W continuous
• Resistance range: 0.6 Ω to 100 Ω
• Tolerance: ±1% to ±10% (alloy dependent)
• Temperature coefficient: ≤250 ppm/°C typical
• Core material: High-grade ceramic
• Element: Nickel-chrome wire
• Coating (PT): Corrugated high-temp tape
• Cooling (PHD): Open-wound air convection
• Leads: Solder-coated steel or tinned copper
• Mounts: Panel, H-bracket, HR-bracket, V-mount
• Thermal cut-outs: Optional, pre-fitted clips
• Enclosure: Optional heavy-duty steel box
• Humidity resistance: Up to 95% non-condensing
• Dielectric strength: Meets IEC insulation standards
• Vibration: High-resistance winding adhesion
• Life: 1000 h at rated power with ΔR ≤5%
• Compliance: RoHS 3, IEC 60115-1

Areas of Application

• Industrial motor braking systems
• Load banks and dummy loads
• High-energy pulse discharge
• Power-supply surge protection
• Renewable-energy inverters
• Railway traction and control
• Test and measurement benches
• HVAC and industrial heating
• Snubber and filter networks
• Heavy-duty power distribution

Whether you’re using Heavy Duty Open Wound Resistors in industrial controls, high-voltage systems, or test devices, these resistors offer solid, long-term use even in the harshest conditions.