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The Braking Resistor for Mining Truck and Oilefield is an energy absorption device designed for extreme heavy loads, high impact, high dust content, and wide temperature range (-40℃ to +60℃) conditions. It is mainly used in the electric braking systems of large mining electric-wheel dump trucks (with a load capacity of 100 to 400 tons), oilfield drilling rig winches, well servicing rigs, top drive devices, and pumping units, etc. These equipment have extremely large rotational inertia (the kinetic energy during downhill travel with full load is equivalent to that of several tons of TNT). Ordinary braking resistors simply cannot withstand such huge instantaneous power and energy. Therefore, the Braking Resistor for Mining Truck and Oilfield needs to possess ultra-high power density, extremely strong mechanical strength, excellent heat dissipation design, as well as explosion-proof, dust-proof, and vibration-resistant capabilities.
The resistive elements are made of specially designed alloy resistors or stainless steel grid resistors. They are combined into resistive modules through multi-layer stacking or welding. Each module can withstand an energy impact of up to several megajoules and has a peak power of several megawatts (for short periods, such as 30 seconds). The heat dissipation method usually employs forced air cooling, equipped with large-flow axial fans or centrifugal fans. The air duct design can effectively blow away the dust adhering to the surface of the resistors. The shell is made of thickened steel plates, welded firmly, and has a protection level of IP54 or higher. The air intake is equipped with a high-efficiency filter screen (which can be cleaned or replaced). The Braking Resistor for Mining Truck and Oilefield is usually installed on the rear platform of the mining truck or the top of the drilling rig's machine room. The working environment is extremely harsh, so the connecting cables use oil-resistant, high-temperature-resistant, and wear-resistant silicone rubber cables, and the terminals are made of stainless steel.
In mining electric-wheel trucks, when the driver depresses the brake pedal, the electric wheel motor switches to generator mode, generating current which is controlled by a chopper and flows into the brake resistor box. This converts kinetic energy into heat and dissipates it, achieving wear-free electric braking and significantly reducing the consumption of mechanical brake pads. In oilfield drilling rigs, when the traveling block is lowered and the drill string is pulled in, the winch motor regenerates electricity, also relying on the brake resistor to absorb energy. These applications require the Braking Resistor for Mining Truck and Oilfield to be able to withstand frequent braking (a mining truck may brake hundreds of times in one shift) without experiencing resistance drift or open-circuit failure.
Selection requires providing the peak braking power of the motor, braking duration, braking usage rate, maximum ambient temperature, altitude (affecting heat dissipation efficiency), installation space dimensions, vibration level (mining trucks require 3g to 5g acceleration). At the same time, the temperature rise of the resistor must be controlled within the allowable range (typically the surface temperature ≤ 400°C) to prevent the ignition of coal dust or oil. Maintenance-wise, the resistor surface must be cleaned regularly, the operation of the fan checked for normality, the fasteners checked for looseness, and the insulation resistance tested (should be ≥ 1MΩ). Due to the special nature of mining and oilfield conditions, these resistors often require customized design rather than standard off-the-shelf products.
RST Electric also offers various types of Braking Resistors. Please come and consult for purchase!
