86475-11S Reliance Electric Three-Phase SCR Rectifier Stack

The 86475-11S, also referred to as 8647511S, is a robust three-phase fully controlled SCR rectifier stack developed by Reliance Electric, currently under Rockwell Automation. It acts as a core AC-to-DC power conversion component specially designed for medium horsepower three-phase DC drive systems. By adopting phase-angle control technology, this unit converts three-phase alternating current into adjustable direct current, which is widely used for armature and field regulation of industrial DC motors. First launched in the 1980s, this model has been discontinued by the original manufacturer. All available products on the current market are new surplus stock, professionally refurbished units or tested second-hand products. The 11S suffix represents a configuration with 11 amperes continuous current rating and left-hand mounting structure, equipped with built-in heat dissipation assemblies and complete gate drive circuits to adapt to various legacy industrial drive equipment.

The model number follows the standard naming rule of Reliance Electric rectifier series. The code 86475 stands for the product family of three-phase SCR rectifier stacks. The number 11 indicates the rated continuous DC output current of 11 amperes. The suffix S denotes left-hand mounting orientation and standard industrial configuration.

This rectifier stack supports three-phase AC input of 230 VAC, 460 VAC or 575 VAC, and works normally at both 50 Hz and 60 Hz power frequency. Its DC output voltage ranges from 0 to 600 VDC, with 11 amperes continuous current and 30 amperes peak current. The internal circuit adopts three-phase fully controlled bridge topology, consisting of six SCR modules and three freewheeling diodes. The power conversion efficiency maintains above 97% under full load operation. When tested at 1000 VDC, the insulation resistance is no less than 500 megohms. The component can withstand a maximum di/dt of 100 A/μs and a maximum dv/dt of 500 V/μs. Integrated protective devices include RC snubber circuits, metal oxide varistors and thermal cutoff switches, which effectively protect the unit from damage caused by overvoltage, overcurrent and overheating.

The 86475-11S features a left-hand mounting bracket with four mounting holes for stable installation inside drive enclosures and control cabinets. It is fitted with vertical finned aluminum heat sinks mounted on a heavy-gauge steel base, which delivers excellent heat dissipation performance during long-term high-load operation. A dedicated gate drive printed circuit board is installed on the top of the main body, integrated with pulse transformers, resistors and diodes to ensure stable triggering of each SCR module. All external connection terminals are made of tin-plated copper material, featuring low contact resistance and strong corrosion resistance. The overall structure is rated IP20, which can prevent dust accumulation and avoid accidental contact with internal live parts. The whole unit can resist vibration from 10 Hz to 1000 Hz with acceleration up to 5 g. The approximate overall dimensions are 254 mm by 152 mm by 102 mm, and the weight is about 1.8 kg to 2.0 kg. Its unified installation size enables direct replacement of matching legacy rectifier stacks.

The applicable operating temperature ranges from minus 20 degrees Celsius to plus 85 degrees Celsius, and short-time operation up to plus 100 degrees Celsius is allowed. The storage temperature covers a range from minus 40 degrees Celsius to plus 85 degrees Celsius. It can operate in the environment with relative humidity between 5% and 95% on the premise of no condensation. The unit can be installed and used normally at an altitude up to 1000 meters without performance derating. Derating treatment is required for applications at altitudes higher than 1000 meters to guarantee safe and stable operation.

This product is fully compatible with Reliance GTS, MaxPak and S4 series three-phase DC drives. Designed for left-hand installation positions, it is the ideal replacement part for maintenance and retrofit projects of old-style drive systems. It is widely applied in industrial equipment such as conveyors, plastic extruders, material mixers, industrial fans and water pumps. It is suitable for general industrial working conditions that require stable three-phase AC to DC conversion and reliable motor speed regulation.

Original production of the 86475-11S has been completely stopped. The mainstream supplies in the market include new surplus products, refurbished units and inspected used units. Refurbished products go through complete disassembly, deep cleaning, replacement of aging components and a minimum 4-hour full load test to make sure all technical indicators meet the original factory standards. The standard warranty period is 12 months, covering quality defects of raw materials and workmanship under normal operating conditions. The warranty does not cover damage caused by unauthorized disassembly and modification, incorrect installation, overvoltage, overcurrent, mechanical impact or operation beyond the rated environmental parameters.