REDARTI RED-MAG Series Thyristor-Controlled Electromagnet and Battery Charging Rectifiers are industrial power systems developed specifically to supply the high-power DC voltage and current required by electromagnets used in heavy industry, scrapyards, steel service centres, foundries and marble/mining quarries. They not only give the magnet its strong holding force (magnetic attraction) but also apply reverse polarisation (demagnetisation) at the moment of release so the part separates cleanly from the crane, delivering maximum safety and speed.
Depending on the need for uninterrupted production and safety, our systems are built in two architectures: with batteries (uninterruptible magnet power supply) or as a standard battery-less power supply. They are produced with heavy-duty air-cooled (A), water-cooled (W) or oil-cooled (O) options to suit the plant's operating environment and capacity requirements. They can be custom-built at any DC voltage (standard: 200V - 230V DC, etc.) and DC current (90 A, 120 A, 150 A and special power ratings) the user requires.
In battery-backed models, the rectifier unit and the battery bank are housed in separate cabinets for safety. To prevent loads weighing several tonnes from dropping off the magnet during a mains failure, a 15-minute backup time at full load and audible and visual alarms specific to the mains status are provided.
Reverse Demagnetisation: Why the 3-Second (-) Reverse Run Is Critical
When the magnet coils of an electromagnetic lifting system are energised, strong residual magnetism (permanent magnetisation) remains in the part. The technical importance of the (-) reverse-current function supplied as standard on REDARTI Magnet Rectifiers:
- Clearing Residual Magnetism: Whenever a 'Stop' command is given — with mains present or absent (running on batteries) — the unit automatically applies reverse current in the (-) direction (reverse polarity) for 3 seconds to stop the magnet. This instantly neutralises the residual magnetism in the part.
- Fast and Safe Load Release: Without reverse polarisation, sheet or scrap pieces keep sticking to the magnet. Thanks to the 3-second reverse run, parts are released from the crane instantly, production speed increases and the risk of accidents caused by delayed load drop is prevented 100%.
Key Features
- Battery-Backed or Battery-Less Versions: Battery-less models fed directly from the mains, or uninterruptible battery-backed power systems (with 15 min backup) that keep the load from dropping during mains failures.
- Reverse Polarity (Demagnetisation) Support: With mains present or absent, a Stop command applies 3 seconds of reverse current in the (-) direction to release the part instantly.
- Custom Power and Voltage Builds: Built to the plant's magnet power (15 kW, 22 kW, 28 kW or more) at any required DC voltage (200V - 230V DC) and current (50 A - 1000 A+).
- Versatile Cooling Architecture: Heavy-duty air-cooled (A), water-cooled (W) or oil-cooled (O) configurations built for heavy-industry conditions.
- Safe Twin-Cabinet Design: In battery-backed systems, the rectifier unit and the battery bank are built in separate dedicated cabinets for gas-release and thermal safety.
- Advanced Alarm and Warning Systems: Continuous alarm when the batteries weaken; intermittent audible/visual alarm during mains and power failures.
- Industrial Smart Control Panel: 4x20-character LCD display, menu selection buttons, adjustable battery charging current and the ability to charge the batteries even while the rectifier is stopped.
- Uninterrupted Output Assurance (EEPROM / Thermal Protection): Even in the event of an EEPROM or temperature fault, the magnet supply voltage (220V DC) is not cut, for safety, so the load does not drop.
Applications
- Iron & Steel and Metal Service Centres: Handling and stacking billets, blooms, plate and pipes with crane magnets.
- Scrapyards and Recycling Facilities: Loading and unloading heavy, loose bulk scrap metal with electromagnets.
- Foundries and Steel Mills: Safe transfer of high-temperature raw metal and castings.
- Marble and Mining Facilities: Uninterrupted supply for magnetic separators and field-generating electromagnet systems.
