Goudsmit Magnet Safety

Permanent magnets and electromagnets can both be switched, but there is an important difference:

Permanent magnets are compact and always active - they maintain their magnetic force;

Electromagnets switch quickly, without wear, and can also lift heavy loads, but if the power supply is interrupted, there is a risk of the load dropping - therefore, electric lifting magnets must always be equipped with a backup system, which can be expensive.

Goudsmit MagnetsSwitching Systems

Monostable magnet systems remain activated or deactivated only as long as they are supplied with an electrical or pneumatic switching signal. Once this signal is lost, the system switches back to the "idle state." Electromagnets are always monostable and are always off when idle. Permanent systems can be either on or off when idle.

Bistable magnet systems are switched on and off by a switching signal and remain in that state until a subsequent switching signal is received. For lifting and handling applications, bistable systems are safer than monostable systems because they are effectively off, so they do not accidentally attract steel plates. Bistable magnetic systems are always composed of permanent magnets (or a combination of permanent and electromagnets).

All Goudsmit lifting systems are bistable, except for the electro-permanent lifting magnet EHPM.

Goudsmit MagnetsSafety Factors

The specified maximum separation force for lifting and handling magnets (the force required to pull the magnet from the product) applies to flat plates of at least a specific thickness. If the sheets are thinner or the surface is rougher or dirtier, a lower force is required. In practice, the maximum holding force (separation force) is therefore not always achievable.

For the recommended working load, in addition to these factors, a safety factor compliant with the EN 13155 standard must be included. Depending on the magnet system, this is:

Factor 2 for electromagnets and vacuum;

Factor 3 for permanent and permanent systems.

Always ensure that no one walks under the lifted load. If this cannot be avoided, additional mechanical support (fall protection), such as chains, must always be present around the load.