EDM machines always carry a potential fire risk. During the EDM process, a spark is generated, which is normally shielded from oxygen by a dielectric fluid – usually oil-based. However, if oxygen reaches the spark, a fire may ignite.
In practice, the dielectric is supplied via adjustable hoses. If operators fail to position these carefully, the risk of fire increases significantly. Other factors – such as unsuitable electrodes or incorrect process settings – can also trigger a fire.
For this reason, EDM machines today are fully enclosed and equipped with fire suppression systems as standard. Nevertheless, even short fires can cause major damage: cables, motors, measuring systems, or protective bellows may be destroyed, processes interrupted and machines taken out of service. Even if the fire suppression system activates in time, the fire extinguisher must be replaced after use – inevitably resulting in downtime.
To prevent exactly this LACH DIAMANT developed a pioneering fire warning system in 1999 for all EDM machines used in PCD tool machining. At its core is an ultra-fast temperature sensor, positioned directly above the spark. When detecting a fire it immediately shuts down the generator and the dielectric supply, stops the EDM process and alerts the operator. In essence the fire is deprived of oxygen – in nine out of ten cases it extinguishes instantly.
In most situations it is sufficient for the operator to simply correct the position of a hose. The process can then continue without restarting the machine – resulting in zero downtime. If the fire persists, an independent CO₂ fire suppression system takes over.
One year later, in 2000, LACH DIAMANT went even further: a multi-stage sensor system was introduced. In addition to the temperature sensor an infrared camera has since monitored the entire machine chamber. The system first shuts down all units – and only in a second stage activates the CO₂ fire suppression system.
Today – 25 years later – every EDM machine for PCD tool machining is delivered with this triple safety concept as standard. The result: not a single customer with the installed and activated system has suffered serious fire damage since its introduction.
On the contrary – the fire warning system has prevented thousands of minor fires from escalating, without ever requiring the CO₂ fire suppression system to intervene. This not only avoids costs and downtime but has also saved countless tons of CO₂ emissions.
