Short-circuit protectionfor shaft furnaces
Conductive carbon dust is produced by abrasion in the shaft furnaces usually used for gas nitriding, which is a common cause of short-circuits in the heating elements. These short-circuits are only temporary, but in furnaces protected by fuses or circuit breakers, they interrupt the process until the fuse is replaced or the power switch is turned back on. This results in damage to the heat-treated products.
The Gefran GTF Xtra thyristor controller from TELE with integrated short-circuit protection monitors the electrical heating circuit. If the amperage exceeds a preset limit, the device interrupts the circuit before an overload can cause problems for production. No blown fuses must be replaced and no circuit breakers need to be switched on again. In applications where sporadic short circuits can occur, the Xtra overcurrent protection puts the system in a standby state to allow the system to be manually (locally or remotely) or automatically (through a delay) switched back on. Restart with a soft start ramp will determine whether a permanent short-circuit occured, whereby possible repair requirements are optionally signaled with an alarm.
– Fast, reliable, and secure protection for critical heating processes
– Protection of heating systems against damage due to high residual currents
– Automatic, continuous, and repeatable protection
– No need for the stockpiling and changing of fuses
– No re-closing of circuit breakers
– Greater availability, less downtime, increased productivity
– Easy re-closure with no special training or equipment required