Automatic fan control of drying chamber
In industrial drying chambers it is mandatory to ensure an automatic start for the fans to maintain the air circulation inside the chamber when the dryer or heater is started. At the end of the process those fans should continue to work some extra time and stop automatically after a preset time. Monitoring the main dryer load current, makes it easy, to detect process start and process end. At the start of the machine/plant for the first time it may be helpful to start the blowers to remove dust and dirt from the air tubes.
The monitoring relay, E3IF500mAAC20 of the ENYA series, senses the main load current directly (max. 16A AC) in the supply line. At a free settable minimum tripping level in the range of 50mA AC up to 500mA AC, the monitoring relay starts the timer for the time the auxiliary aggregate should run longer then the main unit. During that time the min LED indicates the running timer. After timing out the LED is on and the relay LED OFF indicates the status of the output relay. If the load current exceeds the min trip level + 5% hysteresis, the relay switches to the on state immediate. The start time is an extra function to start the auxiliary drive for a set time when the monitor/machine is powered up. That enables the auxiliary unit to operate independent of the load current.
– Automatic start and delayed stop of auxiliary aggregates
– Direct load current measurement up to 16A AC
– Simple operation and setup
– Two independent times for delayed stop and start preparation process.