Electronic Speed Monitor EDO
The electronic speed monitor relay EDO is used in connection with a pulse sensor to monitor the rotational speed and standstill of drives. Pulse sensors according to NAMUR EN 50227 as well as 3-wiresensors can be connected to the EDO relay. The pulse output is fed to the speed monitor relay where the pulse frequency is compared with the frequency set by the control of the relay. When the input frequency passes the set frequency the internal output relay is switched.
Warning or control equipment can be connected to this output relay and operate when the speed either increases or decreases from the setpoint. The new multi-layer contact of the output relay improves the true operation of the contact in a wide range up to 5 A and 250 V. The operation of the relay can be inhibited during start-up of the monitored drive by adjusting the start-up potentiometer to the time taken for the drive to reach operating speed.
A special design is available to meet requirements where the speed monitor unit should be installed close to the monitored drive and its pulse sensor. The design consists of speed monitor relay EDO being installed in a plastic housing, of IP65 protection. The true operation of the device can be readily observed through the transparent cover of the plastic housing.
The features of this arrangement are:
– Shortened length of screened cable between pulse sensor and relay adjustment at commissioning with visual contact to the drive.
– The output signal of the relay can be interference free transmitted to the control equipment without using the
– any number of speed monitors can be connected to only one transducer. The pre-set trip points of the individual speed monitor relays can be varied.