Technical Explanations General User Instructions for Kendrion Products of Magnet Technology 1. General 2. Environmental Requirements If present the grounding screw must be connected or the grounding of the magnet must be otherwise ensured. With devices of protection class I the protective conduc- tor connection acc. VDE 0100 must be pro- vided by the user. With devices of protection class II there is no protective conductor connection re- quired. The protection class acc. IEC 60529 in only guaranteed in the case of proper mounting to the machine and in association with plug connection via plug-in connector acc. DIN EN 175301-803 (DIN 43650).
The devices are built, tested and designed according to generally acknowledged rules of technology, in particular according to the regulations for electromagnetic devices (DIN VDE 0580/07.2000). In the case of deviations from the fixed operating and ambient conditions respec- tive measures have to be taken, e.g. higher protection class and/or a special surface protection or in the case of higher tempera- ture a special coil and special cable. The devices may only be connected to the type of voltage (alternating current) and voltage value indicated on the type plate. Before each maintenance precautions must be taken that the devices are not energised. The conducting parts, e.g.
the plug or the excitation winding of the device, must not come in contact with water. The free wire or cable ends or the plug-in con- nector must not be subject to mechanical stress (tear, squeezing). 3. Connection In the data sheets different types of con- nection for the respective devices are indi- cated. The devices may only be connected according to the data on the rating plate. Especially the voltage and the frequency have to be observed. A parallel operation of devices is common. Before connecting them it must be checked if the devices operate in phase (e.g. several inline vibrators under one shaking trough) or phase-shifted by 180° (vibration-free operation with low free load).
All devices with plug connections always operate in phase if either the left or right connection is connected to the phase. In the case of all other devices ends with the same colour resp. identically marked clamps have to be connected. During operation the amplitu- des of all devices can be electrically con- trolled (e.g. by a transformer or KENDRI- ON control units). Vibrating solenoids for direct mains con- nection carry the voltage information 230 V/50 Hz. In the case of direct connection to the mains the mechanical vibration generated is twice as high as the mains frequency be- cause each half-wave causes a magnetic pull impulse.
Shortly after the zero-crossing of the electrical current the polarity of the force field is reversed, the magnetic force being zero. Devices must not be put into operation if: • • electric leads are damaged • • the magnet housing or the coating show damages • • there is a suspected defect (after a fall or similar) Vibrating solenoids to be connected via one-way rectifiers carry the voltage in- formation G 230 V (50 Hz). An upstream one-way rectifier blocks either the positive or the negative half-wave of the alternating current. By means of a one-way rectifier we achieve a mechanical vibration in the altitude of the mains frequency.
The current flowing through the vibrating solenoid is pulsating direct current. The power decre- ase of the smaller frequency is balanced by a higher oscillation amplitude. Harmonic oscillations in the excitation frequency pre- vent the sticking of humid bulk material in conveyor channels and the blocking resp. clogging of the meshes in close meshed vibrating screens. In these cases repairs may only be carried out by specialists. Inappropriate repairs may expose users to significant hazards. If the devices are misused or wrongly con- nected no liability for potential damages will be assumed. The user assumes liability for proper and safe use.
For this reason the installation situation, ambient conditions and the like must be coordinated with the manufacturer. 4. Installation Requirements Unauthorised interference or changes of any kind, e.g. boring into the magnet hou- sing, must be avoided as they may cause functional disorders, e.g. a disconnection of the coil winding. Higher supply voltages, different rated modes, lower frequencies contrary to the specifications on the type plates or a blocked armature with AC-so- lenoids may cause serious malfunctions, e.g. thermal destruction of the excitation winding. The devices must be supplied with the re- quired rated voltage and frequency.
The voltage drop must be kept within narrow limits (normally 4 %) by proper wiring, i.e. by adequate dimensioning of the diameter. The life-cycle largely depends on external conditions (installation situation, kind of medium, intensity of load). Statements in this respect require a special agreement. The magnetic forces indicated are average values and may deviate from the list values due to natural scattering. Depending on the use the respective accident prevention re- gulations have to be observed.
When adjusting the static air gap may be selected smaller, but the nominal air gap must not be selected wider as an improper increase of the power consumption may result in a burning of the coil. An increase of the air gap requires an adaptation of the winding and results in a loss of force. The peak force F is the force measured by an equivalent direct current which equals the peak value of the alternating current with nominal air gap (DIN VDE 0580, 5.4.3.2). The amplitude force is half the peak force. 26