Dings Magnetic Group Self-Cleaning Electro Overhead Magnets - Manual (Page 7)

Revised May 19, 2014
Electrical Connections
Electro Overhead Magnets operate on direct current. The DC connections to the magnet are
made in the terminal box located on one side of the magnet. Polarity is not important. The DC
current is supplied by a rectifier. Do not ground the DC circuit or the magnet will be damaged.
Switching should be done on the input (AC) side of the rectifier. This will avoid excessive
arcing and high inductive voltages which develop when a magnet coil circuit is opened.
Wiring should be in accordance with prevailing local and national electric codes. Wire size
should be based on the nameplate wattage. As magnet coil warms, the wattage will decrease.
Voltage of magnet terminals should be within + 5% of nameplate voltage. If the unit is a self
cleaning magnet, check that the motor wiring is correct for all the power supplied. Make sure
the nuts on the motor wiring tabs are all tight. When operating properly, the magnet will run
hot. The magnet coil is immersed in a special oil which allows it to operate at an extremely
high magnetic intensity. Oil continuously circulates in and around all parts of the coil windings.
This circulation allows even heat distribution for longer coil life. This heat is transferred to the
magnet case for dissipation.
NOTE: Some self-cleaning models have a junction box mounted on the frame. This box is
pre-wired to the terminal box on the magnet body. Connect DC power to the junction box as
described previously. After electrical connections have been completed, connect AC power to
the motor thru a motor starter. Be sure line voltage and frequency agree with voltage and
frequency shown on motor nameplate. Check the cleaning belt for correct travel direction.
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