The same units can be used on conveyors of different widths by simply changing the length of the two plastic coated steel wires. Installation is greatly simplified since only the plastic coated steel wires are underneath the conveyor belt. The switch enclosures are mounted at the side of the conveyor eliminating the need to carry out work underneath the conveyor belt.
The complete transducer comprises of two identical units, one positioned each side of the conveyor to be protected. This device prevents belt misalignment or ‘wander’, which can cause a conveyor belt to turn over causing considerable damage and spillage of the conveyed material. Belt alignment protection is provided by a pair of vertically mounted nylon 66 or ceramic rollers. When belt mis-alignment occurs, one of the rollers is bought into contact with the edge of the belt which activates a rotary switch housed in the associated unit.
The mechanism is arranged such that either latching or non-latching operation is possible. The belt tear protection facility is provided by dual plastic coated steel wires each set at an angle to suit the curvature of the conveyor belt.
The Belt Alignment and Tear Unit is fitted with a rotary switch with one normally open and one normally closed contact. The contact ratings are as follows:
16 Amps;250 volts ac;3 kw.
The Belt Alignment and Tear unit is deemed intrinsically safe to the ATEX standard EN 60079-11:2012 Explosive Atmospheres-Part 11:
Equipment protection by intrinsic safety ”i” section 5.7 ‘Simple Apparatus’. The switch contacts can be used to switch an intrinsically safe circuit with the following characteristics: Ui max = 50 volts; Ii max = 100ma.