The deviation switch is a product used to detect the amount of belt deviation of the belt conveyor, serving as a safety protection device that automatically alarms and stops the conveyor in case of belt deviation.
Introduction
The deviation switch has two angle levels, commonly used are: the first level angle is: 10, 12, 20, and the second level angle is: 30, 35, 45.
Basic Principle
When the conveyor belt deviates during operation, the conveyor belt touches the switch roller and causes the roller to deflect. When the deflection angle of the roller reaches the 1st level switch angle, the switch sends out an alarm signal. When the conveyor belt deviates severely and reaches the 2nd level switch angle, the switch sends out a stop signal, achieving the automatic shutdown of the conveyor belt deviation fault. When the deviation fault is eliminated and the conveyor belt operates normally, the switch roller can automatically reset to the initial state.
Installation and Adjustment
1. The deviation switch is installed on both sides of the conveyor belt, and the roller should be perpendicular to the plane of the conveyor belt edge, with the sides of the conveyor belt located at 1/3 of the roller height.
2. The distance between the deviation switch roller and the normal position of the conveyor belt should be 50-100mm.
3. The number of deviation switches should be determined according to the length, type, and layout of the conveyor. Generally, they should be set at the head, tail, convex arc section, concave arc section, and in the middle of the conveyor. (Note: When the conveyor is long, one pair should be set every 30-35 meters in the middle of the conveyor.)
4. The deviation switch should be connected to the conveyor intermediate frame through the installation bracket. The switch bracket should be welded to the conveyor frame after the conveyor is installed, and the deviation switch is fixed to the deviation switch bracket with bolts.
Scope of Application
Two-level deviation switches are used for regular belt conveyors: underground, ropeway-supported belt conveyors: ship loading and unloading systems; stacking/retrieval conveyors; inclined and shuttle conveyors; cranes, excavators, and crane arm limiters; skirt edge feeders/conveyors: heavy-duty limit switches detect the amount of belt deviation, serving as a protective device for automatic alarm and shutdown control of the belt machine. Widely used in various belt conveyor equipment in fields such as metallurgy, coal, cement building materials, mining, power, ports, metallurgy, and chemical industry.
Classification of Deviation Switch
The deviation switch has ordinary type, junction box type, and address coding type.
Ordinary type: It is the above-mentioned two-level deviation switch;
Junction box type: Based on the ordinary deviation switch, it comes with a waterproof junction box, and the on-site control cable can be directly connected to the junction box, eliminating the faults caused by cable joints getting wet or being falsely connected.
Address coding type: Based on the ordinary deviation switch, it integrates XLline field bus technology, realizing address coding function. It is suitable for long belt conveyors as remote monitoring of the operating conditions of on-site equipment, solving the inconvenience caused by workers looking for fault points.
The address coding type two-level deviation switch is connected to the comprehensive protector (gateway) through the XLline field bus, supporting up to 128 addresses, and the same address can be used for multiple switches simultaneously. Its greatest feature is that only a two-core cable is required to complete data transmission at the same time without power supply.
The XLline field bus can eventually be flexibly connected to PLC and computer interfaces of major manufacturers.
Technical Specifications
1. Rated voltage: AC380V
2. Rated current: 5A
3. Number of contacts: Two sets of independent normally open and normally closed contacts
  ;4. Shell protection level: DT type dust-tight shell, protection level IP67
5. Ambient temperature: -25 to 80°C
6. The switch can work under vibration conditions with a frequency of 10-60Hz and an amplitude of 0.75mm (10g)
7. Dimensions: Shell L×W×H (mm) 190×135×100.
8. Operating force: 5-7kg
9. Communication interface: RS485 address coding network communication
