CONVEYOR SAFETY
Conveyor Belt Safety Devices
Protection along a belt conveyor comes down to four things: the pull cord must stop it, misalignment must be corrected, slip must be measured, and a rip must trip the line. Laiyuan LYSH series shares one mounting and wiring logic across these switches, and can be upgraded to bus address coding.
Pull-cord switches
Pulling the wire rope at any point along the line trips the conveyor; manual reset. Die-cast aluminium housing as standard, 304 stainless steel for corrosive environments, and an integrated address-coded version when location reporting is required.
| Model | Type | Key parameters |
|---|---|---|
| LYSHHPLS | Bi-directional pull-cord switch | Operating force >70N, 2 SPDT contacts, AC380V/5A & DC30V/3A, IP65, 1.7 kg |
| LYSHHLS-B | Stainless steel bi-directional | 304 stainless enclosure, same contact ratings, 2.6 kg |
| LSSH-LS-C | Magnetic bi-directional | AC220V/0.5A & DC30V/0.3A, 1.5 kg, one or two cable entries |
| LYSHLS-DZ | Integrated address-coded | Bus-powered, ID 0–254, infrared setting, 2 dry contacts |
Two-stage misalignment switches
When the roller deviates to stage 1 the switch alarms, at stage 2 it trips, avoiding edge wear and spillage. Ultimate angle 75°, operating force >30N measured at the roller tip.
| Model | Type | Key parameters |
|---|---|---|
| LYSH-PK-15 / LYSH-PK-20 | Two-stage misalignment | 15°/30° or 20°/35°; die-cast aluminium, powder coated, 1.75 kg |
| LYSHPK-B | Stainless steel two-stage | Full 304 stainless die-cast, heat, salt-fog and corrosion resistant, 2.9 kg |
| LYSHPK-DZ | Integrated address-coded | Bus-powered, polarity-free wiring, ID 0–254, 2 dry contacts |
Speed and slip detection
Non-contact sensing of the tail pulley, compared with a set point to output alarm or trip; suitable for variable-frequency drives and long conveyors.
| Model | Type | Key parameters |
|---|---|---|
| JXDH-0706-Z | Photoelectric speed detector | AC85–240V, 5–4500 RPM, accuracy better than 99%, alarm range 0–199%, two independent outputs |
| LYSH-DHJC | Speed / slip detector | AC220V or DC24V, sensing distance 5–10 mm, 20–4500 RPM, 4–20mA optional |
| LYSH-DHSJ | Belt-speed slip detector | Two-wire electronic switch, output reverses below 70% of set point, direct to PLC |
Material flow and level detection
The paddle stops when it meets material and outputs a material-present / material-absent signal, used for blockage, no-load and bin level control.
| Model | Type | Key parameters |
|---|---|---|
| LYSH-YHLW-1 | Rotary paddle level detector | AC220V, paddle 5 rpm, torque 0.05–0.1N·m, G1-1/2 thread or flange, IP65 |
| LYSHLW-JC | Extended rotary paddle | Shaft adjustable 1000–1800 mm, vertical mounting only, for tall bins |
Rip detectors and heavy-duty limit switches
| Model | Type | Key parameters |
|---|---|---|
| LYSH-YHZL | Rip detector | Operating force ≥20N, 1 NO + 1 NC, AC220V/5A, plastic-coated wire rope barrier, 7 kg |
| LYSH-XW-GL | Heavy-duty limit switch | Bi-directional 20°, ultimate 120°, operating force 10N, auto reset, 2 SPDT contacts |
CAN ADDRESS CODING SYSTEM
Turn scattered switches into a network that reports location
In a conventional scheme dozens of pull-cord and misalignment switches are wired individually back to the control room, and an alarm only says “something is wrong in that section”. The LYSH bus scheme daisy-chains address encoders on one communication cable, so the alarm carries the switch type and its position, and uploads to DCS or third-party systems over MODBUS.
LYSH80 controller
RS485/MODBUS host interface, CAN bus carrying 254 encoders, up to 10 km, alarm-first or ID-order polling.
LYSH100 controller
Powers 254 encoders and collects up to 508 switch signals; tree, star and line topologies.
LYSH-ZJ repeater
Isolated input and output, 1.2 km per span, up to 20 spans, 4-digit LED indicating bus device status.
LYSH-BM-A encoder
ID 0–254 settable, LED shows switch type and ID, two built-in relays, accepts nine types of safety switch.
For hazardous areas, Ex d IIB T4 Gb repeaters and encoders are available (YT-DZZJ-FB / YT-DZBM-A-FB).