YWZ5 Ex Family & Positioning
The family rule is simple: wheel diameter first, then thruster fitment (torque band). Within the same 200-mm wheel envelope, changing from /E23 → /E30 (or B30) only changes the thruster and spring - the mounting package stays the same.
| Model | Wheel mm | Thruster | Torque band N·m | Position / note |
|---|---|---|---|---|
| YWZ5-160/B30 | 160 | Ed30/5 Ex | 80 – 160 | Smallest Ex member |
| YWZ5-200/B30 | 200 | Ed30/5 Ex | 140 – 315 | This unit - the small-wheel Ex workhorse |
| YWZ5-250/B30 | 250 | Ed30/5 Ex | 180 – 315 | Same thruster, larger wheel |
| YWZ5-250/B50 | 250 | Ed50/6 Ex | 315 – 500 | Higher torque |
| YWZ5-300/B50 | 300 | Ed50/6 Ex | 400 – 630 | Mid-heavy |
| YWZ5-300/B80 | 300 | Ed80/6 Ex | 630 – 1000 | Heavy |
| YWZ5-400/B80 | 400 | Ed80/6 Ex | 630 – 1250 | Heavy-duty |
| YWZ5-400/B121 | 400 | Ed121/6 Ex | 1000 – 2000 | Very heavy |
Comparison: same 200-mm wheel, three different stories
| Model | Execution | Torque N·m | Thruster | Ex package | Best for |
|---|---|---|---|---|---|
| YWZ5-200/E30 | Standard | 140 – 315 | Ed30/5 | None - do not use in flammable atmosphere | Normal area |
| YWZ5-200/B30 | Ex (this unit) | 140 – 315 | Ed30/5 Ex | Thruster + sealed box + anti-static lining, certified | Hazardous area, direct retrofit of /E30 |
| BYWZ5-200/B30 | Legacy Ex (maker-specific) | 140 – 315 | BEd30/5 | Legacy Ex route, often Ex dⅠ/Ⅱ + MA | Replacing old BYWZ5 stock |
| DYW200 class | Fully Ex brake (heavier) | Higher band | Integrated Ex thruster | Whole-unit Ex, often with MA | Where full Ex certification is preferred |
Selection rule: ① match the 200-mm wheel → ② confirm 140–315 N·m covers the duty → ③ pick Ex level by Zone/gas group/T-class. Do not select on "B30 = 300" alone - B30 is a thruster code, not a torque value.
Working Principle & Safety Logic
| State | What happens | Safety meaning |
|---|---|---|
| At rest / power off (safe state) | High-strength alloy springs force both shoes against the 200-mm drum | Brake is always applied; power loss, circuit fault and hydraulic failure all end in locked drum - no separate power needed to hold |
| Energised (release) | Ed30/5 Ex thruster runs, pump builds pressure, cylinder compresses the main spring and retracts the shoes equally | Drive is free to run; PLC can monitor open/close limits (K1/K2) |
| Power / fault / emergency stop | Thruster pressure collapses; spring instantly re-applies the shoes | Prevents load drop, belt reversal and trolley drift - meets mandatory safety for explosive atmospheres |
