JSW J-AD 305 Alarm: Ejector System Overload — Diagnosis & Repair
Published: 2026-06-02
JSW J-AD 305 triggers when the ejector hydraulic cylinder's pressure transducer detects resistance exceeding the set limit during the forward (ejection) stroke. This alarm protects the ejector system and mold from mechanical damage due to...
JSW J-AD 305 triggers when the ejector hydraulic cylinder's pressure transducer detects resistance exceeding the set limit during the forward (ejection) stroke. This alarm protects the ejector system and mold from mechanical damage due to excessive ejection force. Root cause: the part is sticking in the cavity and the required ejection force exceeds the set safety threshold. Contributing factors include insufficient draft angle (<0.5°), vacuum lock (polished cavity surface with no venting), molded-in stress causing post-shrinkage grip, and mechanical binding of ejector pins or return pins.
Diagnostic sequence: 1. Check if part ejects normally in semi-automatic mode (manual ejector forward) — if manual ejection works, the issue is pressure transducer setting, not mechanical binding. 2. Measure cavity surface temperature with a contact pyrometer — if cavity is >10°C above recommended, the part is not sufficiently solidified and is gripping the cavity on ejection. 3. Check draft angle: minimum 1° on textured surfaces, 0.5° on polished surfaces. 4. Verify vacuum break (air blow into cavity at end of cooling) is functioning. 5. Inspect ejector pins for galling or bending — replace any pin with >0.05mm bend.
Alarm Details
| Alarm Code | J-AD 305 |
|---|---|
| Brand / Machine | JSW (Japan Steel Works) |
| Severity | High (Ejector Stop) |
| Component | Ejector Hydraulic Cylinder / Ejector Plate |
| Affected Systems | Part Ejection |
Troubleshooting Protocol
Identify which zone/component triggered the alarm. Record the error code, timestamp, and any measured deviation values shown on the diagnostic screen.
Power down the machine and follow Lock-Out Tag-Out procedures. Visually inspect the affected component for physical damage, loose connections, polymer leakage, or carbonized material.
Using a multimeter, check resistance/continuity on the affected circuit. Verify SSR functionality and fuse integrity. Compare readings to OEM specifications.
Replace the failed component with an OEM-approved part. Do not substitute with generic equivalents unless validated for the specific machine model and operating conditions.
Restart the machine, verify the alarm is cleared, run a test cycle, and document the root cause, repair performed, and parts replaced in the machine maintenance log.
Equivalents & Cross-References
| Equivalent / Alternate | Action |
|---|---|
| Sumitomo Demag E220 | |
| Haitian H101 |
Frequently Asked Questions
What draft angle eliminates ejection force issues?
For textured surfaces (VDI 24+), minimum 1.5° per side. For polished surfaces, minimum 0.5°. Deep-draw parts (>50mm) may require 2-3° draft regardless of surface finish. If draft cannot be increased, consider: mold release coating (TiN, DLC), air-assist ejection, or stripper plate ejection instead of pin ejection.
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References & Industry Standards
- ASTM International. Standard Specifications for Engineering Plastics & Thermoplastics. astm.org
- UL Prospector. Plastics & Elastomers Material Database. ulprospector.com
- MatWeb. Material Property Data for Engineering Thermoplastics. matweb.com
- ISO 1043. Plastics — Symbols and Abbreviated Terms. iso.org