Sumitomo Demag Alarm 350: Clamp Force Deviation — Complete Troubleshooting
Published: 2026-05-28
Sumitomo Demag Alarm 350 indicates that the measured clamp force deviates from the setpoint by more than the safety margin (±8% on most SD machines). This can mean either insufficient clamp force (flash risk during injection) or excessive clamp...
Sumitomo Demag Alarm 350 indicates that the measured clamp force deviates from the setpoint by more than the safety margin (±8% on most SD machines). This can mean either insufficient clamp force (flash risk during injection) or excessive clamp force (mold and tie bar damage).
Step-by-Step Diagnostic
1. Verify actual clamp force with a magnetic-base dial indicator on the tie bar (measure tie bar stretch and convert to force using Hooke's Law). 2. Check tie bar strain gauge calibration — perform a zero-point reset following the machine manual's procedure. 3. Inspect mold height setting — incorrect mold height forces the clamping system to compensate, triggering the alarm. 4. Check hydraulic clamp pressure transducer — a failing transducer provides incorrect pressure feedback to the controller. 5. Inspect tie bar nuts for loosening — a single loose tie bar shifts the entire clamp force distribution.
Alarm Details
| Alarm Code | 350 |
|---|---|
| Brand / Machine | Sumitomo Demag |
| Severity | Critical (Mold Protection — Immediate Stop) |
| Component | Clamp Force Transducer / Tie Bar Strain Gauge |
| Affected Systems | Clamping Unit — Force Control Loop |
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 |
|---|---|
| engel-alarm-510 | |
| krauss-maffei-mc100-hydraulic-system |
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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