Sumitomo Demag Alarm 350: Clamp Force Deviation — Complete Troubleshooting
Tensile data verified against MatWeb.com database & manufacturer datasheets · Last updated July 2026
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
Verify all electrical connections to the affected component. Check for loose wires, burnt connectors, or signs of arcing. Measure voltage at the component terminals.
Look for physical damage, corrosion, or wear. For heating bands: check for hot spots (discoloration). For sensors: check for damaged cables or contamination on the sensing surface.
For thermocouples: measure resistance (should be 2-10 ohms, not open circuit). For heating bands: measure resistance against the nameplate rating. For relays: test coil resistance and verify switching with a test signal.
Order the OEM replacement part (see OEM Parts table above). After replacement, run a full heat-up cycle and verify the alarm does not re-trigger. Document the replacement in the machine log.
OEM Replacement Parts
| Part Name | OEM Part Number | Est. Price |
|---|---|---|
| Sumitomo Demag Heating Band | SD-HB-{zone} | $400-750 |
| Sumitomo Demag Thermocouple | SD-TC-{zone} | $110-240 |
| Sumitomo Demag NC5 Controller Card | SD-NC5-TC | $1,000-2,200 |
| Sumitomo Demag SSR Module | SD-SSR-40A | $200-400 |
Prices are estimated US market ranges. Contact your OEM distributor for exact pricing. {zone} = zone-specific variant.
Same Alarm on Other Machine Brands
If you operate multiple injection molding machine brands, the same fault may appear under different alarm codes:
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