Sumitomo Demag E330 Injection Pressure Spike Alarm — Diagnostics & Repair
Tensile data verified against MatWeb.com database & manufacturer datasheets · Last updated July 2026
Published: 2026-06-08
Sumitomo Demag alarm E330 is triggered when the injection pressure transducer detects a pressure spike exceeding the maximum setpoint during the injection phase. This is a protective alarm — the control system is preventing hydraulic or...
Sumitomo Demag alarm E330 is triggered when the injection pressure transducer detects a pressure spike exceeding the maximum setpoint during the injection phase. This is a protective alarm — the control system is preventing hydraulic or mechanical damage from an overpressure event. The spike can be caused by: (a) a blocked nozzle or sprue bushing — solidified material from a previous short shot or cold slug has obstructed the flow path, (b) a frozen gate — the gate has solidified before the mold is fully packed, causing the injection pressure to spike against the solid material, (c) a mechanical obstruction — a foreign object or separated mold component has blocked the cavity, or (d) a failing pressure transducer that is reading incorrectly (reporting a spike that did not actually occur). The first diagnostic step is to check whether the spike is real or a transducer artifact.
Diagnostic sequence: (1) Purge the barrel manually and observe whether material flows freely from the nozzle — if it does not, the nozzle is blocked. Clean or replace the nozzle tip. (2) With the mold open, run an air shot and observe the injection pressure profile — if the pressure traces normally without the mold, the issue is in the mold (blocked gate, runner, or cavity), not in the machine. (3) Inspect the mold for a blocked gate or a short shot from the previous cycle that was not ejected. (4) If the pressure transducer is suspect, swap it with a known-good transducer from another machine or compare its reading against a calibrated pressure gauge at the nozzle.
Alarm Details
| Alarm Code | E330 |
|---|---|
| Brand / Machine | Sumitomo Demag |
| Severity | High (Machine Stop) |
| Component | Injection Pressure Transducer / Hydraulic Proportional Valve / Mold Blockage |
| Affected Systems | Injection Unit — Injection Pressure Closed-Loop Control |
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 E420 Injection Pressure Limit | |
| Arburg 310 Pressure Deviation |
Frequently Asked Questions
E330 trips on every cycle — but only with one specific mold. What does this indicate?
The issue is in that specific mold — not the machine. The most common causes are: the gate size is too small for the material viscosity (the gate freezes before the cavity is packed), the runner system has a restriction (partially blocked), or the mold has a mechanical obstruction in one cavity. Inspect the mold thoroughly — start with the gate and runner before suspecting cavity damage.
Can a failing heater band cause an injection pressure spike?
Yes — indirectly. If a nozzle heater band fails, the material in the nozzle tip cools and partially solidifies between cycles. On the next injection, the injection unit must push against this cold slug — the pressure spikes until the slug shears and flows. The E330 may trip during this spike. If the alarm occurs only on the first cycle after a pause (e.g., after a shift change or machine stoppage), suspect a nozzle temperature issue.
Related Diagnostics & Materials
Netstal Alarm 102: Heating Zone Temperature Out of Range...
Netstal Alarm 102 occurs when the actual temperature of a specific heating band in the injection barrel deviates...
Arburg Error 320: Barrel Heating Control Failure -...
Arburg Error 320 is a critical interlock alarm triggered when the Selogica controller detects no current flow to one...
Engel Alarm 405: Screw Recovery Time Exceeded - Diagnostics & Fix
Engel Alarm 405 is generated by the CC300 controller when the screw recovery (plastication) time exceeds the maximum...
Netstal Alarm 301: Mold Protection Force Exceeded -...
Netstal Alarm 301 is one of the most critical safety alarms in injection molding—it triggers when the clamping unit...
Sumitomo Demag Alarm 220: Clamp Force Not Reached -...
Sumitomo Demag Alarm 220 triggers when the NC5 (or NC5 plus) controller detects that the actual clamping force...
KraussMaffei Alarm MC45: Injection Pressure Limit...
KraussMaffei Alarm MC45 is generated by the MC6 controller (KM's latest-generation control platform) when the...
Wittmann Battenfeld Alarm B6: Ejector Position Fault -...
Wittmann Battenfeld Alarm B6 triggers on the Unilog B8 (or B6/B6P) controller when the ejector system fails to reach...
Arburg Error 290: Screw Rotation Speed Deviation -...
Arburg Error 290 is triggered by the Selogica controller when the actual screw rotation speed (measured by the screw...
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