Arburg Error 290: Nozzle Temperature Deviation Beyond Tolerance — Selogica Troubleshooting
Published: 2026-05-31
Arburg Error 290 is a critical interlock alarm on the Selogica control system that prevents screw rotation when the nozzle temperature deviates from setpoint by more than the programmed tolerance band (typically ±15°C for standard processing,...
Arburg Error 290 is a critical interlock alarm on the Selogica control system that prevents screw rotation when the nozzle temperature deviates from setpoint by more than the programmed tolerance band (typically ±15°C for standard processing, ±5°C for precision/high-temperature applications). The interlock protects the screw and barrel from attempting to convey and inject polymer at incorrect viscosity: under-temperature risks cold-start screw damage and excessive screw torque; over-temperature risks polymer degradation, gas generation, and in extreme cases, auto-ignition of decomposed polymer residue.
Diagnostic Protocol for Error 290
Step 1 — Verify the thermocouple: On Selogica, navigate to Diagnostics > Temperature > Nozzle Zone. Observe the actual temperature reading. If it is fluctuating wildly (±20°C in seconds — physically impossible for the thermal mass of a nozzle body), the thermocouple is failing (intermittent open circuit, or moisture in the thermocouple junction). Replace the thermocouple — use Arburg OEM or equivalent Type J or Type K thermocouple with correct bayonet-style connector for the nozzle body. Step 2 — Measure heater band resistance: Disconnect power (Lockout-Tagout). Measure resistance across the nozzle heater band leads — typical values: 20-100 Ω depending on wattage. An open circuit (infinite resistance) confirms a failed heater band. Measure insulation resistance between each lead and the nozzle body (should be >1 MΩ — low insulation resistance indicates moisture ingress or damaged ceramic insulation allowing current leakage to the nozzle body, which also corrupts the thermocouple signal through ground-loop noise). Step 3 — Verify SSR Function: The solid-state relay for the nozzle zone is typically a dedicated SSR (not multiplexed) due to the criticality of nozzle temperature control. With the machine powered and the nozzle zone calling for heat (Selogica shows 'Heating ON'), measure voltage across the SSR output terminals — should be <2 VAC (SSR ON, conducting). If line voltage appears across SSR output terminals when Selogica calls for heat, the SSR has failed open. If line voltage is absent regardless of Selogica heat command, check the DC control signal from the temperature controller to the SSR input (3-32 VDC when heat is ON, 0 VDC when OFF).
Alarm Details
| Alarm Code | 290 |
|---|---|
| Brand / Machine | Arburg |
| Severity | Critical (Interlock — Prevents Screw Rotation) |
| Component | Nozzle Heater Band / Thermocouple / SSR |
| Affected Systems | Injection Unit — Nozzle Zone |
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 |
|---|---|
| Netstal Alarm 102 | |
| Engel Alarm 405 Nozzle | |
| Sumitomo Demag Alarm 220 Nozzle |
Frequently Asked Questions
Can I override Error 290 temporarily to finish a run?
Arburg Selogica allows temporary widening of the temperature deviation tolerance band (typically from ±15°C to ±30°C) in the Setup > Temperature > Tolerance menu — but this requires supervisor-level access (password-protected). Widening the tolerance band should be used ONLY as a diagnostic tool to confirm whether the nozzle temperature is genuinely unstable (Error 290 persists even at ±30°C — hardware problem) or borderline (Error 290 clears at ±30°C — suggests a failing heater band, poor thermocouple contact, or PID tuning issue that can be addressed at the next scheduled maintenance). Never widen the tolerance band and continue production without investigating the root cause — nozzle temperature deviation of ±30°C when processing engineering polymers (PEEK, PPS, LCP) with narrow processing windows will produce out-of-spec parts (crystallinity variation, dimensional change, mechanical property loss).
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