Wittmann Battenfeld Alarm B12: Temperature Deviation Zone 3 — Diagnostic Guide
Tensile data verified against MatWeb.com database & manufacturer datasheets · Last updated July 2026
Published: 2026-05-28
Wittmann Battenfeld Alarm B12 indicates a temperature deviation exceeding ±5°C in barrel zone 3 (metering zone). This is a quality-critical alarm — metering zone temperature inconsistency directly affects melt homogeneity, shot weight...
Wittmann Battenfeld Alarm B12 indicates a temperature deviation exceeding ±5°C in barrel zone 3 (metering zone). This is a quality-critical alarm — metering zone temperature inconsistency directly affects melt homogeneity, shot weight consistency, and part dimensional stability.
Diagnostic Protocol
1. Check heater band continuity with a multimeter (power off, LOTO). 2. Verify thermocouple reading against a calibrated external probe at setpoint. 3. Inspect heater band for carbonized polymer bridging the band and barrel (creates a thermal short). 4. Check SSR (solid state relay) output — a failing SSR can cause intermittent heating. 5. Verify cooling fan function on the barrel zone — inadequate cooling causes temperature overshoot, then the controller overcorrects, creating oscillation.
Alarm Details
| Alarm Code | B12 |
|---|---|
| Brand / Machine | Wittmann Battenfeld |
| Severity | High (Quality Risk — Part Inconsistency) |
| Component | Barrel Heater Band / Thermocouple Zone 3 |
| Affected Systems | Temperature Control — Metering Zone |
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 |
|---|---|---|
| Wittmann Heating Band | WB-HB-{zone} | $380-700 |
| Wittmann Thermocouple | WB-TC-{zone} | $100-200 |
| Wittmann B8 Control Module | WB-B8-CTRL | $900-1,800 |
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-405 | |
| arburg-error-290 |
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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