A 400-ton hydraulic press keeps triggering E-Stop during the clamp phase, but the operator panel shows no button pressed and all guards are closed. Diagnose the fault from PLC diagnostics and wiring data.
200 XP
📋 Scenario
Production has stopped 4 times in 2 hours — always during clamp descent between 60% and 80% of stroke. The E-Stop circuit is dual-channel (IEC 62061 SIL 2). Channel A reads open intermittently. Channel B stays healthy. The press is 7 years old. The E-Stop circuit was rewired 3 months ago after a panel upgrade.
🚨 Active Alarms
SA001 — Safety Relay CH-A Open (Category 4)
SA002 — E-Stop Loop Fault — Clamp Zone
P_FAULT_003 — Press cycle aborted at 67% stroke
📡 Sensor / I/O Status
FALSE
TRUE
TRUE
TRUE
38
310
TRUE
67%
TRUE
FALSE
FALSE
🔌 Wiring NotesE-Stop rewired 3 months ago. Cable route runs along press frame — 2.4m unsupported span from terminal block to safety relay.