What causes fault code SAFE-ESTOP1 (Emergency Stop Circuit — Station Unknown)?

An E-stop was pressed at a remote station — operator cannot identify which one. An E-stop button is mechanically stuck in the pressed position — spring or latch failure. E-stop wiring has a broken wire — circuit reads as open (same as pressed), fail-safe behavior. E-stop contact block failed open — contact does not close when button is released. Series-wired E-stop circuit makes individual station identification difficult

How do I fix fault code SAFE-ESTOP1?

Walk to every E-stop station on the machine and check each button — look for buttons in the pressed (down/locked) position. At each station, twist the E-stop mushroom head to release — if it pops up, that station was pressed. If all E-stops appear released but circuit is still open, use a multimeter to trace the circuit station by station. Check each E-stop for mechanical damage — buttons that won't pop up need replacement. On series-wired circuits, disconnect each station one at a time and jumper across to isolate the faulted station. After finding and clearing the E-stop, press the safety reset button to re-enable the machine

Emergency Stop Circuit — Station Unknown

SAFE-ESTOP1

Emergency stop circuit is open but the specific station that was pressed cannot be identified from the control system. One or more E-stop buttons are engaged somewhere in the circuit.

medium general conveyor packaging palletizer

safety e-stop emergency stop circuit station series

Probable Causes (ranked)

An E-stop was pressed at a remote station — operator cannot identify which one
An E-stop button is mechanically stuck in the pressed position — spring or latch failure
E-stop wiring has a broken wire — circuit reads as open (same as pressed), fail-safe behavior
E-stop contact block failed open — contact does not close when button is released
Series-wired E-stop circuit makes individual station identification difficult

Fix Steps

1 Walk to every E-stop station on the machine and check each button — look for buttons in the pressed (down/locked) position
2 At each station, twist the E-stop mushroom head to release — if it pops up, that station was pressed
3 If all E-stops appear released but circuit is still open, use a multimeter to trace the circuit station by station
4 Check each E-stop for mechanical damage — buttons that won't pop up need replacement
5 On series-wired circuits, disconnect each station one at a time and jumper across to isolate the faulted station
6 After finding and clearing the E-stop, press the safety reset button to re-enable the machine

Field Trick

For machines with 10+ E-stop stations in series, put numbered labels on every E-stop and add individual E-stop status inputs to the PLC. Yes, it takes more wiring and I/O points, but being able to see on the HMI 'E-Stop Station 7 Active' saves 30 minutes of walking the machine every time someone bumps a button. Install it once, save time forever.

Suggested Replacement Parts

Parts matched to fault category: E Stop

Allen-Bradley Guardmaster 440R-N23126 P/N: 440R-N23126 Dual-channel safety relay, 24VDC, 3 N.O. + 1 N.C., Cat 4 / PLe

AutomationDirect $125.00 Amazon $95.00 Grainger $155.00

Pilz PNOZ X3 Safety Relay P/N: 774310 24VDC/AC, 3 N.O. + 1 N.C., E-stop and safety gate monitoring

AutomationDirect $145.00 Amazon $135.00 McMaster-Carr $165.00

Prices are estimates. Verify part numbers match your equipment before ordering.

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