Schneider Preventa Safety Relay XPSAXE5120P

This model belongs to Schneider-Electric Telemecanique, NOT Rockwell-AB. Many suppliers mislabel its brand.

Ciclo di vita del prodotto: Discontinued on 2023-07-31; end-of-service on 2025-12-31, no original-factory supply available.

Scomposizione del codice modello

Nucleo elettrico & Specifiche di sicurezza

Principio di funzionamento

Designed for dual-channel E-stop and safety-gate switch monitoring:

1. S11-S12 and S21-S22 terminals connect to normally-closed contacts of E-stop / safety-gate switches for dual-channel redundancy detection.
2. S33-S34 reset terminals: configurable for manual reset (with push-button) or auto-reset (cortocircuito).
3. Mismatched status between two input channels triggers fault detection; outputs latch OFF and power-cycle reset is mandatory.
4. Three safety normally-open outputs cut off hazardous circuits; one relay output provides diagnostic feedback to PLC

Main Terminal Definition

OEM-Recommended Replacement Model

Direct upgrade for XPSAXE5120P: XPSBAC1411P (Harmony XPSBAC series, 24VCA/CC, terminali a vite. Full compatibility in functions and safety ratings; nearly identical terminal layout for direct DIN-rail replacement).

⚠️Replacement Notes:

1. Verify reset logic; reset wiring logic remains identical between old and new models.
2. Output contact ratings are unchanged; no modification to external contactors is required.
3. XPSAXE5120P is legacy Preventa hardware; XPSBAC is new-generation hardware with slightly different LED indicator layout.

Application Scenarios of XPSAXE5120P

This dual-channel safety monitoring module achieves PL e / Cat.4 and SIL3. It features dual-channel E-stop & safety-gate monitoring, manuale / auto-reset options, 3 safety relay outputs plus 1 feedback output. It is deployed for machinery safety-loop cut-off and shall be installed inside control cabinets only (IP20).

✅Qualified Application Scenarios

1. Machine-Tool Industry

Torni CNC & centri di lavoro: dual-channel E-stop push-button monitoring, emergency-stop safety loops; safety-gate closure detection for machine-tool protective doors, power-circuit cut-off upon door opening.

Grinding & fresatrici: Cut-off for main-contactor and servo power loops; Y74-Y84 feedback signals sent to PLC for fault alarming.

2. Confezione & Automazione della logistica

Macchine per l'imballaggio, sigillanti di casse, palletizers and conveyor lines: monitoring for safety guard doors & perimeter safety gates; E-stop loops for equipment.

Assembly-line workstations: motore & pneumatic power cut-off when guard doors open to prevent personnel hazards.

3. Gomma & Plastics Processing Equipment

Injection-molding & extrusion machines: mold safety-gate and equipment E-stop monitoring.

Nota: This safety relay implements only logic cut-off. Safety contactors must be deployed downstream for high-current loads; direct driving of high-power motors is prohibited.

4. General-purpose Automated Production Lines & Robot-cell Perimeter Safety

Perimeter safety-gates and external E-stops for robot workcells.

Nota: Not a safety-light-curtain controller. It only processes contact-type devices (E-stop, safety switches) and cannot directly accept PNP/NPN OSSD signals from safety light curtains.

5. Tifosi, Special-purpose Test Benches

E-stop and safety-gate monitoring for test benches. Complies with CE Machinery Safety standard EN ISO 13849 for export-oriented equipment certification.

📋Wiring Guidelines for Application

1. S11-S12 / S21-S22: connect dual-channel normally-closed E-stop / safety-gate switches. Single-channel wiring downgrades safety rating; Cat.4 / PL-e compliance cannot be achieved.
2. S33-S34: reset terminals. Manual reset with push-button; auto-reset by short-circuiting S33-S34.
3. 13-14/23-24/33-34: three safety normally-open outputs, wired in series with contactor-coil loops for hazardous-energy cut-off.
4. Y74-Y84: feedback output wired to PLC for HMI alarming and fault logging.

❌Disqualified Scenarios (Insidie ​​della selezione)

1. Cannot directly interface with safety light curtains (no OSSD input; select XPS-AC series dedicated light-curtain modules).
2. ❌Not for high-frequency switching: this safety relay is a protective device actuated only during emergency / fault conditions, not for frequent load switching.
3. ❌No direct driving of high-power motors; massimo. contact rating 1.5A@24VDC. Safety contactors shall be connected downstream for heavy loads.
4. ❌Cabinet-mount only (IP20). Forbidden for environments with condensation, polvere pesante o gas corrosivo.
5. ❌Not suitable for explosive-hazardous locations.

Replacement-model Application Notes

XPSAXE5120P is obsolete. Replacement XPSBAC1411P shares identical applicable scenarios. No process-logic modification is required; only terminal wiring verification is needed.

Operating Principle of XPSAXE5120P

This is a dual-channel safety-monitoring safety relay, designed to satisfy ISO13849-1 Cat.4 / PL-e and SIL CL3. It monitors dual-channel normally-closed contact-based devices (Pulsanti di arresto di emergenza, safety-gate switches). Safety cut-off is implemented via dual-channel comparison verification, fault latching and reset logic.

1. Internal Hardware Logic
2. Power-supply loop: A1/A2 receives 24V AC/DC supply for module power-on self-test.
3. Two fully independent safety input channels S11-S12 (Channel 1) and S21-S22 (Channel 2), physically isolated for dual-channel redundancy.
4. Internal dual-channel detection circuit continuously compares status of the two input contacts.
5. Safety-output relays: 3 groups of safety normally-open contacts (13-14, 23-24, 33-34) for hazardous-circuit cut-off.
6. Auxiliary feedback relay Y74-Y84 transmits module status signals to PLC.
7. Reset loop S33-S34: handles reset logic; outputs latch OFF upon fault until valid reset is performed.

⚠️Critical feature: internal fault-latching mechanism. Once hazardous status or channel mismatch is detected, safety outputs stay permanently OFF and will not auto-recover.

2. Normal Operating Sequence
3. Power-on: A1/A2 energized, module executes self-diagnosis.
4. Safe condition (no safety-device actuation)

E-stop released / safety-gate closed: both S11-S12 and S21-S22 input channels are conducting (normally-closed contacts closed).

Identical dual-channel status confirms safe condition.

✅Internal safety relays pull-in; contatti 13-14, 23-24, 33-34 close to energize downstream contactor coils. Y74-Y84 auxiliary output closes to inform PLC of safe-ready status.

3. E-stop triggered / safety-gate opened

E-stop pressed or safety-gate opened, both input channels open simultaneously.

The module detects safety-signal loss and immediately opens all three safety outputs, de-energizing downstream contactor-coil loops and stopping machine power.

Y74-Y84 feedback toggles accordingly; PLC receives fault signal and HMI triggers E-stop / gate-open alarm.

✔Module enters latched-fault state. Outputs will NOT auto-recover even after releasing E-stop or closing safety-gate.

4. Operazione di ripristino

Ripristino manuale: push-button wired to S33-S34. After E-stop reset and gate closure, press reset push-button to release latch and restore safety outputs for machine enable.

Auto-reset: short-circuit S33-S34. Safety outputs unlock automatically once safe conditions are restored.

Safety-code recommendation: manual reset is strongly preferred for E-stop loops. Auto-reset carries unexpected-start risk.

3. Dual-channel Fault-Detection Principle (Core Safety Mechanism)

This is the key to achieving Cat.4 / PL-e.

When two input channels report inconsistent status (per esempio. one contact of dual-channel E-stop sticks closed while the other opens), the module identifies external / internal fault.

All safety outputs open and latch permanently. Outputs cannot recover merely by restoring external-switch contacts.

A full power-cycle (disconnect A1/A2 supply) is required to clear the latch. Troubleshoot and replace defective E-stop / safety-gate switches before power-on and reset.

This logic detects contact welding and wire-break faults to prevent safety-function loss caused by single-component failure.

4. Output-loop Logic
5. Three safety outputs (13-14/23-24/33-34): safety-relay contacts

Wired in series with safety-contactor-coil loops as safety-cut-off paths. Not for direct high-power-load driving. Massimo. valutazione dei contatti:1.5A @24VDC. All three contacts act synchronously internally.

2. Y74-Y84 signal-feedback output

Auxiliary diagnostic relay, NOT a safety-related output. Used only for PLC status acquisition and fault alarming; must not be used for machine safety cut-off.

5. Typical Fault-response Behaviours
6. Single-channel wire-break or single-contact welding → channel mismatch → outputs open & latch; power-cycle troubleshooting required.
7. Reset-loop open-circuit → reset denied; machine cannot start.
8. Supply-voltage out-of-range → safety outputs force-open.
9. Critical Boundary Constraints
10. Only normally-closed dual-channel devices are acceptable. Safety-light-curtain OSSD signals cannot be connected directly.
11. Single-channel input disables dual-channel verification, downgrading safety rating to Cat.2 (PL-e cannot be achieved).
12. Safety-output contacts shall not be paralleled for current expansion. Add safety contactors downstream for heavy-load scenarios。