For cross-brand replacement of model 751104, the core differences lie in system integration compatibility, diagnostic functions, wiring methods and price ranges. Siemens is ideal for full Siemens-based systems; Schneider boasts powerful diagnostic functions; Omron features the most compact size; Phoenix Contact offers high cost performance; Weidmüller provides flexible wiring; Eaton delivers superior environmental adaptability; Wieland shares identical dimensions with Pilz products.
Fungo 751104 PNOZ s4 Compact Safety Relay
- Informazioni di base & Precise Model Definition
Ordine n.: 751104
Modello ufficiale: PNOZ s4 C 24VDC
Serie: PNOZsigma s Compact Safety Relay
Official Manual: 21396-EN-21 (2026 Versione)
Ripartizione del modello
| Segmento | Senso | Descrizione |
| PNOZ | Core series code of Pilz safety relays | Safety control products complying with EN ISO 13849-1 |
| S | Ultra-slim compact design | Housing width: only 22.5mm, risparmiare spazio nell'armadio |
| 4 | Contact configuration code | Standard: 3 Normalmente aperto (NO) + 1 Normalmente chiuso (NC) safety contacts |
| C | Terminal type | Cage spring terminals (screwless); old model 750104 adopts screw terminals |
| 24VCC | Tensione operativa nominale | CC 24 V, voltage range: 20.4-26.4V (-15%/+10%) |
- Core Electrical Specifications (Official Authorized Data)
| Categoria | Specifica | Osservazioni |
| Power Supply Parameters | ||
| Tensione operativa nominale | CC 24 V | Fluctuation range: 20.4~26.4V |
| Power Consumption Current | ≤120mA | No-load condition |
| Corrente di spunto | 0.2UN | Pulse duration: 15SM |
| Caratteristiche di ingresso | ||
| Input Channels | Dual-channel safety input (S11-S12; S21-S22) | Supports single/dual-channel wiring with inter-contact short-circuit detection |
| Corrente in ingresso | 50mA per channel | At 24VDC |
| Reset Mode | Manuale / Automatic optional | Automatic reset enabled by short-circuiting S34-S12 |
| Caratteristiche di uscita | ||
| Safety Outputs | 3 NO contacts: 13-14, 23-24, 33-34 | Each group consists of 2 series-connected NO contacts for higher safety |
| Auxiliary Output | 1 NC contact: 41-42 | For fault indication and alarm signal |
| Rated Contact Current | 6UN (AC-1/DC-1) | Resistive load at 240VAC / 24VCC |
| Thermal Rated Current | 4.5UN | Quando 3 contacts operate simultaneously |
| Meccanico & Parametri Ambientali | ||
| Tempo di risposta | ≤15ms | Key safety-related index |
| Larghezza alloggiamento | 22.5mm | Standard DIN rail mounting size |
| Classe di protezione | IP20 | For cabinet internal installation |
| Temperatura operativa | -10℃ ~ +55 ℃ | Temperatura di conservazione: -25℃ ~ +70 ℃ |
| Tipo di cablaggio | Cage spring clamp terminal | Wire cross-section: 0.2~2,5 mm² |
| Safety Certifications | ||
| Safety Level | NELL'ISO 13849-1: PL e, Cat.4 | Highest safety rating |
| Functional Safety | CEI 61508: SIL3 | Applicable to safety-critical systems |
| Certificazioni Internazionali | CE, TÜV, UL, CSA | Globally approved |
- Full PNOZ s Series Order Number List (Modelli tradizionali)
| Ordine n. | Modello | Voltaggio | Configurazione dei contatti | Tipo di terminale | Caratteristiche principali |
| 751101 | PNOZ s1 C | 24VCC | 1NA+1NC | Morsetto a molla | Single-channel input, basic safety control |
| 751102 | PNOZ s2 C | 24VCC | 3NA+1NC | Morsetto a molla | Single-channel input, no short-circuit detection |
| 751103 | PNOZ s3 C | 24VCC | 3NA+1NC | Morsetto a molla | Dual-channel input, manual reset |
| 751104 | PNOZ s4 C | 24VCC | 3NA+1NC | Morsetto a molla | Dual-channel input, manual/automatic reset optional (mainstream model) |
| 751105 | PNOZ s5 C | 24VCC | 4NO (2 instant + 2 delayed) | Morsetto a molla | Delayed output, for equipment requiring braking delay |
| 751106 | PNOZ s6 C | 24VCC | 3NO+1NC+1 semiconductor output | Morsetto a molla | Uscita a stato solido, suitable for high-speed switching |
| 750104 | PNOZ s4 | 24VCC | 3NA+1NC | Terminale a vite | Obsolete model, replaced by 751104 |
| 751204 | PNOZ s4 C 24VDC | 24VCC | 3NA+1NC | Morsetto a molla | High-current upgraded version, rated contact current 10A |
- Sostituzione & Compatibility List
4.1 Old & Sostituzione del nuovo modello
| Old Model | Modello sostitutivo | Descrizione della sostituzione |
| 750104 | 751104 | Pienamente compatibile; only terminal changed from screw to spring clamp, funzioni identiche & parametri |
| 750134 | 751104 | Replacement for wide voltage version (24-240V CA/CC); confirm power supply type first |
4.2 Competitor Equivalent Reference (Same-grade Safety Relays)
| Marca | Modello | Vantaggi comparativi |
| Siemens | 3TK2825-1BB40 | prezzo più basso, perfect for Siemens PLC system integration |
| Schneider | XPS-AV1110 | More comprehensive diagnostic functions, fit for complex safety systems |
| Omron | G9SA-321-T075 | More compact size, ideal for ultra-narrow installation space |
| PILZ 751104 | — | Elevato livello di sicurezza (PL e/SIL3), cablaggio flessibile, complete global certifications |
- Scenari applicativi & Industry Cases
✅ Recommended Application Scenarios
- Emergency Stop Circuit: Connect series emergency stop buttons to cut off power of hazardous equipment instantly once triggered
- Safety Gate Monitoring: Detect open/closed status of protective gates and halt moving machine parts when gates open
- Photoelectric Safety Protection: Connect safety light curtains to stop equipment when personnel enter dangerous zones
- Two-hand Control: Applied to punching & bending machines; machine starts only with simultaneous two-hand operation to avoid misoperation
- Automated Production Line: Multi-device linkage safety control for zoned emergency stop
- Confezione / Stampa / Injection Molding Machinery: Mold protection and safety interlock control
Typical Industry Applications
Produzione automobilistica: Safety fence monitoring for welding robots
Electronic Assembly: Safety gate interlock for SMT production lines
Food Processing: Emergency stop circuit for filling machines complying with food machinery safety standards
Attrezzature per macchine utensili: Safety guard control for CNC machine tools
❌ Not Recommended Scenarios
Direct AC220V power supply (convert to 24VDC via transformer)
Outdoor open-air, high humidity (>95%RH) and heavy dust environments (only IP20 protection)
Direct switching of high-power main circuits (max 6A contact current; expand via contactors)
Aree a prova di esplosione (senza certificazione antideflagrante)
Underwater installation or high-pressure washing environments
- Conformità del trasporto aereo & Certification Info
6.1 Air Freight Compliance Confirmation
No built-in batteries or energy storage components: Classified as ordinary industrial electrical goods, non-dangerous goods
Air freight category: General cargo, no special shipping documents or marks required
Sea & land transportation: No restrictions, shipped as standard industrial products
6.2 Principali certificazioni & Official Numbers
| Certificazione | Certificato n. | Applied Standard |
| CE | 0120-CPD-022 | IN 60947-5-1, NELL'ISO 13849-1 |
| TÜV | 9706037 | CEI 61508: SIL3 |
| UL | E175588 | UL 508, UL 61010-1 |
| CSA | LR24536 | CSA C22.2 No. 14 |
- Risoluzione dei problemi & Linee guida per la manutenzione
Difetti comuni & Soluzioni
| Fenomeno di guasto | Possibile causa | Inspection Steps | Soluzioni |
| Power LED flashes | Low/unstable input voltage | 1. Measure voltage between terminal A1-A2 | 1. Adjust voltage to 20.4-26.4V |
| 2. Check power adapter | 2. Replace qualified power supply | ||
| Fault LED keeps on | Short circuit or failure on input channels | 1. Check wiring of S11-S12 / S21-S22 | 1. Eliminate inter-contact short circuit |
| 2. Test after disconnecting loads | 2. Replace damaged input components | ||
| In1/In2 LED flash alternately | Short circuit between S12 and S22 | 1. Check dual-channel wiring | 1. Correct wrong wiring |
| 2. Power off and restart | 2. Ensure channel insulation | ||
| No output signal | 1. Input not activated | 1. Check input status | 1. Activate input signals |
| 2. Reset circuit open | 2. Verify S34-S12 reset loop | 2. Close reset circuit | |
| 3. Damaged output contacts | 3. Measure contact resistance | 3. Replace the relay | |
| Accidental emergency stop | 1. Cablaggio allentato | 1. Tighten all terminals | 1. Stringere nuovamente i terminali |
| 2. Electromagnetic interference | 2. Add shielding measures | 2. Use shielded cables | |
| 3. Power fluctuation | 3. Install filter modules | 3. Stabilize power quality |
Programma di manutenzione
Ispezione di routine: Check LED status and wiring tightness monthly
Manutenzione periodica: Clean terminals and inspect contact wear every 6 mesi
Service life suggestion: Replace every 8~10 years (adjust according to operating frequency)
- Selection Mnemonic
24V S4 model with 3NO+1NC spring terminals,
Dual-channel input with dual reset modes,
PL e & SIL3 high safety performance,
22.5mm slim size saves cabinet space,
Standard safety choice for industrial control!
Overview of Cross-brand Replacement for Pilz 751104 PNOZ s4 Compact Safety Relay
For cross-brand replacement of model 751104, the core differences lie in system integration compatibility, diagnostic functions, wiring methods and price ranges. Siemens fits full Siemens automation systems; Schneider has powerful diagnostics; Omron is ultra-compact; Phoenix Contact is cost-effective; Weidmüller supports diverse wiring; Eaton adapts well to harsh environments; Wieland is dimensionally identical to Pilz.
- Tabella comparativa dei parametri principali
| Marca | Modello | Ordine n. | Tempo di risposta | Larghezza | Vantaggi fondamentali |
| PILZ | PNOZ s4 C 24VDC | 751104 | ≤15ms | 22.5mm | Complete global certifications, cablaggio flessibile |
| SIEMENS | 3TK2825-1BB40 | 3TK2825-1BB40 | ≤15ms | 22.5mm | Strong system integration, rich diagnosis |
| SCHNEIDER | XPSUAF13AP | XPSUAF13AP | ≤15ms | 22.5mm | Espandibile, powerful diagnostic performance |
| OMRON | G9SA-321-T075 | G9SA-321-T075 | ≤15ms | 17.5mm | Ultra-slim structure |
| FENICE | PSR-SPP-24DC/ESD/3X1/1X2 | 2904950 | ≤15ms | 22.5mm | Prestazioni ad alto costo, facile installazione |
| WEIDMÜLLER | SCS 24VDC P1SIL3DS MG3 | 8938670000 | ≤15ms | 22.5mm | High protection grade, harsh environment resistant |
| EATON | MSR1270 | MSR1270 | ≤15ms | 22.5mm | Ampio intervallo di temperature, heavy industry oriented |
| WIELAND | SNO 4083-24V | SNO 4083-24V | ≤15ms | 22.5mm | Pin-to-pin replacement with Pilz |
- In-depth Brand Analysis & Replacement Suggestions
2.1 Siemens 3TK2825-1BB40
Vantaggi fondamentali
Seamless connection with Siemens S7 series PLC for shared diagnostic data
Supporta PROFIBUS / PROFINET communication
Built-in current monitoring for output contact fault diagnosis
Conforme alla norma CEI 61508 SIL3 & NELL'ISO 13849-1 PL e
Application Tips
✅ Prioritize for full Siemens automated projects to cut integration costs
✅ Perfect for complex safety systems requiring PLC data interaction
❌ Less cost-effective in non-Siemens systems
2.2 Schneider XPSUAF13AP
Vantaggi fondamentali
Multi-level fault diagnosis with LED & text fault display
Modular design expandable up to 8 safety outputs
Built-in safety self-test function simplifies on-site commissioning
Compatible with Schneider safety bus system
Application Tips
✅ Ideal for production lines requiring detailed fault troubleshooting
✅ Best choice for multi-function integrated safety equipment
✅ Matches perfectly with Schneider Modicon PLC
2.3 Omron G9SA-321-T075
Vantaggi fondamentali
Ultra-narrow 17.5mm width saves 50% spazio nell'armadio
Low power consumption ≤80mA, suitable for battery-powered devices
Built-in surge suppression with strong anti-interference capability
Economical for mass installation
Application Tips
✅ Recommended for space-limited equipment such as small robots
✅ Suitable for large-quantity layout on assembly lines
❌ Not fit for frequent manual wiring operation due to narrow terminal spacing
2.4 Phoenix Contact PSR-SPP-24DC/ESD/3X1/1X2
Vantaggi fondamentali
Spring clamp wiring triples installation efficiency
Built-in electronic short-circuit protection extends contact service life
Hot-swap supported for easy on-site maintenance
Obvious price advantage with high cost performance
Application Tips
✅ Best choice for projects demanding fast installation & facile manutenzione
✅ Matches Phoenix distributed I/O systems perfectly
✅ Cost-saving option for mass-produced standard equipment
2.5 Weidmüller SCS 24VDC P1SIL3DS MG3
Vantaggi fondamentali
Standard IP20, partial models reach IP40 protection level
Supports 0.2~4mm² wide-range wire connection
All-round self-diagnosis for power, input and output faults
Excellent vibration resistance for rail transit & heavy machinery
Application Tips
✅ Preferred for dusty & vibrating harsh working conditions
✅ Suitable for applications needing large cross-section wiring
✅ Unified wiring layout matched with Weidmüller terminal blocks
2.6 Eaton MSR1270
Vantaggi fondamentali
Wide working temperature range: -25℃~+70℃ for extreme environments
10A high rated current can directly drive small motors
Multi safety logic: arresto di emergenza, safety gate, controllo a due mani
Complete global safety certifications
Application Tips
✅ Suitable for outdoor and non-air-conditioned workshop equipment
✅ Widely used in heavy industry and new energy industries
✅ Perfect alternative for high-current safety control demands
2.7 Wieland SNO 4083-24V
Vantaggi fondamentali
Fully consistent 22.5mm dimension with Pilz PNOZ s series for direct replacement
Identical terminal layout with no cabinet modification needed
Built-in contact welding detection function
15~20% lower price than Pilz original products
Application Tips
✅ First choice for Pilz system renovation & riduzione dei costi
✅ Ideal for retrofitting projects retaining original cabinet layout
✅ Preferred alternative in mechanical manufacturing industry
- Key Factors for Cross-brand Selection
| Fattore di selezione | Punti chiave | Recommended Brands |
| Compatibilità del sistema | Matching degree with existing PLC & automation platform | Siemens (S7), Schneider (Modicon), Omron (Sysmac) |
| Space Limitation | Available installation space inside cabinet | Omron (17.5mm), Pilz/Siemens/Schneider (22.5mm) |
| Diagnostic Demand | Fault diagnosis depth | Schneider (superiore), Siemens, Weidmüller |
| Wiring Efficiency | On-site installation & maintenance convenience | Contatto della Fenice (spring terminal), Fungo 751104 |
| Ambient Condition | Temperatura, umidità, vibration level | Eaton (wide temp), Weidmüller (anti-vibration) |
| Cost Budget | Overall project cost control | Contatto della Fenice, Wieland, Omron |
| Special Safety Functions | Delay output, extended output etc. | Schneider (espandibile), Eaton (corrente elevata) |
- Replacement Implementation Rules & Note
4.1 Direct Replacement Feasibility
Physical Compatibility: All models except Omron are 22.5mm wide for direct DIN rail mounting
Electrical Compatibility: Uniform 24VDC power supply and 3NO+1NC output for direct wiring replacement
Functional Compatibility: All support dual-channel input and dual reset modes with identical safety standards
4.2 Replacement Precautions
- Reset Circuit: Automatic reset wiring definition varies by brand; adjust S34-S12 connection referring to official manuals
- Diagnostic Program: Reconfigure PLC diagnosis logic to adapt to new brand fault signal definition
- Certification Verification: Confirm alternative models meet all required project certifications (CE, UL, CSA etc.)
- Capacità di contatto: Ensure rated contact current meets actual load demand (minimum 6A consistent with 751104)
4.3 Optimal Selection Scheme
Nuovi progetti: Select the same-brand safety relay as your automation control system for better compatibility
Renovation projects: Prioritize Wieland (dimension fully compatible) or Phoenix Contact (easy wiring)
Bulk replacement: Choose cost-effective Omron or Phoenix Contact
- Cross-brand Selection Mnemonic
Siemens excels in system integration,
Schneider leads in diagnosis function,
Omron owns the slimmest dimension,
Phoenix wins high cost attribution,
Weidmüller adapts tough condition,
Eaton fits wide temperature application,
Wieland replaces Pilz without variation,
Matching selection brings best operation!
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