Pilz 772100 Pilz Safety Relay

Basic Model Information

Part No.: 772100

Product Name: PNOZ X2 24VAC Safety Relay

Brand: PILZ (German safety automation brand)

2. Core Electrical Specifications
3. Supply Voltage: 24 V AC
4. Safety Contacts: 2 normally open (NO) safety output contacts
5. Auxiliary Contacts: None
6. Safety Classification

EN ISO 13849-1: Cat. 4 / PL e

IEC 61508: SIL 3

5. Input Circuit: Single-channel E-stop / safety gate input with spring terminal wiring
6. Contact Ratings

Resistive Load: 230V / 6A

Minimum Switching Current: 1mA / 5V DC

3. Functional Description

Standard basic safety relay compatible with E-stop buttons, safety gate switches and safety mats

Auto-reset mode (no reset button; outputs close automatically after power recovery)

Compact module for DIN rail mounting (35mm standard rail)

Housing width: 22.5mm

4. Environmental & Mechanical Parameters

Operating Temperature: 0 ~ +55 ℃

Storage Temperature: -20 ~ +70 ℃

Protection Class: IP20 (for cabinet installation only)

Certifications: CE, UL, CSA

5. Typical Replacement Models
6. Equivalent DC version: 772101 (PNOZ X2 24VDC)
7. Manual reset version: 772130 (PNOZ X2.1 24VAC)
8. Wider multi-contact version: PNOZ X3 / X4 series

PILZ 772100 (PNOZ X2 24VAC) Complete Terminal, Wiring, Dimension & Troubleshooting Manual

1. Basic Model Information

Order No.: 772100

Model: PNOZ X2 24VAC

Supply: 24V AC

Reset Mode: Auto-reset (no external start terminals; outputs close upon power restoration)

Safety Contacts: 2 force-guided normally open contacts 13-14 / 23-24

Safety Level: Cat.4 / PL e / SIL3

2. Complete Terminal Definition (Top to Bottom)

2.1 Power Terminals (Left Supply Area)

A1: 24V AC Live (L)

A2: 24V AC Neutral (N)

> Supply range: 20.4～26.4V AC; a 1A slow-blow fuse is recommended upstream

2.2 Safety Input Monitoring Terminals (Middle Input Circuit)

S11: Common input terminal (24V AC incoming line)

S12: Channel 1 input (one end of E-stop/safety gate NC contact)

S22: Channel 2 input (second redundant channel for dual-circuit design)

> This model has no S21 and no Y1/Y2 start terminals, purely auto-reset design

2.3 Safety Output Contacts (Right Load Circuit)

1. 13-14: 1st set of force-guided safety NO contacts
2. 23-24: 2nd set of force-guided safety NO contacts

No auxiliary contacts or feedback circuit terminals

3. Two Standard Wiring Schemes (Field Commonly Used)

Scheme 1: Single-channel Wiring (Only meets PL d, for simple low-risk machines)

Application: Low-risk equipment with single E-stop only

1. Connect S11 to 24V AC L
2. Short-circuit S12 and S22 together
3. Wire E-stop NC contacts in series to the short joint, then route back to A2 (N)

Principle: Two input lines shorted; internal single-channel monitoring only, unable to detect short circuits between contacts

Scheme 2: Dual-channel Redundant Wiring (Mandatory Cat.4/PL e for Machine Tools & Automation Lines)

Application: Injection molding, stamping, robotics, production line safety gates

1. S11 = 24V AC L
2. S12: 1st NC contact of E-stop
3. S22: 2nd NC contact of E-stop
4. Parallel the other ends of both contacts and connect to A2 (N)

Advantages: Detects input earth short circuits, inter-cable short circuits and single contact welding

Standard Output Wiring

Wire contactor coils and main circuit control power in series with 13-14 + 23-24 in series (dual safety cut-off)

Resistive load: 230V/6A

Inductive contactor load: Install RC surge suppressor in parallel with coil

Fit a 6A fuse upstream of outputs to prevent contact welding

4. Mounting Dimensions & Wiring Specifications

Overall Mechanical Dimensions (mm)

Width × Height × Depth: 22.5 × 87 × 121

Mounting: Snap-on installation on 35mm standard DIN rail

Weight: Approx. 190g

Protection: IP20, cabinet use only

Terminal Wiring Requirements

Screw terminal torque: 0.6 N·m

Wire stripping length: 7mm

Cable cross-section: Solid wire 0.2～4mm²; stranded wire with ferrule 0.2～2.5mm²

Max total length of input circuit cables: ≤300m (line resistance ≤30Ω limit for AC models)

5. Front Panel Indicator Meanings
6. Green POWER LED: Power supply normal
7. Green CH1 / CH2 LEDs: Corresponding input channel circuit closed (safe state)

Indicator Status Reference Table

6. Troubleshooting Matrix (Phenomenon → Root Cause → Resolution Steps)

Fault 1: POWER LED fails to light up after power-on

1. No 24VAC measured at A1-A2: Check upstream circuit breaker, fuse and transformer supply
2. Normal voltage at A1/A2 but LED remains off: Internal power supply damaged; replace 772100 directly
3. Terminal short circuit: Cut power, rework wiring and eliminate cable insulation earth leakage

Fault 2: Power supply normal, CH LEDs off, safety outputs de-energized

1. E-stop NC contact open: Reset E-stop button
2. Broken input cable: Measure continuity between S11-S12/S22 section by section
3. Input cable earth short: Disconnect cables and locate grounding fault segment by segment
4. Single contact failure under dual-channel wiring: Replace dual-circuit E-stop switch

Fault 3: All LEDs illuminated but machine fails to start (no output at 13-14/23-24)

1. Blown output circuit fuse: Replace fuse and check for shorted contactor coil
2. Welded safety contacts: Irreparable module damage; install new unit
3. Load current exceeding 6A: Add intermediate relay to expand output capacity

Fault 4: Random tripping and CH LED extinction during operation (intermittent fault)

1. Excessively long cables with excessive line resistance: Use thicker cables or shorten wiring routes
2. Interference from power cables routed alongside safety wiring: Separate cable runs with ≥20cm clearance
3. High contact resistance caused by oxidized contacts: Replace E-stop / safety gate switch
4. Strict Forbidden Operations (Violation leads to lost safety certification or burnt module)
5. Never connect 220V mains to A1/A2; only 24V AC is permitted
6. Never omit the second contact in dual-channel wiring (Cat.4 compliance cannot be achieved)
7. Never feed an independent external power source to input circuits; input power must share the same 24VAC supply as module A1/A2
8. Do not parallel output contacts for capacity expansion; series connection only. Use external safety contactors for load expansion
9. Never drive high-power inductive loads without fuses; high risk of contact welding
10. Do not plug/unplug input cables while the module is live; electric arcs will damage internal monitoring circuitry
11. Equivalent Series Replacement Reference
12. DC alternative: 772101 (PNOZ X2 24VDC, identical terminal layout, 24V DC supply only)
13. Manual reset model: 772130 (PNOZ X2.1 24VAC, added Y1/Y2 start terminals requiring external reset button)
14. Multi-contact upgrade: 774300 PNOZ X3 (3 safety contacts, 45mm width)
15. Complete Part Number List for PILZ PNOZ X2 Series (22.5mm width, 2 NO safety contacts, Cat.4/PL e/SIL3)

Benchmark Reference: 772100 = PNOZ X2 24VAC auto-reset, no manual start terminals

1.1 Pure Auto-reset Models (No Y1/Y2 reset terminals, direct equivalent to 772100)

1.2 Manual Controlled Reset Models (X2.1 series with external Y1/Y2 reset button)

1.3 45mm Wide X2C Series with Feedback Circuits (Controlled start, equipment feedback monitoring)

777303 PNOZ X2P C 24VACDC: Spring terminals with equipment feedback monitoring

774303 PNOZ X2 24VACDC: Universal AC/DC base model

1.4 Distinction Notes (Avoid Selection Mistakes)

1. 772100 ≠ PNOZ m B0: PNOZ m B0 (marked 772100) is a modular safety controller, completely different product category from PNOZ X2 safety relay. Same part number but unrelated products. All replacements below apply exclusively to PNOZ X2 24VAC safety relay 772100.
2. Model 772100 X2 only: 22.5mm width, 2 NO safety contacts, no auxiliary contacts, pure auto-reset.
3. Cross-brand Equivalent Replacement Table (Matching 772100: 24VAC, dual-channel, 2 safety NO contacts, auto-reset, Cat.4 PL e SIL3)

2.1 Schneider Preventa XPS Series

2.2 ABB Safety Safety Relays

2.3 OMRON G9SE Series (Most Widely Used Drop-in Equivalent)

2.4 Phoenix Contact PSR Series

2.5 IFM Safety Relays

2.6 Domestic Certified Equivalents (Cat.4/PL e/TÜV Certified)

3. Replacement Selection Criteria (Must Verify Before Swap)

3.1 Mandatory Identical Parameters (Otherwise Direct Wiring Impossible)

1. Rated supply voltage: 772100 fixed at 24V AC. DC24V models cannot be directly replaced unless an AC/DC power converter is added.
2. Reset logic: Original equipment uses auto-reset. Do not select forced manual reset models (X2.1, XPS-AC3710, etc.)
3. Number of safety contacts: 2 sets of force-guided NO contacts (13-14 / 23-24). Avoid models with 3NO + 1NC auxiliary contacts.

3.2 Minor Compatible Differences (No Program Modification Required, Minor Wiring Adjustment Only)

1. Terminal pitch / terminal type: Screw vs spring terminals only require different crimping tools
2. Indicator layout: No impact on safety functions
3. Maximum cable length limit: Difference ≤50m among all 22.5mm compact modules, negligible for field wiring
4. Modification Precautions for Replacement
5. Optimal zero-modification replacement: OMRON G9SE-201 AC24. Near identical terminal definition, dimensions, safety level and auto-reset logic as 772100; electricians can reuse existing wiring without changes.
6. Schneider XPS-AC3110 mapping: Input terminals S11/S12/S22 correspond to XPS IN1/COM/IN2; output contact series wiring method is fully identical.
7. Mixed model prohibition: Replacing auto-reset unit with manual reset model will prevent automatic machine startup after power-on; external reset button must be installed additionally.
8. Safety certification retention: All listed models comply with EN ISO 13849 Cat.4 PL e and IEC 61508 SIL3. Machine overall safety certification remains valid after replacement.
9. Load protection: 6A fuse must still be fitted on outputs post replacement; RC snubber circuit mandatory for inductive contactor coils.
10. Quick Selection Recommendations
11. Imported zero-wiring-modification replacement: G9SE-201 AC24 (OMRON)
12. Matching Schneider system equipment: XPS-AC3110
13. Phoenix Contact cabinet integrated solution: PSR-SCP-24AC/ESA2/2X1
14. Cost-effective domestic alternative: SRS2-24AC (Covestro)
15. Replacement for original DC model 772101: G9SE-201 DC24 / XPS-AC5110