SCHLEICHER SSY52 Safety Relay – Streamlined E‑stop and Guard Monitoring for Industrial Machinery

The SCHLEICHER SSY52 is a compact safety relay module designed to supervise emergency stops and safety gates in a simple, proven way. From my experience, the SSY series is typically used when you need dependable Category 0/1 stop functions with force-guided relay contacts, without adding a complex safety PLC. You might notice that it fits well in retrofit projects and new panels alike, especially where 24 VDC control circuits are standard and space is at a premium.

Typical use cases include two-channel monitoring of E‑stop buttons, safety interlock switches on access doors, and enabling circuits for drives or contactors. One thing I appreciate is the straightforward wiring and the clear front-face status LEDs—maintenance teams usually prefer that kind of transparency during commissioning and routine checks.

Order Placement Process and Guarantees

• Warranty: 365 days
• Lead time: 1 week if in stock; no more than one month at the latest
• Payment: 50% advance payment; full payment prior to delivery
• Express options: FedEx, UPS, DHL

Key Features

• Two-channel safety input – Supports dual-channel E‑stop or safety gate monitoring to achieve higher diagnostic coverage.
• Redundant safety outputs – Force‑guided relay contacts (NO) for reliable enabling of contactors and actuators.
• Auxiliary signaling contact – A normally-closed feedback contact typically used for controller diagnostics or lamp indication.
• Reset modes – Manual, monitored (edge-controlled), or automatic reset depending on wiring, which simplifies integration across machines.
• Status LEDs – Clear front indicators for power, input channels, and output states that speed up troubleshooting.
• DIN rail mounting – Compact housing for EN 60715 rails, making panel upgrades faster in most cases.
• High safety integrity – Designed to help achieve PL e per EN ISO 13849‑1 and SIL 3 architectures when correctly applied.
• Robust operating window – Suitable for typical cabinet environments in factory automation.

Technical Specifications

Brand / Model	SCHLEICHER SSY52
HS Code	8536.49 (Relays, for a voltage > 60 V or other)
Power Requirements	24 VDC (typical operating range 18–30 VDC)
Signal Inputs	2-channel safety input for E‑stop / guard switches; reset input (manual/monitored/auto, per wiring)
Outputs	Safety outputs: 2 x NO, force‑guided; Auxiliary: 1 x NC (signaling), typical
Communication Interfaces	None (local LED indication)
Installation Method	DIN rail EN 60715; screw terminals
Operating Temperature	-25 °C to +55 °C (typical for series)
Dimensions & Weight	Approx. 22.5 mm (W) x 99 mm (H) x 114 mm (D); ~180 g
Safety Ratings	Supports architectures up to PL e (EN ISO 13849‑1) / SIL 3 (IEC 61508), depending on application design

Application Fields

The SSY52 suits machinery requiring reliable stop and guard functions without full-blown safety controllers. I typically see it in:

• Packaging lines and cartoners – E‑stop strings and door interlocks for operator access
• Conveyors and material handling – Emergency pull-cord and emergency stop circuits
• Machine tools and presses – Enabling contactors and two-channel safety inputs
• Robotics cells – Perimeter fence/gate monitoring and muted zones
• Process equipment skids – Simple, auditable safety layer before drives/valves

A maintenance manager shared a nice detail: swapping in an SSY module during a downtime window took under 30 minutes because the wiring is straightforward and the terminal layout is consistent across the series.

Advantages & Value for Procurement

• Proven design – Force‑guided relay architecture with clear diagnostics reduces nuisance trips and speeds recovery.
• Compatibility – Works with standard 24 VDC control circuits and common E‑stop/guard hardware; wiring is familiar to most electricians.
• Lifecycle cost – Minimal commissioning effort and simple spares strategy; no programming tool needed.
• Audit readiness – Supports PL e / SIL 3 system designs, helping compliance teams during safety assessments.
• Scalability – Can be combined with contactor feedback loops or expansion relays if additional outputs are required.

Installation & Maintenance

• Panel environment – Install in a clean, dry control cabinet with adequate ventilation; avoid heat sources. Maintain typical spacing for natural convection.
• Mounting – Snap on DIN rail EN 60715. Ensure firm seating to avoid vibration-related loosening.
• Wiring – Use correctly rated copper conductors; torque terminals to manufacturer recommendations. Keep safety inputs and high‑noise cables separated where possible.
• Reset & feedback – Implement monitored reset and contactor feedback loops for Category 1 stop circuits when required by your risk assessment.
• Routine checks – Function-test E‑stops/guards on a defined schedule, visually verify LED states, and inspect terminals for looseness.
• Service – If used near its maximum contact load, consider periodic contactor health checks; replace relay modules according to your preventive maintenance plan.

Quality & Certifications

• CE marking; designed to align with EN ISO 13849‑1 and IEC 62061 safety principles
• UL/cUL recognition for control panels (typical for this category)
• RoHS compliant materials
• Manufacturer’s warranty: 12 months (365 days)

Helpful Accessories & Supporting Components

Depending on your machine layout, you might also consider:

• Emergency stop mushroom buttons (two-channel), with positive-opening contacts
• Safety interlock switches for doors and hatches (coded or tongue type)
• Expansion relays or contactor blocks if additional safety outputs are needed
• Control power supplies (24 VDC) with diagnostics and buffer modules for ride-through

If you’d like, share your existing wiring diagram or the stop category you’re targeting, and I can double-check whether the SSY52 fits as-is or if an expansion contact block would be smarter.