Safety Relays

Image	Part Number	Description / PDF	Quantity	Rfq
	8956.3N Altech Corporation	RM2G8 SAFETY RELAY 1 8CHANNEL 24	0
	7-1415537-1 TE Connectivity Potter & Brumfield Relays	RELAY SAFETY	0
	56.OA03.2426N Altech Corporation	OA560324V 2NO/6NC AGNI10+2UMAU I	0
	456.OA02.2424C Altech Corporation	SAFETY MODULE 4 CH 6P10A 24V 2NO	0
	56.OA02.1224S Altech Corporation	OA560212V 2NO/4NC AGNI10+5UMAU I	0
	56.OW69.2411N Altech Corporation	OW566924V 1NO/1NC AGNI10+2UMAU I	0
	56.OA69.0611C Altech Corporation	OA5669 6V 1NO/1NC AGSN02+02UMAU	0
	56.OA42.2111C Altech Corporation	OA5642 21VDC1NO/1NC CONTACTS AGS	0
	G7SA-3A1B DC110 Omron Automation & Safety Services	RELAY SAFETY 4PST 6A 110V	0
	56.OA03.1271C Altech Corporation	OA560312V 7NO/1NC AGSN02+02UMAU	0
	56.OW69.1211S Altech Corporation	OW566912V 1NO/1NC AGNI10+5UMAU I	0
	256.OA11.2431C Altech Corporation	2 CHANNEL MODULE 4P8A 24V 3NO/1N	0
	156.OA12.2424C Altech Corporation	RELAY SAFETY 6PST 8A 24V	0
	2904956 Phoenix Contact	PSR-MS50-1NO-1DO-24DC-SC	0
	56.OA69.1200N Altech Corporation	OA566912V 2CO AGNI10+2UMAU IP40	0
	56.OA44.1222C Altech Corporation	OA5644 12VDC2NO/2NC CONTACTS AGS	0
	56.OW70.2431S Altech Corporation	OW5670 24VDC3NO/1NC CONTACTS AGN	0
	ISS-105-ISO Wickmann / Littelfuse	5-CH INTRINSICALLY-SAFE ONLY	0
	56.OA03.0644C Altech Corporation	OA5603 6V 4NO/4NC AGSN02+02UMAU	0
	56.OA03.0626N Altech Corporation	OA5603 6V 2NO/6NC AGNI10+2UMAU I	0

Safety Relays

1. Overview

Safety relays are specialized control devices designed to ensure fail-safe operation in industrial systems. They monitor safety-related inputs (e.g., emergency stops, light curtains) and trigger protective actions by cutting power to machinery. Compliant with international standards like IEC 61508 and ISO 13849-1, these relays form the backbone of safety instrumented systems (SIS) across automation sectors.

2. Major Types and Functional Classification

Type	Functional Characteristics	Application Examples
Electromagnetic Safety Relays	Mechanical contact-based design with physical separation	Machinery emergency stops, simple safety circuits
Solid-State Safety Relays	Zero-contact semiconductor switching with vibration resistance	Precision equipment, explosive atmosphere environments
Programmable Safety Relays	Configurable logic with diagnostic capabilities	Robotic cells, complex safety interlocking systems
Monitoring Safety Relays	Continuous circuit integrity verification	Safety door interlocks, two-hand control systems

3. Structure and Components

Typical safety relay construction includes:

Enclosure: Flame-retardant polymer housing (UL94 V-0 rated)
Coil System: 24V DC/AC operating with bifilar winding for failure detection
Contact Arrangement: Gold-plated contacts with positive-guided mechanism
Diagnostic Circuitry: Built-in semiconductor for contact state monitoring
Mounting Options: DIN rail or PCB mount with screw/clamp terminal connections

4. Key Technical Parameters

Parameter	Typical Value	Importance
Safety Integrity Level (SIL)	SIL 3 (IEC 61508)	Determines risk reduction factor
Response Time	5-50 ms	Affects machine safe stop performance
Contact Rating	6A @ 250V AC	Dictates load switching capability
MTBF	500,000 hours	System uptime prediction
Environmental Temp	-20 C to +55 C	Operational reliability factor

5. Application Areas

Primary industries include:

Industrial Automation: CNC machines, assembly lines
Energy Systems: Wind turbine safety circuits
Transportation: Rail vehicle door control systems
Medical Equipment: MRI machine emergency cutoffs

Case Study: Automotive Press Line Safety

A major automotive manufacturer implemented safety relays in 1200-ton press machines, achieving PLc (EN ISO 13849-1) compliance through dual-channel emergency stop circuits with 35ms response time.

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
Siemens	3SK1 Safety Relay	Modular design, PROFINET integration
Schneider Electric	XPSM Safety Relay	Multi-sensor monitoring, SIL3 capable
Omron	G9SP-N Safety Controller	Programmable with 30 pre-defined safety functions
Phoenix Contact	PSR-SCP-24DC-PO Safety Relay	Plug-in module with status visualization

7. Selection Guidelines

Critical selection factors:

Safety Category: Match to application risk assessment (Cat. 2/3/4)
Environmental Conditions: Consider temperature, vibration, and EMC
Certifications: Required standards (CE, UL, T V)
Expansion Capability: Future system scalability
Diagnostic Coverage: Minimum 90% recommended

8. Industry Trends

Emerging developments include:

Integration with Industry 4.0 through IO-Link interfaces
Functional safety for collaborative robots (cobots)
Wireless safety communication protocols
Miniaturization while maintaining IP67 ratings
AI-enhanced predictive maintenance capabilities