Honeywell SZR-LY2-N1 110VAC General Purpose Relay – SZR Series

Honeywell SZR-LY2-N1 110VAC — DPDT Octal Relay in Industrial Switching Circuits

The Honeywell SZR-LY2-N1 110VAC is a double-pole double-throw (DPDT) general purpose relay designed for sustained operation in industrial control panels, PLC output interfacing, and machine automation circuits. Operating on a 110VAC coil voltage at 50/60 Hz, it draws approximately 1.6 VA at steady state — a figure that matters when sizing transformer secondaries in dense relay panels. The 8-pin octal base format allows plug-in installation into compatible sockets, enabling field replacement without rewiring and reducing mean time to repair (MTTR) in production environments.

Within the SZR Series, Honeywell standardized the mechanical envelope and pin geometry across coil voltage variants, which means a panel designed around the SZR-LY2-N1 110VAC can be adapted to 24VDC or 220VAC coil variants by socket substitution alone — a practical advantage for OEM machine builders targeting multiple export markets. The DPDT contact arrangement provides two independent Form C switching circuits per relay body, each rated at 10A resistive at 250VAC or 10A at 30VDC. This contact rating covers the majority of industrial load types encountered in auxiliary control circuits: pilot lamps, solenoid valves, small motor starters, and signal conditioning relays.

The relay’s mechanical life rating of ≥10,000,000 operations and electrical life of ≥100,000 operations at rated load position it as a long-service component in high-cycle applications such as conveyor zone control, injection molding auxiliary circuits, and HVAC damper sequencing. Operate and release times are both specified at ≤20ms, which is adequate for the vast majority of PLC-driven switching tasks where scan-cycle latency already dominates the timing budget.

Real-time Stock & RFQ: [email protected] | WhatsApp: +86 18359268345

Technical Parameters

Hardware Logical Analysis

The SZR-LY2-N1’s coil circuit is wound on a bobbin-type former with a laminated silicon-steel core, a construction that minimizes eddy-current losses at 50/60 Hz and keeps steady-state coil temperature rise within acceptable limits even in enclosed enclosures operating at +40°C ambient. The coil impedance at 110VAC is sized to produce a pull-in force that reliably closes the armature against the return spring across the full specified voltage range — typically 70–110% of rated coil voltage for pull-in and 10–30% for drop-out, giving the relay a defined hysteresis band that prevents contact chatter under brownout conditions.

The silver-alloy (AgNi) contact material is selected for its resistance to arc erosion and its relatively low contact resistance (typically <100 mΩ initial) compared to pure silver, which is prone to sulfide film formation in industrial atmospheres. The DPDT contact bridge is mechanically linked to the armature via a push-rod mechanism, ensuring simultaneous make-before-break or break-before-make sequencing is consistent across both poles — a critical property when the relay is used for motor reversing interlocks where cross-conduction must be prevented.

The 8-pin octal base geometry provides a keyed mechanical interface that prevents incorrect socket insertion. Pin assignments follow the standard LY2 octal convention: pins 1–4 carry the contact circuits (NC, common, NO for each pole) and pins 5–8 carry the coil and auxiliary connections. This standardized pinout allows the SZR-LY2-N1 to be cross-referenced against equivalent octal relays from other manufacturers without rewiring the socket, provided the coil voltage matches. The transparent dust cover, where fitted, allows visual confirmation of armature position — a practical diagnostic feature that eliminates the need to probe the circuit to determine relay state during panel commissioning.

From an EMC standpoint, the inductive coil presents a transient suppression challenge when de-energized. The back-EMF spike generated by coil collapse can reach several hundred volts in microseconds if unsuppressed. Panel designers should fit a metal oxide varistor (MOV) or RC snubber across the coil terminals when driving from solid-state PLC outputs, particularly transistor-type output modules with low avalanche ratings. For relay-output PLC modules, the internal contact arc suppression is generally sufficient, but the recommendation holds for long coil lead runs where cable inductance adds to the transient energy.

System Integration Benefits

• Direct 110VAC Coil Drive: Eliminates the need for a 24VDC power supply rail dedicated to relay coils in North American and Asian 110VAC control systems, reducing panel BOM cost and wiring complexity.
• Deterministic Switching Latency: With operate and release times both ≤20ms, the relay’s switching behavior is predictable within a single PLC scan cycle (typically 10–50ms), enabling accurate sequence timing in ladder logic programs without additional timer compensation.
• Galvanic Isolation Between Control and Load Circuits: The coil-to-contact dielectric strength of 2,000VAC provides robust isolation between the PLC control voltage domain and the field device power domain, protecting sensitive I/O modules from load-side transients.
• DPDT Architecture for Interlocking Logic: Two independent Form C contacts per relay body allow a single relay to simultaneously open one circuit and close another — the fundamental requirement for motor reversing contactors, transfer switch logic, and safety interlock bypass circuits.
• Plug-In Octal Base for Zero-Downtime Replacement: Field technicians can swap a failed relay in under 60 seconds without tools or rewiring, a measurable reduction in MTTR compared to screw-terminal relay formats.
• Wide Ambient Temperature Tolerance (−40°C to +70°C): Covers outdoor enclosures in northern climates, cold-storage facility panels, and high-ambient machine rooms adjacent to process heat sources without derating.
• Standardized Footprint for Multi-Voltage Panel Variants: The SZR Series socket compatibility across coil voltage variants (12VDC through 220VAC) allows a single panel layout to serve multiple export markets by changing only the relay, not the socket wiring.
• High Insulation Resistance (≥1,000 MΩ at 500VDC): Supports accurate leakage current measurement during panel acceptance testing and ensures compliance with IEC 60204-1 insulation requirements for industrial machinery.
• UL/CSA/CE Certification: Satisfies the approval requirements for machine export to North America (UL 508A panel certification) and the European Union (Machinery Directive), reducing third-party certification burden for OEM builders.
• Long Electrical Life at Rated Load: 100,000 operations at full 10A resistive load translates to approximately 2.7 years of continuous service at 1 switching cycle per minute — a realistic figure for HVAC damper or pump sequencing applications.

Quality Assurance & Global Logistics

Every Honeywell SZR-LY2-N1 110VAC unit supplied through siemensplc.com is sourced from verified supply channels with full lot traceability. Manufacturer markings, date codes, and packaging integrity are inspected against Honeywell’s authentic product references prior to dispatch. Certificate of Conformance (CoC) documentation is available upon request for quality audit and incoming inspection purposes.

Shipments originate from our warehouse in Xiamen, China — a major port city with direct access to DHL, FedEx, UPS, and SF Express international networks. Standard express delivery to Europe, Southeast Asia, the Middle East, and North America typically completes in 3–7 business days. For bulk orders, sea freight consolidation via Xiamen Port is available with full export documentation including commercial invoice, packing list, and customs declaration. All shipments include tracking information provided at dispatch. The 12-month warranty covers manufacturing defects confirmed through technical evaluation; warranty claims are processed with replacement dispatch within 5 business days of fault confirmation.

Contact Information

Email: [email protected]
WhatsApp: +86 18359268345
Web: siemensplc.com
Location: Xiamen, China
© 2026 siemensplc.com. All rights reserved.