WAGO 859 Series Relay Module 12VDC SPDT

Technical Overview

Miniature switching relay module with 12 VDC coil, SPDT contact, 5 A / 250 VAC switching, CAGE CLAMP® connections for DIN rail mounting.

Key Features

1 changeover contact (SPDT) for versatile switching applications.
Nominal input voltage of 12 V DC, compatible with common control systems.
Maximum switching current of 5 A, suitable for various loads.
Maximum switching voltage of 250 V AC.
CAGE CLAMP® connection technology ensures reliable and vibration-proof wiring.
Designed for DIN-rail mounting with a narrow 6 mm module width, optimizing panel space.
Equipped with a red LED status indicator for immediate operational feedback.
Contacts made from AgSnO2 (Silver Tin Oxide) for enhanced arc resistance and durability.
Features a pollution degree of 2, indicating suitability for most industrial environments.
Mechanical life of 5 x 10^6 switching operations for long-term reliability.
Ambient operating temperature range from -25 °C to +50 °C.

Technical Specification Matrix

Parameter	Value
Nominal Input Voltage	12 VDC
Input Voltage Range	-15% … +20% (of UN)
Nominal Input Current (at UN)	17 mA
Number of Changeover/Switchover Contacts	1
Contact Material	AgSnO2
Limiting Continuous Current	5 A
Inrush Current (resistive, max.)	20 A / 0.02 s (AC)
Switching Voltage (max.)	250 VAC
Switching Power (resistive, max.)	1250 VA AC
Recommended Minimum Load	10 VDC / 10 mA; 24 VDC / 1 mA
Pull-in Time (typ.)	15 ms
Drop-out Time (typ.)	25 ms
Bounce Time (typ.)	3.5 ms
Electrical Life (NO; resistive load; 23 °C)	50 x 10^3 switching operations
Mechanical Life	5 x 10^6 switching operations
Switching Frequency (with/without load, max.)	6 min⁻¹ / 180 min⁻¹
Status Indicator	Red LED
Rated Voltage	250 V
Rated Surge Voltage	4 kV
Pollution Degree	2
Dielectric Strength, Control/Load Circuit (AC, 1 min)	4 kVrms
Dielectric Strength, Open Contact (AC, 1 min)	1 kVrms
Connection Technology	CAGE CLAMP®
Solid Conductor Size	0.08 … 2.5 mm² / 28 … 14 AWG
Mounting Type	DIN-35 rail
Ambient Operating Temperature	-25 °C … +50 °C
Storage Temperature	-40 °C … +70 °C
IP Rating	IP20
Physical Weight (kg)	0.02
Dimensions L x W x H (cm)	5.6 x 0.6 x 9.1

Industrial Applications

1. Industrial Control Panel for Small Motor/Solenoid Actuation

This relay module is ideal for industrial control panels where low-voltage control signals (12 VDC from a PLC or microcontroller) need to actuate small motors, solenoids, or other loads up to 5 A / 250 VAC. Its compact 6 mm width allows for high-density mounting on DIN rails, maximizing space efficiency in crowded enclosures. The SPDT contact configuration offers flexibility for control logic, such as forward/reverse control or alarm signaling. The CAGE CLAMP® connections ensure reliable, vibration-resistant wiring, crucial in industrial environments.

Problem Solved

Provides reliable, isolated switching of higher voltage AC/DC loads using a low-voltage DC control signal in a space-constrained industrial control panel.

12VDC Control250VAC/5A SwitchingDIN Rail MountingSPDTCAGE CLAMP®

2. Building Automation for Lighting and HVAC Control

The WAGO 859-303 can be integrated into building automation systems to control lighting circuits or small HVAC components. Its 12 VDC coil can be directly driven by building management system controllers, while the 5 A / 250 VAC switching capacity is sufficient for individual light fixtures or fan coil units. The narrow 6 mm module width minimizes the footprint within electrical distribution boards, and the red LED indicator provides local status indication for maintenance and troubleshooting.

Problem Solved

Enables efficient and space-saving control of building electrical loads from a low-voltage automation system, providing clear operational status.

12VDC Control250VAC SwitchingCompact DesignLED IndicatorDIN Rail

3. Signal Isolation and Interfacing in Process Instrumentation

In process instrumentation, this relay module serves as an effective interface for signal isolation between sensitive 12 VDC control electronics and field devices operating at higher voltages or with inductive characteristics. The 4 kV dielectric strength between control and load circuits ensures robust electrical isolation, protecting control systems from transient voltages. Its AgSnO2 contacts are well-suited for switching inductive loads, and the CAGE CLAMP® connections provide secure, maintenance-free wiring in environments prone to vibration.

Problem Solved

Offers critical electrical isolation and robust switching capabilities for interfacing disparate voltage levels and protecting sensitive control circuitry in industrial process environments.

Electrical Isolation12VDC Input250VAC OutputAgSnO2 ContactsCAGE CLAMP®