WAGO 857-161 Basic Solid-State Relay

Technical Overview

Compact 24 VDC input solid-state relay with 3A output, ideal for high-density industrial control.

Key Features

Solid-state relay
Pluggable module for easy replacement
2-wire connection circuit type
High dielectric strength: 3.75 kVrms (control/load circuit)
Wide operating temperature range: -30 to 80 °C
Compact, slim-line design with 5 mm width
High switching frequency: ≤ 350 Hz

Technical Specification Matrix

Parameter	Value
Nominal Input Voltage	24 VDC
Input Voltage Range (High Level)	18.8 - 31.2 VDC
Output Voltage Range	0 - 30 VDC
Limiting Continuous Current	3 A
Max. Make Current (Resistive)	15 A / 0.01 s (AC)
Min. Switching Current	50 µA
Turn-on Time	≤ 100 µs
Drop-out Time	≤ 600 µs
Switching Frequency	≤ 350 Hz
Dielectric Strength (Control/Load Circuit, AC, 1 min)	3.75 kVrms
Operating Temperature	-30 … 80 °C
Storage Temperature	-40 … 100 °C
Mounting Type	Pluggable module
Physical Weight (kg)	0.005
Dimensions L x W x H (cm)	2.8 x 0.5 x 1.5

Industrial Applications

1. Industrial Automation Control Panels

The WAGO 857-161 is perfectly suited for high-density mounting in industrial control panels, enabling efficient switching of low-voltage DC loads in PLC-driven automation systems. Its 5 mm width optimizes panel space.

Problem Solved

Its compact form factor allows for maximum component density, while solid-state operation ensures a long electrical service life and high switching frequency (≤ 350 Hz), effectively controlling small motors, valves, and indicators with reliability.

PLC controlHigh-density mountingDC load switchingPanel space optimizationHigh switching frequency

2. Signal Isolation and Interfacing

This solid-state relay excels in providing robust electrical isolation and seamless interfacing between control systems and diverse loads, safeguarding sensitive electronics from industrial transients.

Problem Solved

With a dielectric strength of 3.75 kVrms, it effectively isolates 24 VDC control signals from 0-30 VDC output loads, mitigating voltage spikes and ground loop issues in electrically noisy industrial environments, acting as a reliable optocoupler replacement.

Electrical isolationGalvanic separationSignal conditioningTransient protectionOptocoupler replacement

3. Temperature-Resilient Switching in Harsh Environments

The WAGO 857-161 is ideal for deployment in industrial machinery and control enclosures subjected to significant temperature fluctuations, maintaining operational integrity where conventional relays might fail.

Problem Solved

Its broad operating temperature range of -30 to 80 °C ensures reliable performance in challenging conditions, such as unheated facilities, outdoor cabinets, or manufacturing processes with extreme ambient temperatures, extending the lifespan and stability of control systems.

Temperature resilienceHarsh environmentsWide operating temperatureRobust controlIndustrial machinery