WAGO 788-311 Interface Relay Module

Technical Overview

DIN-rail mountable interface relay module with 12VDC coil, DPDT contacts, 8A/250VAC switching, and red LED status indicator.

Key Features

12 VDC nominal input voltage (coil) with ±10% range.
DPDT (2 changeover) contacts with Silver Nickel (AgNi 90/10) material.
Limiting continuous current of 8 A and switching voltage up to 250 VAC.
Red LED status indicator for visual operational feedback.
DIN-35 rail mountable for easy integration into control panels.
Push-in CAGE CLAMP® terminals for secure, tool-free wire connections.
Mechanical life of 30 million switching operations.
Operating temperature range from -40°C to +70°C.
IP20 protection type.
Reinforced insulation between coil and contacts.

Technical Specification Matrix

Parameter	Value
Nominal Input Voltage (Coil)	12 VDC
Input Voltage Range	±10% (10.8-13.2 VDC)
Nominal Input Current (Coil)	36 mA
Contact Configuration	DPDT (2 Changeover Contacts)
Contact Material	AgNi 90/10
Limiting Continuous Current	8 A
Switching Voltage (Max)	250 VAC
Switching Capacity (AC-15)	3 A / AC 250 V
Switching Capacity (DC-13)	2 A / DC 24 V
Pull-in Time (typical)	8 ms
Drop-out Time (typical)	13 ms
Bounce Time (typical)	10 ms
Mechanical Life	30 x 10^6 switching operations
Electrical Life (NO; resistive load; 23 °C)	10 x 10^3 switching operations
Status Indicator	Red LED
Protection Type (IP Rating)	IP20
Connection Technology	Push-in CAGE CLAMP®
Solid Conductor Size	0.34 … 2.5 mm² / 22 … 14 AWG
Fine-stranded Conductor Size	0.34 … 2.5 mm² / 22 … 14 AWG
Strip Length	9 … 10 mm
Mounting Type	DIN-35 rail
Operating Temperature	-40 … 70 °C
Storage Temperature	-40 … 70 °C
Rated Voltage	250 V
Rated Surge Voltage	4 kV
Pollution Degree	3
Dielectric Strength (Control/Load Circuit, AC, 1 min)	5 kVrms
Dielectric Strength (Open Contact, AC, 1 min)	1 kVrms
Dielectric Strength (Load/Load Circuit, AC, 1 min)	2.5 kVrms
Physical Weight (kg)	0.05
Dimensions L x W x H (cm)	8.6 x 1.5 x 5.4

Industrial Applications

1. Industrial Control Panel Signal Isolation

Used in industrial control panels to safely isolate low-voltage PLC/controller outputs (12VDC) from higher voltage (e.g., 230VAC) or higher current loads, such as small motors, solenoids, or indicator lights.

Problem Solved

Prevents damage to sensitive control electronics from load-side voltage spikes or current surges and allows for flexible switching of different voltage/current levels using a standard 12VDC control signal. The DPDT contacts offer versatile switching options for complex control logic.

Signal isolationPLC outputIndustrial controlVoltage conversionCurrent amplificationDPDT switching

2. Building Automation for HVAC/Lighting Control

Integrating into building automation systems for switching HVAC dampers, small fan motors, or lighting circuits where the central control system operates on 12VDC logic, but the controlled devices require 230VAC at moderate current.

Problem Solved

Provides a reliable interface for a 12VDC building management system to control AC-powered components up to 8A, while offering visual status indication via the integrated LED for easy troubleshooting in often crowded electrical cabinets. Its compact, DIN-rail mountable design saves space.

Building automationHVAC controlLighting controlLow voltage interface250VAC switchingStatus indicator

3. Machine Auxiliary Circuit Switching

Employed in various machine auxiliary circuits where a 12VDC signal is used to control non-safety-critical indicators, small actuators, or to provide feedback to other 12VDC inputs.

Problem Solved

Allows a machine's control system 12VDC output to confidently switch diverse auxiliary loads (up to 8A AC or 2A/24VDC for DC loads) for non-critical functions. DPDT contacts provide flexibility for multiple feedback paths or indicator activation. The IP20 rating is suitable for typical industrial control cabinet environments.

Machine feedbackAuxiliary switching12VDC controlDPDTControl cabinetIndustrial machinery