Coupling Relays
What is a coupling relay?
A coupling relay (also known as an interface relay) acts as an indispensable link between the control level and the field level in automated systems. Its primary purpose is to adapt different voltage levels and galvanically isolate signals from each other. Since modern PLC outputs often only supply low currents, the coupling relay takes on the task of reliably switching larger loads while simultaneously protecting sensitive electronics from process feedback. Thanks to their slim design, these relays save valuable space in the control cabinet and increase the longevity of the entire control infrastructure.
What are the features of coupling relays?
- Galvanic isolation: They ensure safe electrical isolation between the control circuit and the load circuit.
- Compact width: Thanks to their narrow housing designs, they enable extremely high packing density on the DIN rail.
- Level adjustment: They easily convert different signal voltages, such as from 24 V DC to 230 V AC.
- Status display: Integrated LEDs provide immediate visual control over the current switching status of the relay.
- Simple wiring: Modern connection technologies such as push-in or screw terminals significantly reduce installation effort.
- Replaceable relay inserts: In many models, the switching element can be removed and replaced for servicing without dismantling the wiring.
What are the areas of application for coupling relays?
- PLC peripherals: They amplify the weak output signals from programmable logic controllers for powerful actuators.
- System protection: Coupling relays protect control outputs from inductive voltage peaks and short circuits from the field.
- Signal multiplication: A single control output can switch several independent circuits simultaneously via the relay.
- Building automation: Here they are used to couple BUS systems with lighting or blind control.
- Mechanical engineering: They are used to decouple sensors and actuators in order to minimize electromagnetic interference.
Our coupling relays at a glance:
| Type |
contacts |
1 / 2 channel wiring | Width in mm | Reactiontime | Approvals | |
| Coupling Relays |
|
1 changeover contact |
1 | 6,2 | 15 ms |  |
|
|
2 changeover contact |
1 | 17,5 | < 40 ms | |
|
|
|
2 changeover contact |
1 | 16,5 | < 20 ms | |
|
|
|
4 changeover contact |
1 | 31,5 | < 20 ms | |
|
|
|
4 |
1 | 22,5 | |
