KS2712 BECKHOFF 2-Channel Solid State Relay Terminal (Triac)

Product Overview

The KS2712 (KS2712) is a specialized 2-channel digital output terminal designed for switching AC loads using solid-state technology (Triacs). Operating within the Beckhoff Bus Terminal system, it is specifically engineered for high-cycle applications where traditional mechanical relays would fail due to contact wear. With a voltage range of 12 to 230 V AC, the KS2712 is the primary B2B solution for controlling reversible motors, such as those found in blinds, shutters, and small actuators. The "KS" designation indicates that this model features a pluggable wiring level, allowing for rapid field replacement without disconnecting individual conductors.

Hardware Architecture and Switching Logic

The KS2712 utilizes two "make contacts" implemented as Triacs. This solid-state design enables an incredibly fast switch-on time of 0.1 ms, significantly faster than mechanical alternatives. Because it is a Triac-based device, the switch-off time is $T/2$ (half a cycle), as the device naturally stops conducting at the next zero-crossing of the AC sine wave.

A critical feature of the KS2712 is its surge voltage protection (> 275 V AC) and high peak current capability, handling up to 40 A for short durations (16 ms). This makes it exceptionally resilient against the inrush currents typical of inductive loads like small motors and solenoids. The terminal provides superior safety with a dielectric strength test of 3750 V AC, ensuring total galvanic isolation between the K-bus logic and the high-voltage field side.

Technical Specifications

Technical FAQs

Can the KS2712 be used to reverse a motor directly?

Yes. The KS2712 is specifically designed for reversible AC motors (like those used in blinds). By using the two channels to control the "Forward" and "Reverse" windings, you can manage the direction of travel. However, ensure that the PLC logic prevents both outputs from being active simultaneously to avoid motor damage.

What is the advantage of "KS" pluggable wiring?

The KS series features a detachable neck. If a terminal needs to be replaced, you can unplug the entire wiring block as a single unit and insert it into a new terminal. This eliminates the risk of wiring errors and drastically reduces "Mean Time to Repair" (MTTR) in industrial environments.

Why is there a leakage current in the OFF state?

Solid-state switches (Triacs) naturally have a small amount of leakage current (typ. 0.8 mA). While this is harmless for motors and solenoids, it is important to verify that very low-power loads (like some LED indicators) do not remain faintly lit when the output is technically "OFF."

Engineering & Installation Guide

• Load Compatibility: The KS2712 is optimized for ohmic and inductive loads. For motors, ensure the rated current does not exceed 0.5 A per channel. If your motor requires a higher current, use this terminal to trigger a larger power contactor.

• Wiring and Termination: Use a screwdriver to actuate the spring clamps. The KS2712 accepts wire cross-sections from 0.08 to 1.5 mm² (AWG 28–16). Ensure a stripping length of 9 to 10 mm to guarantee a gas-tight connection.

• Hazardous Area and Marine Use: With ATEX Zone 2 and DNV GL approvals, this terminal is certified for use in explosive atmospheres and maritime applications. Always install the terminal in an enclosure that meets the IP requirements of the specific environment (e.g., a stainless steel cabinet for offshore use).

Engineering Advantages

The KS2712 provides a maintenance-free switching solution for AC applications. Its solid-state design eliminates the arcing and mechanical wear associated with standard relays, ensuring a virtually unlimited switching lifespan. Compliance with EN 61000-6-2/4 for EMC ensures that the high-speed switching does not introduce interference into the control system. For B2B machine builders, the KS2712 offers a globally-certified, compact, and highly reliable method for controlling small AC motion components, backed by the flexibility of the Beckhoff Bus Terminal ecosystem.