SKR2-A Automatic Transfer Switch Controller(ATSC)

Product Overview

The SKR2-A automatic transfer switch controller is built around a micro-processor core, designed to deliver precise monitoring and control for dual power supply systems. It accurately detects three-phase or single-phase voltage of dual power supplies (1# and 2#), identifying voltage anomalies such as power loss, overvoltage, undervoltage, phase loss, overfrequency, and underfrequency. Upon detecting such issues, it triggers ATS (Automatic Transfer Switch) switching with a configurable delay, making it suitable for ATS units with or without a breaking position.

A key function is its ability to send a delayed generator start signal when the 1# power supply fails, ensuring seamless backup power activation. Equipped with an RS485 communication interface, the controller supports remote measurement, remote communication, and remote control, enabling integration into intelligent power management systems.

Features

Real-time Monitoring and Flexible Configuration

The controller provides real-time display of 3-phase voltage and frequency for both power supplies, allowing operators to instantly assess system status. Via panel keys, users can configure critical parameters, including power priority (1# priority, 2# priority, or no priority), operation mode (automatic or manual), and transfer logic, adapting to diverse application requirements.

Reliable Relay Outputs

It features pulse-based outputs for breaking and closing operations, with relay contacts optimized for different loads:

· 1# CLOSE, 2# CLOSE, and OPEN relays support 5A AC250V, ideal for controlling low-power switching components.

· The generator start relay (GENS START) handles 7A AC250V/DC28V, ensuring reliable activation of backup generators.
All contacts are passive, enhancing compatibility with external circuits and reducing interference risks.

Independent Dual N-line Design

The controller incorporates an independent dual N-line (neutral line) structure, which ensures electrical isolation between the two power supplies. This design complies with safety standards, preventing short circuits or interference caused by potential differences between neutral lines, and simplifies maintenance by isolating one power source without affecting the other.

Versatile Operation Modes

It supports seamless switching between automatic and manual modes. In manual mode, operators can control ATS switching directly via panel keys, including forced opening (if the ATS has a breaking position) using a dedicated "force open" input port. In automatic mode, the controller autonomously switches between power supplies based on preset priorities or fault conditions, ensuring uninterrupted power supply.

Intuitive Status Tracking and Durable Build

Panel LEDs provide real-time visual feedback of ATS status, such as which power supply is active or if a fault has occurred. Programmable auxiliary relays (AUX.OUTPUT1/2) enable external power supply control for extended system integration. The controller is housed in a modular flame-retardant ABS shell with pluggable terminals, supporting compact embedded installation for space efficiency and easy maintenance. It boasts a protection level of IP55 when equipped with a reinforced waterproof rubber ring, making it suitable for harsh environments.

Applications

The SKR2-A ATS controller is widely used in scenarios requiring reliable power continuity, including:

· Industrial Facilities: Ensures uninterrupted operation of production lines by switching to backup power during mains failures.

· Data Centers: Prevents data loss or downtime by maintaining stable power for servers and cooling systems.

· Healthcare Facilities: Critical for hospitals, where power interruptions could disrupt life-saving equipment.

· Commercial Buildings: Supports lighting, HVAC, and security systems, avoiding disruptions to daily operations.

· Remote Sites: Works with generators in mining, construction, or rural areas where power stability is limited.

FAQ

Q1: How to set power supply priorities and transfer logic?

A1: Power priority (1# priority, 2# priority, or no priority) is configured via panel keys. In automatic mode, the controller switches based on preset logic: if both supplies are normal, it follows the priority setting; without priority, it stays on the current supply until a fault occurs. In manual mode, switching is controlled directly via panel keys.

Q2: What is the load capacity of the relay outputs, and why use passive contacts?

A2: The load capacity varies by relay:

· 1# CLOSE/2# CLOSE/OPEN relays: 5A AC250V (suitable for low-power control circuits like contactor coils).

· Generator start relay (GENS START): 7A AC250V/DC28V (designed for high-power generator startup).

Passive contacts enhance compatibility, allowing integration with external power systems, and reduce internal interference risks.

Q3: What are the benefits of the independent dual N-line design?

A3: This design ensures electrical isolation between the neutral lines of 1# and 2# power supplies, preventing interference or short circuits from potential differences. It meets international standards (e.g., IEC 60947) for safety, and simplifies troubleshooting by allowing maintenance on one supply without affecting the other.