ABB CT.ARS.21S Asymmetrical Repeating Cycle Time Relay, 24–240V AC/DC 1C/O 0.05s–300h

1. Product Overview

ABB CT.ARS.21S is a high-precision asymmetrical repeating cycle time relay from ABB’s premium CT-S timing relay series, designed for independent on/off cyclic timing control in industrial automation systems. Featuring universal24–240V AC/DC ultra-wide voltage compatibility, single 1C/O SPDT changeover contact, and industry-grade adjustable timing range of0.05 seconds to 300 hours, this DIN rail mount timer delivers flexible asymmetrical cyclic operation logic. Unlike symmetrical cycle timers with fixed equal on/off intervals, the CT.ARS.21S allows independent adjustment of ON duration and OFF duration, meeting complex non-uniform cyclic control demands. With anti-interference industrial design, simple DIP switch configuration and wide environmental adaptability, it serves as a core timing component for automated machinery, ventilation systems, cyclic warning devices and sequential process control equipment.

2. Complete Technical Specifications

2.1 Core Electrical & Timing Parameters

The ABB CT.ARS.21S supports universal global industrial voltage input, covering 24V–240V AC and 24V–240V DC, eliminating model replacement troubles for different regional power supply standards. Equipped with one 1C/O SPDT changeover contact rated at 4A/250V AC resistive load, it stably drives auxiliary control loops such as contactors, solenoid valves and indicator lights. The ultra-wide timing range spans 0.05s to 300h, covering ultra-short pulse cycle, medium precise cyclic timing and ultra-long intermittent operation scenarios. Adopting high-precision dedicated timing chips, the module maintains stable timing accuracy and repeatability under voltage fluctuations and long-term continuous operation, avoiding timing deviation and signal disorder.

2.2 Exclusive Asymmetrical Cycle Working Logic

The core highlight of the ABB CT.ARS.21S is its professional asymmetrical repeating cycle function. It supports separate parameter setting for ON-time and OFF-time, enabling non-equal cyclic operation. Users can freely configure long ON + short OFF or short ON + long OFF timing logic according to on-site process requirements, which cannot be realized by ordinary symmetrical cycle timers. The timing modes are switched and calibrated via onboard DIP switches and precision potentiometers without rewiring or program modification. The module starts cyclic operation immediately after power-on, achieving fully automatic intermittent cycle control, and supports continuous cyclic work without pause, adapting to diversified cyclic automation control logic.

2.3 Mechanical & Environmental Performance

The ABB CT.ARS.21S adopts compact industrial-grade housing with standard 35mm DIN rail mounting, realizing tool-free quick installation and replacement, effectively saving control cabinet space and optimizing wiring layout. It featuresIP50 front dustproof protection and IP20 terminal safety protection, isolating internal circuits from cabinet dust and particle interference. The wide operating temperature range of -25°C to +60°C adapts to high-temperature workshops, low-temperature equipment rooms and temperature-fluctuating industrial environments. Standard anti-loose screw terminals ensure stable wiring connection, preventing virtual connection faults caused by long-term mechanical vibration and ensuring long-term stable operation of the timing system.

3. Core Product Features & Advantages

3.1 Independent Asymmetrical Cycle Timing

Breaking the limitation of traditional symmetrical cycle timers, the ABB CT.ARS.21S supports independent adjustment of switch-on duration and switch-off duration. It perfectly solves the industry pain point of fixed equal cycle intervals, fully meeting complex non-uniform cyclic control requirements such as intermittent equipment operation, delayed cyclic start and irregular timing switching. The professional asymmetrical cycle design greatly improves the flexibility of automation timing logic, avoiding the need for multiple timers or PLC programming to achieve complex cyclic control, simplifying system design and reducing failure points.

3.2 Ultra-Wide Universal AC/DC Voltage Adaptation

With 24–240V AC/DC full-range universal voltage design, the CT.ARS.21S is compatible with almost all global industrial and commercial power supply systems. It unifies spare part models for engineering projects and equipment manufacturers, reducing procurement costs and inventory pressure. Whether it is AC commercial power or DC control power, the single module can be universally deployed, which is very suitable for cross-regional engineering projects and standardized automated equipment supporting, with extremely high versatility and compatibility.

3.3 High Precision & Industrial Anti-Interference Ability

Built with ABB’s mature industrial circuit technology, the CT.ARS.21S is equipped with high-precision timing chips and optimized electromagnetic shielding structure. It effectively resists industrial common interference such as voltage surges, harmonic fluctuations and electromagnetic radiation, ensuring zero deviation in long-term cyclic timing. The stable circuit structure avoids timing drift and output lag, providing reliable and accurate cyclic timing guarantee for automated production lines and process equipment, and improving the overall stability of industrial control systems.

3.4 Simple Configuration & High Cost-Performance

The module adopts intuitive onboard DIP switch and potentiometer adjustment design, allowing technicians to complete mode switching and timing parameter calibration in seconds without professional programming tools. The integrated multi-function design replaces multiple single-function timing modules, simplifying cabinet wiring and engineering deployment. With compact size, stable performance and long service life, it balances high-precision industrial timing performance and low engineering cost, becoming the preferred cost-effective solution for standardized cyclic timing control scenarios.

4. Industrial Application Scenarios

The ABB CT.ARS.21S asymmetrical cycle time relay is widely used in industrial and commercial automation non-uniform cyclic control scenarios. It is mainly applied to intermittent operation control of ventilation fans and cooling equipment, irregular cyclic start-stop control of conveying machinery, cyclic warning light control, timing switching of auxiliary production equipment, and intermittent operation protection of process industrial equipment. It is also suitable for building automation timing control, environmental protection equipment cyclic operation and old automation system transformation, helping enterprises realize intelligent, standardized and low-energy-consumption cyclic automatic control.

5. Frequently Asked Questions (FAQ)

5.1 What is the core function of ABB CT.ARS.21S?

The ABB CT.ARS.21S is a professional asymmetrical repeating cycle time relay, supporting independent adjustment of ON and OFF timing intervals to realize non-uniform cyclic automatic operation, which is the biggest difference from ordinary symmetrical cycle timers.

5.2 What voltage and timing range does CT.ARS.21S support?

It supports 24–240V AC/DC universal wide voltage, with an ultra-wide timing adjustment range of0.05s to 300h, covering all conventional industrial short and long cycle timing scenarios.

5.3 What contact specification does this timing relay adopt?

The CT.ARS.21S is equipped with a 1C/O SPDT changeover contact with a rated load of 4A/250V AC, which can stably drive various industrial auxiliary control loops.

5.4 What is the advantage of asymmetrical cycle timing?

Asymmetrical cycle allows separate setting of working time and standby time, which can adapt to complex and irregular cyclic production processes that fixed equal cycle timers cannot meet, greatly improving the flexibility of automation control logic.