Description

AT-372 Ultra Timer: Versatile Programmable Timing Relay

The AT-372 Ultra Timer is a highly versatile, crystal-controlled programmable timing relay designed for precise and reliable time-based control across a wide range of industrial and commercial applications. Developed by United Automation Ltd, this advanced timing module offers exceptional flexibility with selectable time periods from just 1 second up to 64 weeks.

Designed for dependable performance, the AT-372 features automatic DC voltage selection, dual relay outputs capable of switching mains power, and configurable trigger and reset polarity for seamless system integration. Its crystal-controlled timing ensures high accuracy, while the intuitive DIL switch configuration makes setup simple and fast.

Compact, robust and engineered for demanding environments, the AT-372 provides precise timing control for applications such as fire door monitoring, access systems, industrial automation, HVAC sequencing and alarm or lighting control.

Key Features

• Wide programmable timing range from 1 second to 64 weeks

• Crystal-controlled timing for high accuracy

• Four selectable operating modes for flexible control strategies

• Automatic input voltage selection (9.5V to 30V DC)

• Double pole relay capable of switching mains loads up to 8A

• Jumper-selectable trigger and reset input polarity

• Optional pulse activation with automatic 20-second relay dropout

• Simple DIL switch time configuration using lookup table

• LED status indication with flash patterns for mode identification

• Compact enclosure for easy installation

Benefits

• Provides highly accurate long-duration timing control

• Supports multiple automation and monitoring strategies

• Simplifies installation with automatic voltage detection

• Enables direct mains switching via robust relay contacts

• Offers flexible system integration through configurable inputs

• Reduces setup time with intuitive DIL switch programming

• Delivers reliable operation across industrial temperature ranges

Typical Applications

The AT-372 Ultra Timer is ideal for:

• Fire door monitoring and safety systems

• Access control and security timing

• HVAC automation and sequencing

• Industrial process timing and control

• Lighting and alarm delay functions

• Equipment start-up or shutdown sequencing

• General timed relay switching

Technical Specifications

Timing & Control

• Time range: 1 second to 64 weeks

• Time setting method: DIL switch with lookup table

• Time accuracy: crystal controlled

• Operating modes: 4 selectable modes

• Pulse activation option: available in selected modes

Supply & Electrical

• Supply voltage: 9.5V to 30V DC (auto-selected)

• Current consumption: approx. 34mA active, 3mA quiescent

• Maximum input voltage: 30V

• Minimum input voltage: 4V

• Peak input current: 5mA

Trigger & Reset Input Levels

• LOW: <220Ω to ground or <0.8V

• HIGH: >4700Ω to ground or >4V

Relay Output (Double Pole Contacts)

• AC switching: up to 250V, 8A (non-inductive load)

• DC switching: up to 30V, 5A (non-inductive load)

• Minimum switching level: 5V @ 10mA

Environmental Conditions

• Operating temperature: −10°C to +60°C

• Maximum humidity: 80% non-condensing

Physical Characteristics

• Dimensions: approx. 78 × 47 × 22 mm

• Weight: 80g

• Supplied in strong cardboard carton with mounting fixers

Operating Modes

Mode A — Delayed Activation
Trigger initiates timing cycle. Relay activates after timeout.
With auto link fitted, relay drops out after ~20 seconds and waits for next trigger.

Mode B — Timed Output
Trigger immediately activates relay for the set duration, then relay deactivates and resets.

Mode C — Continuous Trigger Monitoring
Trigger must remain active for entire timing period.
If trigger remains active after timeout, relay activates.
Often used for monitoring conditions such as door open duration.

Mode D — Maintained Activation
Similar to Mode C, but relay remains energised until trigger is removed.
Optional auto-link allows timed dropout after activation.

Installation & Operation

Time periods are set using DIL switches covering seconds, minutes, hours, days and weeks.
Trigger and reset polarity are configured via jumper links.
Operating mode is selected by jumper configuration and confirmed by LED flash pattern at power-up.

For further details, please reach out to United Automation Ltd.

3762065, A-AT-372, 260-6580, HK01118