Timer Relays

Timer relays are versatile electrical devices that control the timing of events in a circuit. They introduce a time delay between the activation of the relay and the switching of its contacts. Timer relays are commonly used in industrial automation, lighting control, and various other applications where precise and adjustable timers are needed.

What are Timer Relays?

A timer relay is a control relay with a time delay function built in. They serve as a combination of an electromechanical output relay and a control circuit, in which contacts can be opened or closed before or after a pre-selected timed interval. Relays can be normally open or normally closed and can be used to delay timed functions from milliseconds to hours or even days.

Timer Relay or Electromechanical Relay?

The difference between the timer relay and electromechanical relay is that when the output contacts open or close. On a conventional control relay, the contacts are opened or closed when a voltage is applied and removed from the coil, however, for timer relays the contacts will open or close before or after an intentional time period. When choosing the right time delay switch, it is important to consider the kind of delay required for your application.

What are the Types of Timer Relays?

The most common timing function of delay relays are:

• On Delay (Time delay starts on the application of voltage)
• Off Delay (When a voltage is applied the relay is ready to accept a trigger)
• Single Shot (One-shot)
• Interval On (Interval) and Flasher (On First / Off First)
• Repeat Cycle (When a voltage is applied the relay contacts change state and the timer starts)

When choosing the appropriate time delay switch for your application, it is important to understand the difference between the types of timer delay relays, considering what should initiate the delay and if it should start at the same time as the application, as well as when the voltage is released.

Timer relays are triggered/initiated by either:

• Voltage being applied or
• The closing or opening of a trigger signal

How to Choose a Timer Relay that’s Right for You?

Consider these factors when choosing the right timer relay for your needs:

Understand the Application Needs

Identify the specific purpose and function of the timer relay and the time delay in your system. Determine whether you need an on-delay timer relay (e.g., delaying the start of a motor after a machine is turned on), an off-delay timer relay (e.g., keeping a fan running for a set time after a machine is turned off), or a combination of both.

Timing Requirements

Assess the precise timing needs of your application. Do you require a fixed time delay or an adjustable timer relay? Consider the range of timing adjustments needed and the desired accuracy.

Type of Timer Relay

Choose the appropriate type of timer relay based on your requirements. Options include electromechanical timer relays, digital timer relays, or solid-state timer relays. Each type has its own advantages and limitations in terms of accuracy, cost, and lifespan.

Voltage and Power Requirements

Ensure the timer relay is compatible with the voltage and power supply of your system. Consider the coil voltage (e.g., 12v, 220v or 240v timer relay switch) and the contact ratings to handle the expected load.

Durability

Evaluate the expected operating conditions and choose a timer relay or delay timer with suitable durability. Factors like temperature range, humidity, and vibration resistance should be considered.

Certification and Standards

Look for timer relays that comply with relevant safety and industry standards, such as UL, CE, or RoHS. This ensures the product meets quality and safety requirements.

Applications of Timer Relays

Timer and delay relays are typically used in industrial applications and OEM equipment, playing an important role in various industrial processes, including those with small panel or sub-panel requirements. Here are some common applications across diverse industries:

F&B

In the food and beverage industry, time delay relays ensure precise control over processes like mixing, cooking, or packaging operations, ensuring product consistency and quality. Additionally, off-delay timer relays can be employed to keep equipment like ovens or refrigerators running for a specified period after a process is completed, preventing spoilage or maintaining optimal storage conditions.

Manufacturing

Timer relays are extensively used in manufacturing automation to control the timing of machine start-up sequences, conveyor belt movements, and robotic arm actions, optimising production efficiency and minimising downtime. Adjustable timer relays provide the flexibility to adapt to different production needs, allowing for quick adjustments and process optimization.

Automotive

In the automotive industry, timer relays enable various time-based functions such as delayed windshield wiper operation, ensuring clear visibility during intermittent rain. Additionally, timer relays can be employed for headlight delay-off, allowing drivers to safely navigate to their destination after parking. 12v timer relays are commonly used in automotive systems as it is the standard voltage used in most vehicles.

Pharmaceutical

Timer relays are essential in pharmaceutical processes, ensuring precise control over critical parameters. They are used to regulate the timing of mixing, heating, or cooling cycles, ensuring product quality and efficacy. Furthermore, timer relays are employed in equipment like autoclaves to guarantee proper sterilisation times, maintaining a sterile environment for pharmaceutical production.

HVAC

Timer relays are used in heating, ventilation, and air conditioning (HVAC) systems to optimise energy efficiency and comfort. They control the timing of fans, compressors, and other components, optimising operation based on occupancy and temperature requirements. Adjustable timer relays can also be used to implement time-of-day schedules or setback functions, reducing energy consumption during unoccupied periods.

Water Treatment

Timer relays are crucial in water treatment plants for regulating the timing of pumps, valves, and chemical dosing systems, ensuring consistent water quality and efficient operation. By precisely controlling the duration of treatment cycles, timer relays help maintain compliance with water quality standards.

Building Automation

Timer relays are integrated into building automation systems to enhance control and energy efficiency. They manage lighting schedules, HVAC operation, and access control systems, optimising resource utilisation and occupant comfort. Time delay switches or adjustable timer relays can be programmed to turn lights off during unoccupied hours or adjust HVAC settings based on occupancy patterns, contributing to significant energy savings.

Mining

In the mining industry, timer relays play a role in controlling various equipment and processes. They can be used to regulate the timing of conveyors, crushers, and other machinery, ensuring smooth and efficient operation. Additionally, timer relays or off delay timer relays can be incorporated into safety systems to trigger alarms or initiate shutdowns in case of equipment malfunctions, protecting personnel and preventing accidents.

Energy

In the energy sector, time delay relays and delay timers are critical for controlling generators, switchgear, and other components within power generation and distribution systems, ensuring a stable and reliable power supply. Moreover, they optimise energy utilisation and grid integration in renewable energy systems like solar and wind power installations.

Delivery Information

From digital timer relays to adjustable timer relays, RS Malaysia offers a wide selection of timer relays and time delay switches from leading brands like Schneider Electric, Omron, ABB, and more. Shop timer relays and other essential industrial automation components like monitoring relays and photoelectric sensors with us. For a full overview of our delivery options, including estimated lead times and shipping costs, please visit our Delivery Page.