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 Relays are triggered/initiated by either:

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

Different Types of Timer Relays

Timer relays are essential for controlling various industrial and automation processes. Common types include:

On Delay (Time delay starts on the application of voltage)

On delay timer relays initiate a time delay upon receiving voltage. Once the delay time elapses, the relay's contacts close, activating the connected circuit. These delay timers are ideal for applications like motor starting or delayed lighting.

Off Delay (When a voltage is applied the relay is ready to accept a trigger)

Off delay timer relays start timing when the voltage is removed. The relay's contacts remain closed during the delay, opening only after the set time has passed. Common applications for off delay timers include fan cooling or alarm systems with delayed shutdowns.

Single Shot (One-shot)

Single shot timer relays provide a fixed time delay after receiving a trigger signal. The relay contacts close for the predetermined time, then open automatically. This type of voltage timer relay is often used for precision timing in applications like conveyor belt control or automated dispensing systems.

Interval On (Interval) and Flasher (On First/Off First)

Interval on and flasher timer relays are designed for applications requiring cyclical on-off patterns. They can alternate between on and off states with adjustable delay times, making them suitable for tasks like flashing lights or intermittent alarms.

Repeat Cycle (When a voltage is applied the relay contacts change state and the timer starts)

Repeat cycle timer relays change their contact state each time voltage is applied, initiating a new timing cycle. This type of timer relay is useful for applications that need continuous repetition, such as automatic door openers or cyclic machinery controls.

Difference Between Timer Relay and Electromechanical Relay

The difference between the timer relay and electromechanical relay is 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 timer relay, it is important to consider the kind of delay required for your application.

Applications of Timer Relays

Delay Relays are typically used in industrial applications and OEM equipment play an important role for many industrial processes such as small panel or sub-panels requirements.

Lighting circuits
Motor start control
Sensitive equipment
Safety control
Convey or belt sequence delay

How to Choose the Right Timer Relay for Your Needs

Selecting the appropriate timer relay involves considering several factors to ensure optimal performance and compatibility with your application. Key considerations include the required timing function (on delay, off delay, single shot, etc.), time range, voltage rating, contact configuration, and mounting style.

Additionally, environmental conditions and special features like repeat cycles or adjustable delays should be factored in. RS offers a wide range of reliable, high-quality timer relays from trusted brands, ensuring you can find the perfect solution to meet your specific needs and ensure seamless integration into your project.

How to Order Timer Relay from RS

RS is a trusted supplier of high-quality timer relays from leading brands like ABB, Omron, Schneider Electric, and more. You have multiple convenient options to order from RS in Hong Kong. The easiest method is to order online through our website, where you can browse a wide selection of products, place your order, and choose delivery options that range from next-day delivery to local branch collection. Alternatively, you can place your order by calling 852 2421 9898.

We also offer the option to set up a blanket order for businesses requiring frequent timer relays. This allows you to use a single order number for multiple purchases with a pre-set spending limit. Simply inform us of your order limit, and we will track your transactions and notify you once the limit is reached. To set up a blanket order, call RS at 852 2421 9898.