In the field of industrial automation, time delay relays play an important role, especially in controlling the start and stop of equipment in terms of time. In this article, you will learn 1. What is time delay, 2. The difference between on and off delay timers, 3. How to choose a suitable time delay relay, 4. Other most frequently asked questions, now let’s take a deep look!
Table of Contents
What Is A Time Relay?
A time relay is a time-controlled relay that activates or deactivates its output after receiving an input signal. The time delay relays are critical in automated control systems because they ensure that operations are performed in a predetermined time sequence.
What Is An On Delay Timer?
The on-delay timer does not respond immediately after receiving an activation signal, but waits for a preset period of time before activating its output. Typical applications of this timer include delayed motor start-up, delayed lighting system turn-on, etc.
Advantages Of On Delay Timer
- Prevent system shocks, such as current spikes when motors start.
- Ensure system stability, such as delaying the start of sensitive equipment after power is applied.
What Is An Off Delay Timer?
An off-delay timer responds immediately when the input signal is removed, but its output remains active until a preset time delay has elapsed. This type of timer is often used to ensure that equipment continues to operate for a certain period of time after power is removed, such as emergency lighting systems or security door control systems.
Advantages Of Off Delay Timer
- Ensure that the equipment is shut down safely, such as keeping the lights on for a period of time after a power outage.
- Avoid damage to the equipment caused by sudden power outages.
On Delay Timer and Off Delay Timer Circuit Diagram
Off delay timer circuit, source: https://youtu.be/RwSga-zQy0I?si=_1rPcis-2f1d8v7C
On delay timer circuit, source: https://youtu.be/RwSga-zQy0I?si=_1rPcis-2f1d8v7C
On Delay Timer Vs Off Delay Timer Differences
| Characteristics | On delay timer | Off delay timer |
|---|---|---|
Response time |
Delay after input signal |
Delayed shutdown of load after input signal is removed |
Output state change |
Change after the delay |
Change immediately, and revert after the delay ends |
Purpose |
Delayed start |
Delayed stop |
How To Choose The Right Time Delay Relay?
When selecting a suitable time relay, the following factors should be considered:
- The required time delay range: we can provide many kinds of different delay ranges time relays, such as our ST3PA-B on delay time is maximum 6 minutes, our DIN Rail Timer Relay, TMS2, Power-on Delay maximum on delay time is up to 1 hour, the off delay relay such as ST3PF off delay time can be maximum 30 minutes.
- The load capacity of the contacts: As for the time relay output contact capacity, the higher the better, but please also note that the price will be higher as well.
- The input voltage and control signal type: The time delay working voltage can be as wide as AC90-265V or DC12V, DC24VDC, DC5VDC etc. Make sure the working voltage is available in your equipment.
- The specific requirements of the application scenario: Different equipment may need different time delay relays no matter from the dimension aspect to the operation aspect, choosing the suitable and comfortable one to use is also important.
- Installation method: The time relays always have two popular installation methods, one is DIN rail mounting, it is more convenient to be installed with other components, the other is panel mounting, panel mounting is much easier for the user to adjust the delay time.
FAQ
What is the difference between the on-delay and off-delay timers?
The on-delay timer activates the output with a delay after the input signal, while the off-delay timer activates the output immediately after the input signal is removed, but keeps it activated for a period of time.
How do I set the delay time of a time relay?
It is usually set via a knob, or push button. Different delay timers might have different operation methods. We, Lorentzzi, can supply various kinds of delay timers with different operation methods. Contact us now to learn more.
Conclusion
In summary, the power-on delay timer is mainly used to delay the startup of the load when the power is turned on, and the power-off delay timer is mainly used to delay the shutdown of the load when the power is turned off. At Lorentzzi, you can find many different on delay timers and off delay timers, and we only produce the best and most reliable products to meet our customers’ requirements.
