What Is a Time Delay Relay?
Time delay relays help control all kinds of electricity-powered machinery. They can delay the activation or deactivation of equipment, saving energy and preventing accidents.
Upon application of power the contacts change position and remain in that position for the preset time delay. Most reset on loss of power. Some have normally open (NO) contact arrangements and others use normal closed (NC) contacts.
Easy to Install
Time delay relays electromechanically open or close their output contacts at set intervals, allowing them to control power or sequencing operations. They’re used in applications such as air-conditioning systems to hold the blower motor in operation for a specific period of time after the thermostat turns it off, or in laundry machines to operate coin-operated dryers for a designated amount of time. These timed relays help reduce electricity costs and are also useful in industrial machinery to avoid electrical surges from large inductive loads that can damage equipment.
To start timing, a time delay relay is triggered with either a dry-contact control switch, like a float switch, limit switch or push button; or with voltage. When the trigger is energized, the output contacts will open to provide power to your circuit. When the time delay is over, the relay will de-energize to allow the switches to return to their normal position.
Single-function time delay relays have a pin that plugs into a relay socket to make electrical connections with circuits. Multiple time ranges are available to meet a wide variety of applications, from seconds to hours. For larger jobs, multi-function time delay relays offer more versatility with a dial to select the desired setting. These types of time delay relays are ideal for distributing & limiting power to machinery, while keeping circuits neat & tidy in cabinets & load centers.
Easy to Test
Unlike many other electrical devices, which are complicated to test, time delay relays can be tested using a simple multimeter. Simply set the multimeter to ohms and touch one of the coil pins to test for continuity. If the relay has continuity, then it is working properly.
A common use for time delay relays is to schedule industrial machinery to start up or shut down over a set window of time. This helps conserve energy and prevent safety issues such as flammability. It also allows equipment to have a chance to stabilize before starting a larger machine.
When a time delay relay is triggered, its coil energizes for a predetermined amount of time after the trigger signal has been applied. If the trigger signal is removed before the preset time elapses, then the relay coil is de-energized. If the trigger signal is applied again, then the relay re-energizes until the preset time elapses.
The time delay relay’s coil can be triggered by dry-contact control switches, such as float switches or limit switches, with voltage, or by an electronic input signal from a PLC or DCS. Its low side gate driver timing functions vary in terms of delay mode and parameter coordination.
Safe to Operate
Relays are essential components in various electrical and electronic systems, serving as versatile switches that open or close circuits. However, they are also sensitive and can be damaged if they are switched on or off too quickly. Adding a time delay relay to your system can help prevent this from happening.
This is because the relay contacts switch only after a certain amount of time passes. This helps ensure that the circuits don’t get activated too led transformer quickly or out of turn, minimizing the risk of damage or accidents.
The working principle behind a time delay relay is similar to that of any other control relay. It starts timing when the relay coil gets energized, but its contacts don’t start switching open or closed until it has a certain amount of time passed.
Once the desired time has elapsed, the relay coil is de-energized and its contacts are pulled back to their authentic position. This type of relay can be found in various applications, like repeat cycle timers used to control operating machinery or welding machines.
It is important to note that the timing of a time delay relay does not depend on the magnitude of its actuating current. This is because the lag between the instant that the actuating current crosses the pick-up level and when the relay contacts are finally closed is constant.
Versatile
There are a wide variety of applications for time delay relays. Often, they are used to turn on & off machinery in industrial settings so that it doesn’t consume too much energy or operate when not needed. In residential settings, they are also useful for operating lighting systems & other electrical devices based on a preset schedule.
Depending on the function, the timing circuit determines how long it takes for the output to switch from an open position to a closed one once power is applied to the coil. The delay can be fixed or adjustable, allowing for different timing periods to be set for various functions.
Some models are designed to accept a dry contact control switch trigger for a power-on function. Others are designed to use a control voltage for activation, starting the timing function & de-energizing the relay coil after the preset time has elapsed. All of our time relays include a range of different timing functions, time-setting methods and output configurations so that you can find the perfect product for your application.
To make the process of selecting a time delay relay even easier, we offer a selection of products that are easy to mount in cutouts in control panels and other enclosures for user-interfacing connections on the outside & socket/DIN connection for wiring inside. These models are ideal for installing in a panel where space is limited and need to fit with other relays, switches and components.