Time Delay Relays

More Information about Time Delay Relays

Multi Function Time Delay Relays

Multi-function time delay relays are versatile devices that provide a variety of timing functions and delay options for controlling and monitoring electrical circuits. These relays can be used in a wide range of applications, including automation, process control, and equipment protection.

Multi-function time delay relays typically offer a range of timing functions, such as on-delay, off-delay, interval, and repeat-cycle, allowing them to meet a variety of timing needs. These relays can also offer adjustable time delays, allowing for greater flexibility in controlling circuits.

In addition to their timing functions, multi-function time delay relays can also offer additional features, such as selectable voltage inputs, digital displays, and multiple outputs. Some relays may also have programmable functions, allowing for more precise control and customization of the timing and delay functions.

Trigger Signals

A Trigger signal is an electrical signal that activates a time delay relay. This signal can come from a variety of sources, such as switches, sensors, or timers, and they are used to start the delay countdown.

When the trigger signal is received by the time delay relay, the relay begins the timing sequence. The duration of the delay is set by the timing mechanism in the relay, such as a resistor or capacitor, which controls the flow of current through the relay. Continuous cycling of the trigger signal at a rate faster than the preset time will cause the relay to remain energized.

Once the delay time has elapsed, the relay switches to a different state, such as turning on or off a motor or other device. This is achieved by using the current flow from the timing mechanism to activate the relay's switching mechanism, which changes the state of the circuit.

Delay on Release vs Delay on Operate

Delay on release and delay on operate are two types of time delay relay functions that introduce a delay before a circuit is deactivated or activated, respectively.

Delay on Release

Delay on release introduces a delayed interval before a circuit is deactivated or turned off. This function is useful in applications where it is important to maintain the operation of a circuit for a certain amount of time before it is shut down. For example, in an industrial process, it may be necessary to wait a certain amount of time before turning off a motor or other device to prevent damage to equipment or ensure that the process has completed.

Delay on Operate

Delay on operate introduces a delay before a circuit is activated or turned on. This function is useful in applications where it is important to provide a delay before starting a circuit to allow time for other components to be properly energized or to prevent damage to equipment. For example, in a power distribution system, a delay on operate time delay relay may be used to provide a delay before starting a large motor to prevent voltage dips that could damage other equipment.

FAQs

What is the input voltage and for timer relays?

The input voltage for timer relays can vary depending on the specific model and manufacturer of the relay. In general, timer relays can have input voltages ranging from as low as 12 volts to as high as 240 volts AC or DC.

Time Delay Relay Basics

ON Delay Relays 

When the coil in a normal relay is energized, the contacts are instantly closed, allowing the current to pass through. When the coil in an ON delay relay is energized, the contacts are delayed for a given period of time, before they close. A common use for an ON delay relay is to reduce the inrush current when powering on several devices at once. The ON delay relay can power on one device slightly later than another device. This can prevent too much inrush current that might blow a fuse or trip a breaker in an electrical circuit. 

OFF Delay Relays

OFF delay relays are similar to ON delay relays, however, the delay occurs when the coil is de-energized. When the coil is energized, the contacts instantly close. When the coil is de-energized, there is a delay before the contacts open. A common use for OFF delay relays is when using motors with fans. When the motor is turned off, an OFF delay relay allows the fan to continue cooling the motor for a given period of time before turning off.