![]() Also called normally-closed, on-delay relays. Abbreviated “NCTO”, these relays close immediately upon coil de-energization and open only if the coil is continuously energized for the time duration period. Also called normally-open, off delay relays. Abbreviated “NOTO”, these relays close immediately upon coil energization and open after the coil has been de-energized for the time duration period. Also called normally-open, on-delay relays. ![]() Abbreviated “NOTC”, these relays open immediately upon coil de-energization and close only if the coil is continuously energized for the time duration period. Time delay relays are built in these four basic modes of contact operation:.For this reason, there is usually a time-delay circuit arranged on each conveyor to give it adequate time to attain full belt speed before the next conveyor belt feeding it is started. In order to get large belts up to full speed, some time may be needed (especially if soft-start motor controls are used). Conveyor belt sequence delay: when multiple conveyor belts are arranged to transport material, the conveyor belts must be started in reverse sequence (the last one first and the first one last) so that material doesn’t get piled on to a stopped or slow-moving conveyor.After a prescribed time delay (provided by a time-delay relay), full power is applied. Motor soft-start delay control: Instead of starting large electric motors by switching full power from a dead stop condition, reduced voltage can be switched for a “softer” start and less inrush current.A time-delay relay provides the furnace control logic with this necessary time element. Furnace safety purge control: Before a combustion-type furnace can be safely lit, the air fan must be run for a specified amount of time to “purge” the furnace chamber of any potentially flammable or explosive vapors.Time-delay relays help sequence these events for proper start-up of the engine. To properly start a large engine, certain auxiliary devices must be started first and allowed some brief time to stabilize (fuel pumps, pre-lubrication oil pumps) before the engine’s starter motor is energized. Engine auto start control: Engines that are used to power emergency generators are often equipped with “autostart” controls that allow for automatic startup if the main electric power fails. ![]() Flashing light control (time on, time off): two time-delay relays are used in conjunction with one another to provide a constant-frequency on/off pulsing of contacts for sending intermittent power to a lamp.Time-delay relays are very important for use in industrial control logic circuits. Time-Delay Relays Uses in Industrial Control Logic Circuits
0 Comments
Leave a Reply. |