A direct on line (DOL) starter is one of the simplest methods for starting an electric motor. It functions by supplying a high level of current of voltage to each terminal in the motor. Compressors, fans, water pumps, and conveyor belts have all used this method of starting motors in the past.
This way of starting an engine is similar to using a defibrillator to restart a heart that has stopped beating. The straight on line starter kick starts the motor into life and gets the machinery up and running by providing a fast rush of maximum power to the engine. Use this type of starter only if your power source can handle the massive quantity of energy a DOL starter generates. The tremendous strain exerted on DOL starters as the engine begins might result in an extreme voltage drop for everything else connected to the line, therefore weak or already overstressed circuits are not the ideal means for supporting DOL starters.
Protecting the engine itself against overload is important when using this type of starter. The most common type of protection is a thermal overload relay, which prevents the engine from overheating from the voltage used during starting. There are two general types of thermal protection devices: bi-metallic strips and eutectic alloys. With bi-metallic strips, a dramatic increase in temperature causes a circuit to trip, stopping the power supply to the engine. Eutectic alloys, on the other hand, melt when too much current heats the metal, opening a circuit that stops the motor.
Direct on line starter methods
can use multiple circuits, giving the engine the capability to run in both clockwise and counterclockwise directions. This is a branched switch; only one direction or the other can be selected prior to engaging the direct on line starter in the engine. When the engine is started, depending on the position of the mechanical switch on the device that regulates the starting direction, one or the other circuit will be triggered. The engine will then begin to spin in the chosen direction.
Contact us today to learn what we have to offer or read more of our blogs