How to choose the right electromagnetic starter?

The electromagnetic starter is one of the most common devices intended for switching and controlling electrical loads. It is practically impossible to do without this device in the presence of pumps and motors. It is worth considering the issues associated with the selection of this equipment.

If you need an electromagnetic starter, you should first determine the manufacturer. If the company is problematic, you can determine the main parameters that are important to you. All devices of this category are interchangeable. Next, you need to determine the rated current of the starter. By this is meant the maximum current that can be passed through the contact group of the device. There is a classification of devices up to 16A, 25A, 40A and 63A. The electromagnetic starter can be designed for high currents, but it is not so often used. The larger the device, the larger the overall dimensions it has.

Then choose the degree of protection. If the electromagnetic starter is placed in a shield, it does not have a protective shell. For these purposes, the most suitable are small-sized models of the KMI series. An important factor of choice is the voltage of the coil. Typically, preference is given to models equipped with a 230 V part. If you take an analog with a 400 V coil, you can save one cable core. It is worth noting that usually the choice falls on non-reversible models. A reversing starter may be required, for example, to control a valve. It is made in the form of two non-reversible devices, which are connected together in a certain way.

When choosing an electromagnetic starter, you must decide whether there will be warning lights and control buttons on it. If it is installed in a shield, it should not have such attributes. You can additionally install the control buttons on the front panel door. These can be conventional START buttons having one NO contact, as well as a STOP button with an NC contact. At the control point, it is possible to establish a push button control station of the control unit type. If the starter is located outside the switchboard, it can be equipped with buttons built into the enclosure. The warning light indicates the appliance is on.

The next step is to select the thermal relay that is used to protect the motor. The starter, equipped with this part, has a larger mass and dimensions than without it.

Then you need to select additional contacts. In general, models with one additional contact used in the control scheme are used. If more complex projects are organized, one is not enough. In this case, it is appropriate to put an additional prefix with the necessary number of contacts.

Another important type of these devices is a thyristor starter. It is a contactless control unit, designed to control asynchronous three-phase motors at a distance.