A Motor Control Center (MCC) is by definition, a board that feeds, controls and protects circuits whose load essentially consists of motors and uses starters (contactors and relays) as main control components. It consists of an arrangement or combination of several starters grouped in a general cabinet or board, of the self-supported type, to protect a certain group of motors, which also allows to achieve through its internal wiring the automation to perform a certain process..1
Source: Of my authorship
The engines play a very important role in most industrial processes being those that act to maintain a variable in a given value, during my career I have had to install many types of systems but until now I had not had the opportunity to configure and automate an MCC, so I want to take the opportunity to share my experience with the community and when I get the desired results we will all celebrate together. To cover myself legally I want to make it clear that the information I intend to provide is based solely on the operation of the equipment without defining the process or disclose any other information belonging to the company for which I work or its client, in this sense I will only use the manufacturer's manuals and any information on the Internet that can serve as a reference respecting the parameters of copyright.
Starting of engines
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Before starting operation (permanent regime), electric motors go through a state that generates high current peaks (transient regime). The CCMs are in charge of taking the motor from a transient regime to a permanent regime, providing the adequate protections for the starting and correct operation of the motor in addition to providing disconnection protections in case of high temperatures, high current levels, phase failure and many other types of protections. They also allow automating the operation of the motors, monitoring and controlling remotely by means of a SCADA.
For this topic I want to address directly the motor control equipment TeSys-T from the manufacturer Schneider Electric, an intelligent motor management system. When associated with a short-circuit protection device and a contactor, the device provides complete monitoring, control and protection of electric motors..2
Among the most outstanding features we can mention that it provides primary protection, is an intelligent relay that can monitor electrical variables to provide excellent protection, can handle advanced communication protocols such as Modbus, Ethernet and others. It has an LTMCU unit that allows you to adjust the parameters to monitor, is easy to configure through an HMI device or through a PC using PowerSuit Software. 3
Source: Of my authorship
In the image we can see the cabinet of a MCC, this was one of the ones I had to work today and inside we can see the device TeSys-T already wired and connected. This system has local operation by push buttons, remote by contacts through a DCS or remote by one of its advanced communication protocols that in my case is Modbus to communicate with a PLC RsLogix 5572 Rockwell Automation.
Before going on I think it is necessary at this point to define that Modbus is an industrial communication protocol for the transmission of information between different electronic equipment connected to the same bus. Many field devices use it to communicate with PLC's and SCADA's. 4 Within the protocol we can find MODBUS RTU and ModBus/TCP, in our case we will use the second that is compatible with our device TeSys T and the devices associated to the automation that we want to establish.
Source: Of my authorship
Our network consists of several TeSys-T arranged in a network configured as a star through which all devices are connected to the same concentrator communicating through Modbus/TCP, then a cable will guide the communication to a module MVI56E-MNET Prosoft Technology which is responsible for interpreting the communication and maintain the sending and receiving commands between the PLC and TeSys-T equipment to maintain the automated process.
Each TeSys-T device must be configured within the network to be identified in the communication process, the configuration will be done through the PowerSuit software through a special Modbus RJ45 cable.
Source: Of my authorship
I'm not writing about something I've already done but about something I'm doing, it will take time to develop the system to its functional point so I think it will take me several articles to develop and describe all the devices along with their configurations, for now I leave this post and remain attentive to questions in the comments section. Greetings.
References
[1]MCC
[2]TeSys T
[3]TeSys T
[4]Modbus
