With the networked security systems of smart, connected homes, homeowners can remotely control the system, see when their garage doors open and close and adjust any cameras they have set up. Key features of these systems are ease of installation, configuration and use. For industrial automation applications, users can look for similar features in a motor control center (MCC). With MCCs, plant managers can centralize their controls for easier management and access, while operators and maintenance staff can individually maintain each connected motor. However, MCCs are used in voltage applications that are typically much higher than those in a home (200 to 600 volts of alternating current), and that voltage can pose risks to operator safety and lead to more “inconvenient” use.
When selecting an MCC, plant managers should look for complete MCC solutions that offer three technologies that greatly improve ease of use and operator safety: remote monitoring, arc flash-resistant design and withdraw with door-closed capability.
Remote monitoring & access
The safest way to interact with an MCC is remotely away from voltage and power. With remote monitoring and access, operators can interact with the MCC while removing all physical risk.
The MCC should be fully networked with the network information configured out of the box. This visibility into the MCC allows operators to monitor the MCC for energy usage or operating conditions, receive notifications and diagnose an issue or fault, and make programming changes from the safety of the control room.
Arc-resistant design
Remote monitoring is the ideal situation. However, on a given workday, an operator will likely need to be on the plant floor in relatively close proximity to the MCC. If an arc flash event occurs, being close to an MCC can pose the risk of serious injury.
With an arc-resistant design, the MCC is more likely to limit the duration of the current during an arc; contain and redirect the heat, gases and debris created from an arc flash event; and reduce risk to personnel. This helps improve operator safety and could reduce the need for extra protective personnel equipment, which can be difficult to maneuver and work in.
Withdraw with door closed
Occasionally, an operator will need to perform maintenance inside the MCC and open a unit door. Standard MCC design allows staff to reduce the voltage in the specific unit, but the voltage is still present. Alternatively, staff can go through a lengthy lock-out, tag-out procedure and shut down the entire MCC.
An MCC designed with the ability to withdraw with the door closed helps protect from electrical hazards and provides a safer interaction with the MCC. When operators work with a unit, they can disconnect the voltage before opening the door, which removes all voltage within the unit and helps remove the risk of live voltage contact.
Users should still verify that all voltage is absent from the unit before removing any protective gear and opening the unit door, but the capability to withdraw with the door closed allows operators to work on the unit more safely.
Each of these three technologies on its own helps improve ease of use and operator safety. Selecting a complete MCC solution that offers all three allows plant managers to have more insights into plant production and provide a safer work environment for employees.
Ryne Montemurro is product marketing manager for Rockwell Automation and is responsible for managing the CENTERLINE 2100, NEMA Motor Control Center products and the marketing team. He can be reached at [email protected].
