- I t is always installed at a central location which may be near or far away
from motor or equipment, - A separate electrical room is essentially required for mounting the
integrated motor control centre which should be neat & clean and dust free.
Hence, it is not accessible to everyone and unauthorized people may not
approach the control centre. - It requires more time for installation, commissioning and trial run during
project execution stage. Lot of time is consumed (approx. 45 days per project)
in signal interfacing with DCS system.
i) The system needs less human interventions in case of fault rectification, over
load relay re-setting and maintenance. The system is safer than individual
starter etc.
j) Generally, this motor control system is used for process control where group
machines are operated in sequential mode and control at a time. like grinding
function in cement, furnace system, captive power plants, steel plants etc. All
t he sequential process is performed with integrated motor controlled centre.
k) The system is not capable to log event history of equipment for process
analysis and fault diagnosis of individual equipment / motor.
l) A conventional motor control centre consists of cabinet sections with power
bus and following electrical components
- Contactor
- Overload relays
- Fuses
- Circuit breaker
- Isolator
- Hardwire control cabling
1.3 Intelligent Motor Control Centre (MCC’S):
a) An intelligent motor control centre consists of cabinet sections with power
bus and provision for plug-in mounting of individual motor intelligent module.
Each motor controller/starter consisting of
- Main Switch (Switch Fuse Unit / Circuit Breaker)
- Power Contactor & Control Contactor
- Intelligent Module: Motor Management & Control Devices with a Profibus DP
interface - Local HMI
- I/O Communication through Profibus –DP plant DCS controller
b) An Intelligent Integrated motor control centre is a group of motor control
starters which is located near the process load centre. All the motor starters
are equipped with intelligent controllers, grouped in a single panel board and
i nstalled in an electrical room which is neat & clean, dust proof and preferably