Motor Control Centres (MCC) - Selection And Benefits

Motor Control Centres (MCC)

Motor control centers are having following electrical equipment's :

1. Main bus bar
2. Earthing bus bar
3. Incoming busbar circuit breaker
4. Outgoing switching devices
5. Fuses
6. Safety interlocking devices
7. Protective relays
8. Control and monitoring devices
9. Communication or network interfacing devices
10. Terminal compartment

Motor Control Centres are having following features used to reduce the possibility of are flesh incidents and injuries in motor control centres :

Component Rejection Features - 

it ensures compatible components are used as a system.

Voltage Test Points -

it provides point of testing for presence of voltage outside the unit

Correctly applied torque to electrical joint connections

IP20 - 

Finger Safe - 

it prevent exposure of live parts

External Voltage Indication

Proper Component Selection - 

it ensure property rated components used in the system.

Labyrinth Bus Shutters - 

Provide isolation of bus with shutters wherever possible

Remote Racking Mechanism - 

Provide capability of racking the unit in/out outside of the are-flash boundary

Correct Instruction Materials - 

Provide correct and adequate instruction material

Use Current Limiting Interrupters - 

Fuses and High interrupting breaker shall be used .

Selection Criteria For Motor Control Centres

1. Electrical shock resistance compartments and enclosures
2. Proper physical access to human operators
3. Smaller and simpler construction
4. Rigid barriers
5. Separation of bus bar and terminations
6. Cost and economic factors
7. Single and duplicate bus bar system
8. Safety interlocking devices (both mechanical and electrical)
9. Proper control and indication devices to avoid human operator error.
10. Good Man Machine Interface.
11. Availability of battery or uninterruptible power supply (UPS).
12. Availability of under voltage relay
13. Availability of serial communication network equipment
14. Electromagnetic interference
15. Microprocessor based system for better control
16. Arc flash hazard preventive assembly which can protection system.

Benefits Of Motor Control Centres

1. Equipment size gets reduced resulting lower civil, capital and installation costs.
2. Due to simple design time required for design, manufacture, installation commissioning get reduced.
3. By carrying out preventative maintenance working life can be increased.
4. Reduced maintenance cost.
5. Higher working personnel safety due to computerized control.