Intelligent MCC's

[GDL90958]

All,

I am after a bit of advice utlising 'intelligent' MMC's - basically does anyone have any experience of such devices and what the manufacturers mean by 'intelligent'?

am i correct in thinking that these devices can be bought as an integral part of the MCC enclosure and they have various self diagnostic parameters - overload, ground fault etc? If so would the switchgear cubicles have a screen where all motor info is displayed? and then we choose which info is passed back to the integrated control system for process control purposes.

any thoughts!

G

 

[gordonl]

We've installed a couple of intelligent MCC's. Basically instead of thermal overloads an electronic motor protector is used which protects the motor, as well as control, and annunciation. The PLC system then communicates with the motor protectors for control/alarms/metering. I haven't seen a system where an HMI is built into the MCC, but it could prbably be done.

The advantages are decreased field wiring (only communication to PLC), motor information on motor condition and operation, usually improved motor protection, less PLC IO.

Disadvantage - more work in PLC programming, more work in MCC setup and commisioning.

The protection you receive depends totally on the electronic motor protector used, which varies widely.

 

[jerryb]

Allen-Bradley markets their "Intellicenter" brand of smart MCCs. Instead of individual control wiring to each bucket, it uses DevicNet to connect each bucket to a PLC. They provide software that runs on a PC that is used to interact with the MCC. As a start you should contact your Allen-Bradley distributor and ask for Pub 2100-BR001A-US-P.

One word of caution though. In my last project, we were involved in the specification and selection of 14 MCCs. Allen-Bradley priced the Intellicenter at a premium significantly higher than the price for the itemized parts and labor. Check their pricing carefully. If a number doesn't look right, challenge it.