MCC Ethernet Network Cabling

Hi Guys,

I am working on a project where we will have a Smart MCC from Rockwell. We have over 50 motors, anyway we have ethernet capable motor starters (E3+) which will only be used for diagnostics and motor status. All control is hardwired. Anyway, in terms of ethernet cables, I was thinking of specifying Cat6 cables rather than Cat5e due to interference issues as these cables will be running through the MCC. What do you guys think? Is Cat6 overkill?

I would beg the question: Is Ethernet to a motor starter overkill?

Greg

Greg Dake said:

I would beg the question: Is Ethernet to a motor starter overkill?

Greg

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It's a requirement from the client. It's either Devicenet or Ethernet. We went ethernet as we won't be limited to the quantity of nodes.

Are you buying the MCC from rockwell? It should come prewired. Are you buying the ethernet MCC?

If so all the cat 5 cable is already run and is made special for that purpose by rockwell.

Have a look here http://ab.rockwellautomation.com/Mo...nters/NEMA-CENTERLINE-2100-with-IntelliCENTER

I don't know about your code rules but here the ethernet cables must be rated for 600 volts if running through the MCC.

Greg Dake said:

I would beg the question: Is Ethernet to a motor starter overkill?

Greg

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Nope. I think you should have ethernet prox sensors and such. Makes wiring and long term costs much better. Easier to troubleshoot and maintain also.

Less wires to get messed up my the night shift dude.

We need something like I/O link Here http://www.io-link.com/en/Technologie/IO-LinkOverview.php?thisID=46

But ethernet all the way down.

There's no significant difference in noise rejection between CAT5 and CAT6 at normal 100 Mb/s network speed with the sort of interference you'll find from ordinary AC drives and motor starters.

The shielding of the cable and the insulation of the cable are the critical parts.

The insulation especially: the only cable that will pass a code inspection in an MCC is the 600V jacketed Ethernet cable that A-B sells for these applications.

I've seen MCCs wired with ordinary 300V Category 5 cable before, but the owners of those MCCs were using an advanced electrical code compliance method called "hoping nobody notices".

Elmatador, are you using the 193-DNENCAT network bridges to get E3+ devices onto Ethernet, or are you using the E1 Plus ?

Those tiny Ethernet/DeviceNet bridges look really neat !

Ken Roach said:

Elmatador, are you using the 193-DNENCAT network bridges to get E3+ devices onto Ethernet, or are you using the E1 Plus ?

Those tiny Ethernet/DeviceNet bridges look really neat !

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Hi Ken,

Yes I will be using the 193-DNENCAT. It's basically a devicenet to ethernet bridge. It's a new release. I am always a little paranoid using newly released equipment. I took a look at the 600V Cat5e cable from Rockwell, I didn't even know this existed. Looks like Rockwell packages the Smart MCC with all the ethernet cables terminate, which would be 600V Cat5e. I would be connecting the smart MCC switches back to the main ethernet ring. I will spec out the Rockwell Cable for the main ethernet ring going in and out of the smart MCC's.

Thanks again for your insight. Much appreciated. I will let you know how these devicenet-ethernet bridges work out. I think its a pretty cool idea given the limitations of devicenet.

I researched at Cat 5e, 6, 6e cable differences recently. Wikipedia and such have good writeups. Cat 6 is much harder to work with since the cable is much thicker. For 100 Mbit/sec ethernet it offers no reliability advantage, so I would suggest rugged, higher voltage rated Cat 5e as others suggest. I think teflon jacketed plenum rated is the most rugged. I was looking at pushing the length. While they spec 100 m, most people suggest not exceeding 80 m. It also matters whether the conductors are solid (most) or stranded (patch cords). Stranded attenuates more. I ended up using fiber for our 101 m runs.

Try this:
http://www.belden.com/pdfs/Prodbull/NP314.pdf
best regards, steve