What I have is an Allen-Bradley MCC with Power Flex variable speed drives. I would like to communicate with these drives via 20-COM-E modules. This would require putting CAT-5 in the raceways with the motor leads. The motor leads are rate for 600V and the CAT-5 is only rated for 300V. I?ve done a bunch of searches and read a bunch of threads and I still can?t figure out if this is acceptable. Any help would be greatly appreciated.
Ethernet in a MCC raceway.
- Thread starter Montana
- Start date
- Status
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
I think 300.3(C)(1) would prohibit this. 2005 NEC
Last edited:
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Wait a minute. What is the voltage of the motors? 208 or 240 by chance?
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Never mind, 725.55 I think says no without a barrier.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
No older, 2005. Try 725.136(B) in 08 NEC
dbuckley
Senior Member
- Location
- Canterbury, New Zealand
Clipsal (a/k/a Schneider Electric, Square D etc) do special Cat5 rated for just this sort of use, in fetching pink.
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
091119-1922 EST
Montana:
Consider Ethernet to fiber and run the fiber with the high voltage. Even if you had high voltage Ethernet cable I would be concerned with noise problems.
See
http://www.neteon.net/Category/338-4/10-100-Fiber-Media-Converter?gclid=CK-7wJunmJ4CFUlo5QodWw1lmw
.
Montana:
Consider Ethernet to fiber and run the fiber with the high voltage. Even if you had high voltage Ethernet cable I would be concerned with noise problems.
See
http://www.neteon.net/Category/338-4/10-100-Fiber-Media-Converter?gclid=CK-7wJunmJ4CFUlo5QodWw1lmw
.
- Location
- Illinois
- Occupation
- retired electrician
Just put a length of flexible metal conduit in the MCC wireway and install the Ethernet in the flex.
I don't really think fiber is a real option here. The communications is being run to multiple buckets in the MCC. There is not likely enough space for the media converters and their power supplies.
I don't really think fiber is a real option here. The communications is being run to multiple buckets in the MCC. There is not likely enough space for the media converters and their power supplies.
- Location
- Illinois
- Occupation
- retired electrician
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
091120-0914 EST
Don:
Your information is useful because it relates a similar application.
Ethernet cables use twisted pairs. This greatly reduces magnetic coupling of noise to the balanced signal lines. They also use different pitches of the twist for the four different pairs to reduce crosstalk.
In crude uncontrolled experiments I have run with Ethernet communication with CAT-5 cable using a MIG welder as the noise source I found degradation of the signal, meaning retries, when the CAT-5 cable was in the range of about 3 to 4 ft of the MIG welder cables.
.
Don:
Your information is useful because it relates a similar application.
Ethernet cables use twisted pairs. This greatly reduces magnetic coupling of noise to the balanced signal lines. They also use different pitches of the twist for the four different pairs to reduce crosstalk.
In crude uncontrolled experiments I have run with Ethernet communication with CAT-5 cable using a MIG welder as the noise source I found degradation of the signal, meaning retries, when the CAT-5 cable was in the range of about 3 to 4 ft of the MIG welder cables.
.
weressl
Esteemed Member
NEC rules do not apply inside of a manufactured item.
Thanks to all of you. It?s nice to have a place to post a question to experts in the field. I can?t even imagine the years of experience that went into these replies. I can see this is a gray area that the NEC needs to address. Again thanks for all the replies.
Some where in Montana
Some where in Montana
weressl
Esteemed Member
Actually the NEC had already addressed it. It claims no authority inside electrical equipment.
- Status