? two signal types in same conduit

I maintain the security systems where i work which involve cctv camera systems, electric door strikes and burglar alarms. This equipment that was previously installed before I took this position operates on 12vdc and

24vdc/ac and > Hi, I'm running my class 2 wiring and 120V house wiring in separate

As long as there is no data combined with the 12 vdc you won't have any problems. Induction would reek havoc on most data signals when combined in the same conduit, especially unshielded.

Jack

That is largely a myth. We did a lot of testing in this area with Token Ring and Ethernet using Shielded Twisted pair T/R and unshielded Cat5 at a big corporation that sold Business Machines Internationally. It took an awful lot of high current noise to cause a very small number of recoverable errors. We were never able to introduce enough noise to significantly impact throughput in spite of tywrapping data cables with power, running them in the same conduit, looping them over flourecent ballasts and all the other "no nos" we could think of. The nature of twisted pair is that it rejects common mode interference. There are safety concerns about low voltage and line voltage in the same raceway but if you don't have a lot of spiky high current switching, your data is pretty safe.

I'll second that on the myth thing. I have been on projects where the electric closet with 480V switchgear shares a corner with the low voltage cabling. The data was UTP CAT 5 running either 16 MB Token Ring or 10 MB Ethernet. The cables, routers, switches, etc. were about 3 ft from the MSB. Perhaps it was the fiber runs to the computer room that saved the day.

I can tell you that Token-Ring was much less stable than Ethernet. At least with Ethernet, you could unplug the cable and the machine did not need rebooted (Windows NT 4.0).

Sincerely,

Donald L. Phillips, Jr., P.E. Worthington Engineering, Inc.

145 Greenglade Avenue Worthington, OH 43085-2264

snipped-for-privacy@worthingtonNSengineering.com (remove NS to use the address)

614.937.0463 voice 208.975.1011 fax

A lot of that has to do with the type of connectors you use. If they talked someone into RJ45s they were ignoring the fact that this is a "ring". The IBM wiring system connectors maintain the ring with the cable unplugged. There may also be some NT issues. We always ran something more robust.

I was referring to Ethernet being able to repair itself without rebooting when disconnecting the cable. A real PITA when you are trying to troubleshoot a computer since a PC takes more than 2 seconds to boot up.

Sincerely,

Donald L. Phillips, Jr., P.E. Worthington Engineering, Inc.

145 Greenglade Avenue Worthington, OH 43085-2264

snipped-for-privacy@worthingtonNSengineering.com (remove NS to use the address)

614.937.0463 voice 208.975.1011 fax