Motion System Design

FAQs about NFPA-79

Does UL dictate what cables are installed in the field?

No. They control the construction and testing requirements of cables, ensuring that all electrical, physical, and environmental parameters are in compliance.

Who controls the cables that are being installed?

National Electrical Code regulations cited by the authority having jurisdiction in the area, generally the local electrical inspector.

Must a machine meet NFPA-79 standards?

Depending on your application and if your product is being installed in a building, yes. If you're not sure of the machine's final destination, it's advisable to comply with NFPA-79 for safety and to avoid unnecessary litigation.

If the cable is UL listed, can it be used on a machine?

Not necessarily. Some machines use listed cordage incorrectly, as these cable types are only intended for temporary applications. Even if your cables have a UL listing, the minimum stranding count required by NFPA-79 must be met.

Is NFPA-79 a law?

No. It is a standard used by the machinery industry in the U.S. as the benchmark in safety compliance.

Is the industry going to become standardized with the 2007 edition of NFPA-79?

In the long run, yes, because of issues surrounding liability and safety. No one will want to risk liability by purchasing a machine that does not comply.

If my cable is MTW, can it be run into building infrastructure?

No. It must be dual marked with another UL listing such as “TC,” which indicates the cable complies with a high flammability rating. MTW requirements mandate that a cable only meet a minimal type of flame test, VW-1.

May cable be left exposed when going from machine to cable tray?

No, unless the cable has an Exposed Run approval such as TC-ER.

Are MTW cables required to be oil resistant?

Yes, all MTW cable must meet the requirements of the Oil Res I test due to the demanding conditions associated with industrial machine environments.

What's unique about the MTW approval?

The approval requires that the cable is flexible, but also has a high degree of mechanical durability so it can perform under the challenging conditions surrounding manufacturing and industrial machinery.

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