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Did you Know?
The Best Kept Secrets in the Wire Distribution Industry

This section provides factual information about codes approved products and systems that may shock you, but unfortunately are all true.

1. The Standard that governs Wire & Cable for use in Plenums allows plastic coated cable to ignite immediately upon exposure to flame and to produce unlimited amounts of toxic smoke. Plenum rated cable is Code Approved but is it safe?

2. Did you know that unlimited amounts of non-plenum rated telecom cable are permitted in service entry plenums exterior to the lightening protection? What if lightening instantly ignited this cable?

3. What is the current limit in NFPA Standards on combustible plastic permitted in Ceiling or Access Floor Plenums? Answer: no limit

4. Abandoned, plenum rated telecom cable is no longer permitted in Ceiling or Access Floors because of its huge fuel load. However active cable made with the same plastic coverings is still permitted in unlimited amounts. Makes sense doesn't it!

5. Most "fire retardant" plenum rated cable (CMP cable) looses fire retardancy with age due to the slitting of their fire retardant jackets. But since there is no code restriction on ignition of plastics used in plenum spaces it really doesn't matter (unless there's a fire, of course).

6. The latest National Electrical Code (NFPA-70) revision requires removal of abandoned telecom cables from plenums because of its dangerous fuel load. But if you leave the connector on each end or tag it for future use it becomes fire safe and can remain in the plenum. (Believe it or not!)

7. Poke-thru electrical outlets are fire rated for up to 4 hr. ratings. However, in a fire, toxic smoke will penetrate most of these outlets in seconds and in large amounts. Got a poke-thru outlet under your desk?

8. The new UL Scrub Water Exclusion Test for electrical floor boxes requires a watertight cover. But it only excludes water if no wires or cables are plugged into the box. So, before scrubbing the carpet, make sure the janitor has un-plugged all the computers, printers and other office equipment and closed the cover tightly! (Duct tape would do an equally good job)

9. Non-metallic surface raceway (AKA plastic raceway) is becoming more and more popular. ...but is it safe?

Here's the required UL fire test:

25 seconds of flame in 5-second increments alternated with 5 seconds of no flame.

Here's the failure criteria:

1. Sample continues to burn for 10 seconds after flame removal.
2. Molten dripping plastic ignites cotton waste below the sample.
3. The sample is completely consumed by the fire. (If you can't find the sample after the test, it's a failure!)

10. Power and telecom cables inside a non-metallic (plastic) surface raceway do not need to be fire retardant or enclosed in metal conduit, ordinary combustible plastic is OK.

If it weren't for the toxic smoke, plastic raceways would be excellent for heating your lunch!

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