Q&A Forums

Low voltage wiring Post New Topic | Post Reply

Author Comments
bob brown
Posted: Sep 24, 2008 06:15 PM
Low voltage wiring
Will spray foam melt the shielding on low voltage runs? Heard from a home owner who had all his low voltage cable melt form the heat of the foam (closed-cell)
mason
Posted: Sep 25, 2008 08:16 AM
Yes, When spraying closed cell SPF temperatures within the rising foam can exceed 250 degrees F, (which is the temperature that the insulation on low voltage wiring can begin to melt.)

Exothermic heat build up is greater with thicker lifts. So, when spraying over low voltage wiring, spray in 1/2 inch lifts initially until the wire is encapsulated with the foam. Be sure to wait 10 minutes or more (ask your supplier for specific times with their foam) before applying more foam between lifts.
bob brown
Posted: Sep 25, 2008 02:25 PM
One more - how about open-cell foam .5 lb? Does it heat up like the closed-cell?

thx!
Jim Coler
Posted: Sep 26, 2008 06:55 AM
It depends on the open cell manufacturer, but most open cells allow for the heat to discipate a quicker and the ones I've used reach about 150-160F.

You need to login to reply to this topic. Please click here to login.