USE-2 600V ALUMINUM UD: KEEP IT OUTSIDE
UL listing doesn't mean a cable can enter a building. Standard USE-2 600V UD is approved for outside use only.
- Published in Southwire's T&D Update newsletter in February 1998
- Reprint permission granted
When you Shop for 600V secondary distribution products with aluminum conductors, keep you application in mind. In the utility business, the standard for 600V UD cable is a UL-listed USE-2 rated product with a 1350 aluminum conductor. The Aluminum Association 1350 designation specifies that the metal is electrical conductor-grade unalloyed aluminum.
USE-2 is Rated for Outside Applications
"USE-2 gives you a 600V service distribution product you can use either direct-buried or in conduit outside buildings," says Dave Mercier, applications engineering manager. The USE-2 rating allows 90C operation in wet or dry locations.
Southwire supplies USE-2 rated 600V UD cable with a 1350 conductor for utility distribution applications. Southwire makes USE-2 in single-conductor and multi-conductor duplex, triple and quadraplex variations. Single-conductor sizes range from AWG 6 to 1,000kcmil. The multiconductor versions are available in selected sizes. Conductors are insulated with Southwire's VIP® crosslinked polyethylene compound.
The National Electric Code (NEC) does not require USE-2 cable to be fire retardant. "Because it isn't required to be fire retardant, USE-2 isn't allowed to penetrate a building," Mercier says. "Utility engineers deal primarily with outside applications, so that's not usually an issue."
To Penetrate Buildings, Use Triple-Rated Cable
"If you do need to run 600V UD cable into a building, expect to spend a little more for your cable," Mercier says. The UL-listed cables entering a building must be flame retardant. Conductors must be copper or an 8000-series aluminum alloy. Those options all add to cable cost. Southwire manufacturers a UL-listed USE-2/RHH/RHW-2 product that meets those requirements.
"You may not want to use the triple-rated cable as a blanket for your standard 600V cable because of the cost," Mercier says. "But specifiers should know about the option." |
