Transformed into ANSI Standards

Medium-voltage cable buyers encountering familiar cable requirements transformed into ANSI standards

Specifying Cable? New Numbers To Know
Medium-voltage cable buyers encountering familiar cable requirements transformed into ANSI standards

If you're shopping for medium-voltage cable, some very familiar requirements are about to change - and you'll need to learn some new numbers. What's up? The utility industry's long-standing requirements for cross-linked polyethylene (XLP) and ethylene propylene rubber (EPR) MV cable insulations have been combined into a single document that has been accepted by the American National Standards Institute.

"Utility buyers are used to calling out ICEA S-66-524 and AEIC CS5 when they order XLP insulation, and ICEA S-68-516 and AEIC CS6 for EPR cables," says Nick Ware, technical director for Southwire's Energy Division. "Now buyers are going to be referencing some different document numbers for essentially the same requirements."

Joint task force drafted new standards.
What's happening is the result of a cooperative effort between the Association of Edison Illuminating Companies (AEIC) and the Insulated Cable Engineers Associations (ICEA) that's been going on for several years.

In the past, the standards for XLP insulated cables and EPR-insulated MV cables were separate ICEA documents - S-524 and S-516. Those documents had separate AEIC supplements - CS5 and CS6 - that added utility-specific requirements to the generic MV standards.

In the new MV standards scheme, the requirements are very similar, but they're organized by cable architecture. There is a single document - ANSI/ICEA S-94-649 - for all concentric neutral cables, whether they’re insulated with XLP or EPR. Another document - ANSI/ICEA S-97-682 - covers XLP and EPR cables that use copper tape shields, longitudinally corrugated tape, or drain wire shields. Both of these documents are extended by a single AEIC supplement, AEIC CS8. (See table.)

ANSI acceptance adds authority.
"Besides organizing the requirements differently, the new standards have the authority of being ANSI standards," Ware says. "That brings MV cable specifications in line with the rest of the industry's hardware. We've had ANSI standards for switchgear and transformers for years, but there was no ANSI standard for the cables."

Some overall diameters are different.
One difference in the new standards is that the overall cable diameters in the new ANSI documents are slightly smaller than the equivalent diameters in AEIC CS5. The larger, CS5 diameters are still included in AEIC CS8.

"The ANSI standard diameters are simply the sum of all the required layers," says Ware. "It's primarily an issue of mechanical fit in cable accessories that might be right at the limits in the older diameter specifications. You have to check your accessories to see if they will accept the smaller diameters. In most of the applications, it's not a problem."

Ware concludes, "Overall, we feel it's in the best interest of the utility industry to move to the new standards. We're encouraging our customers to include them in the purchasing process."

ANSI Standards For MV Cable Old Standard AEIC CSS	New Standard AEIC CS8

ICEA S-66-524/NEMA WC7 Polyethylene concentric neutral cables	ANSI/ICEA S-94-649 All concentric neutral cables

ICEA S-66-524/NEMA WC7 Polyethylene copper tape shield, LCT, or drain wire shielded cables	ANSI/ICEA S-97-682 All copper tape shield, LCT, or drain wire shielded cables

AEIC CS6	AEIC CS8

ICEA S-68-516/NEMA WC8 Ethylene Propylene Rubber concentric neutral cables	ANSI/ICEA S-94-649 All concentric neutral cables

ICEA S-68-516/NEMA WC8 Ethylene Propylene Rubber copper tape shield, LCT, or drain wire shielded cables	ANSI/ICEA S-97-682 All copper tape shield, LCT, or drain wire shielded cables

New MV cable standards are organized by construction architecture and have the authority of ANSI acceptance