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Wire & Cable Glossary

What do the 'M' and 'C' in MC cable mean? What does XLPE cable stand for? Why is it called SOOW cable? Answers to these questions and more!scientists

The world of wire and cable has a language of its own, and even those with experience need a translator from time to time. Your old pal Willie knows this to be true, so I’ve compiled a cheat sheet on wire and cable nomenclature for you to reference.

First, we have a list of individual descriptors, each either made up of one or two letters. These can define what the cable is used for, what it’s made of, or what the cable can withstand––like heat resistance or voltage ratings. Often, a cable’s name will be some combination of two or more of the descriptors below.

The Components of Wire & Cable Nomenclature

E: thermoplastic elastomer
FF: flexible fixture
H: heat-resistant 75ºC
HH: high heat-resistant 90ºC
J: junior service, rated to 300 volts

[caption id="attachment_2154" align="alignright" width="250"]non-metallic building wire NM-B: non-metallic building wire.[/caption]

ML: motor lead wire
N: nylon coating
NM: non-metallic
O: oil-resistant jacket
OO: oil-resistant jacket and insulation
P: polyethylene coating
PV: photovoltaic
R: rubber-insulated
S: service cord
SE: service entrance
SR: silicone rubber insulation

[caption id="attachment_2155" align="alignright" width="250"]seoow cable SEOOW: Service cable w/ thermoplastic Elastomer, Oil-resistant jacket & Oil-resistant insulation, Weather-resistant[/caption]

T: thermoplastic
V: vinyl coating
VW: vertical wire
W: weather-resistant / water-resistant
W/G: with ground
X: cross-linked

If you’re looking for an explanation of a specific cable’s nomenclature, below is a list of popular cable types and what their names signify.

Wire & Cable Names and Explanations

DLO: Diesel Locomotive cable
HCF: Health Care Facilities wire
MC: Metal-Clad cable
MTW: Machine Tool Wire
NM-B: Non-Metallic Building wire
RHH: Rubber-insulated High Heat-resistant cable
RHW: Rubber-insulated Heat- Water-resistant cable
SEOOW: Service cable w/ thermoplastic Elastomer, Oil-resistant jacket & Oil-resistant insulation, Weather-resistant
SER: Service Entrance cable with Reinforcement tape
SIS: Switchboard wire
SJEOOW: Service cable Junior (300V) w/ thermoplastic Elastomer, Oil-resistant jacket & Oil-resistant insulation, Weather-resistant
SJOOW: Service cable Junior (300V) w/ Oil-resistant jacket & Oil-resistant insulation, Weather-resistant
SOOW: Service cable w/ Oil-resistant jacket & Oil-resistant insulation, Weather-resistant
SRML: Silicone-Rubber insulated Motor Lead wire
STO: Service cable w/ Thermoplastic Oil-resistant jacket
TFFN: Thermoplastic Flexible Fixture Nylon wire
TGGT: Teflon-Glass-Glass-Teflon; Teflon wrapped w/ Teflon-impregnated, Glass outer braid
THHN: Thermoplastic High Heat-resistant Nylon wire
THWN: Thermoplastic High Water-resistant Nylon wire
UF-B: Underground Feeder and Branch circuit
USE-2: Underground Service Entrance cable
VNTC: Vinyl Nylon Tray Cable
XHHW: Cross-linked High Heat- and Water-resistant cable
XLP or XLPE: Cross-Linked Polyethylene

The nomenclature of wire and cable is not a fully uniform system, and it can be a little confusing. (For instance, not every instance of the letter “W” denotes a weather-resistant cable—MTW stands for machine tool wire.) Hopefully, this list can be of use the next time you’re curious about what your wire or cable’s label means.