Cords and cables may include a Type Letter suffix that corresponds to the UL classification for the intended application and specifies certain wire features, such as heavy-duty construction, oil resistance, indoor or outdoor use, and others. Some common suffixes are:
- S: Standard Service Grade
- SJ: Junior Hard Service Grade
- E: Elastomer (Rubber Material)
- T: Thermoplastic
- O: Oil-resistant outside jacket
- OO: Oil-resistant insulation and outside jacket
- W: Approved for outdoor use
For a complete list of suffixes, refer to table 400.4 in Errata NEC.doc (nfpa.org).
Relevant Types
C, E, EO, ET, ETLB, ETP, ETT, G, G-GC, HPD, HPN, HSJ, HSJO, HSJOO, NISP-1, NISP-2, NISPE-1, NISPE-2, NISPT-1, NISPT-2, PD, PPE, S, SC, SCE, SCT, SE, SEW, SEO, SEOW, SEOO, SEOOW, SJ, SJE, SJEW, SJEO, SJEOW, SJEOO, SJEOOW, SJO, SJOW, SJOO, SJOOW, SJT, SJTW, SJTO, SJTOW, SJTOO, SJTOOW, SO, SOW, SOO, SOOW, SP-1, SP-2, SP-3, SPE-1, SPE-2, SPE-3, SPT-1, SPT-1W, SPT-2, SPT-2W, SPT-3, SRD, SRDE, SRDT, ST, STW, STO, STOW, STOO, STOOW, SV, SVE, SVEO, SVEOO, SVT, SVTO, SVTOO, TPT, TST, W, EV, EVJ, EVE, EVJE, EVT, EVJT,