SPT-3

4 coding systems recognise this code

NEC / UL (USA)

Symbol	Meaning
`S`	Service cord
`P`	Parallel (zip) construction
`T`	Thermoplastic (PVC)
`-3`	Insulation thickness class 3 (UNVERIFIED)
`SPT-3`	Parallel thermoplastic lamp cord, insulation class 3. 300 V, 60 to 105 C (UNVERIFIED). UL 62; NEC Table 400.4

NEC 400

Symbol	Meaning
`S`	Extra Hard Usage Flexible Cord
`P`	Parallel Conductor Cord
`T`	Thermoplastic Insulation And Jacket
`-3`	Insulation Thickness (Thickest) / 0.060" - 0.110" (1.524 2.794 Mm)

NEC 402

Symbol	Meaning
`S`	Silicone Rubber
`P`	Perfluor (Ethylene Propylene - FEP - Teflon)
`T`	Thermoplastic Insulation
`-3`	Insulation Thickness (Thickest) / 0.060" - 0.110" (1.524 2.794 Mm)

IEEE 1580

Symbol	Meaning
`S`	Single Conductor Distribution, 3 kemil
`P`	Cross Linked Polyolefin (XLPO)
`T`	Polyvynil Chloride (PVC)