SIS
SIS switchboard wire combines stranded tinned copper conductors with cross-linked polyethylene (XLPE) insulation for switchboards, switchgear and electrical distribution equipment. The 600V, 90°C SIS construction provides a thermoset-insulated option for panel connections where the wire carries the required switchboard marking. Gauge and color choices support circuit identification, equipment layout and termination requirements during fabrication or replacement work. Additional AWM markings may establish separate ratings for other uses. This wire family serves panel builders, electrical equipment manufacturers and industrial maintenance teams working to an approved wiring specification.
Available Sizes
10 sizes in stock, cut to length. Click a size to start your quote.
Construction & Ratings
Conductor
Insulation
Voltage Rating
Temperature Rating
Available Insulation Colors
11 color options in stock. Custom striping and ID print available on request.
SIS Part Numbers
110 SIS part numbers stocked or sourced by Mid America Wire & Cable. Open a part number for its details, or request a quote for the size and length you need.
| Part Number | Description | Unit Weight (lbs) |
|---|---|---|
| 50C-011064-08 | 1/0( 1064) SIS Tinned Copper 600 Volt Gray | 0.33 |
| 50C-01133-0 | 1(133) SIS Black | 0.33 |
| 50C-01259-09 | 1(259) SIS XLP Tinned Copper 600 Volt White | 0.33 |
| 50C-02133-0 | 2(133) SIS 600 Volt Black | 0.39 |
| 50C-02133-05 | 2(133) SIS 600 Volt Green | 0.24 |
| 50C-02133-08 | 2 (133) XLP SIS Tinned Copper 90C 600 Volt Gray | 0.24 |
| 50C-021330-08 | 2/0 (1330) SIS Tinned Copper 600 Volt VW-1 Gray | 0.49 |
| 50C-031672-08 | 3/0(1672) SIS VW1 Gray | 0.62 |
| 50C-04133-0 | 4(133) XLP SIS UL3196 Tinned Copper 90C 600 Volt Black | 0.16 |
| 50C-04133-05 | 4(133) SIS Green | 0.16 |
| 50C-04133-08 | 4(133) SIS Gray | 0.16 |
| 50C-06133-0 | 6(133) XLP SIS UL3196 Tinned Copper 90C 600 Volt VW-1 Black | 0.10 |
| 50C-06133-02 | 6(133) XLP SIS UL3196 Tinned Copper 90C 600 Volt VW-1 Red | 0.10 |
| 50C-06133-05 | 6(133) XLP SIS Tinned Copper 90C 600 Volt Green | 0.10 |
| 50C-06133-06 | 6(133) XLP SIS UL3196 Tinned Copper 90C 600 Volt VW-1 Blue | 0.10 |
| 50C-08133-0 | 8(133) XLP SIS UL3195 Tinned Copper 90C 600 Volt VW-1 Black | 0.07 |
| 50C-08133-01 | 8(133) XLP SIS UL3195 Tinned Copper 600 Volt Brown | 0.07 |
| 50C-08133-02 | 8(133) XLP SIS UL3195 Tinned Copper 90C 600 Volt Red | 0.07 |
| 50c-08133-03 | 8(133) XLP SIS UL3195 Tinned Copper 600 Volt Orange | 0.07 |
| 50C-08133-04 | 8(133) XLP SIS UL3195 Tinned Copper 600 Volt Yellow | 0.07 |
| 50C-08133-05 | 8(133) XLP SIS UL3195 Tinned Copper 90C 600 Volt Green | 0.07 |
| 50C-08133-08 | 8(133) XLP SIS UL3195 Tinned Copper 600 Volt Gray | 0.07 |
| 50C-08133-09 | 8(133) UL3195 Tinned Copper 90C 600 Volt White | 0.07 |
| 50C-10105-0 | 10(105) XLP SIS Tinned Copper 125C 600 Volt Black | 0.04 |
| 50C-10105-01 | 10(105) SIS Tinned Copper 600 Volt Brown | 0.04 |
| 50C-10105-02 | 10(105) XLP SIS Tinned Copper 600 Volt Red | 0.04 |
| 50C-10105-03 | 10(105) SIS tinned Copper 600 Volt Orange | 0.04 |
| 50C-10105-04 | 10(105) SIS Tinned Copper 600 Volt Yellow | 0.04 |
| 50C-10105-05 | 10(105) XLP SIS Tinned Copper 125C 600 Volt Green | 0.04 |
| 50C-10105-06 | 10(105) XLP SIS Tinned Copper 125C 600 Volt Blue | 0.04 |
| 50C-10105-08 | 10(105) XLP SIS Tinned Copper 125C 600 Volt Gray | 0.04 |
| 50C-10105-09 | 10(105) XLP SIS Tinned Copper 125C 600 Volt White | 0.04 |
| 50C-1265-0 | 12(65) XLPE SIS Tinned Copper 125C 600 Volt CSA RW90 Black | 0.03 |
| 50C-1265-02 | 12(65) XLP SIS Tinned Copper 125C 600 Volt Red | 0.03 |
| 50C-1265-03 | 12(65) UL3173 Orange | 0.03 |
| 50C-1265-05 | 12(65) XLP SIS Tinned Copper 125C 600 Volt Green | 0.03 |
| 50C-1265-06 | 12(65) XLP SIS Tinned Copper 125C 600 Volt Blue | 0.03 |
| 50C-1265-07 | 12(65) XLP SIS Tinned Copper 125C 600 Volt Purple | 0.03 |
| 50C-1265-08 | 12(65) XLP SIS Tinned Copper 125C 600 Volt Gray | 0.03 |
| 50C-1265-09 | 12(65) XLP SIS Tinned Copper 125C 600 Volt White | 0.03 |
| 50C-1265-69 | 12(65) XLP SIS Tinned Copper 125C 600 Volt Blue with White Stripe | |
| 50C-1265-96 | 12(65) Ul3173 SIS White with Blue Stripe | 0.03 |
| 50C-1441-0 | 14(41) XLP SIS UL3173 Tinned Copper 125C 600 Volt Black | 0.02 |
| 50C-1441-01 | 14(41) XLP SIS UL3173 Tinned Copper 125C 600 Volt Brown | 0.02 |
| 50C-1441-02 | 14(41) XLP SIS UL3173 Tinned Copper 125C 600 Volt Red | 0.02 |
| 50C-1441-03 | 14(41) XLP SIS UL3173 Tinned Copper 90C 600 Volt Orange | 0.02 |
| 50C-1441-04 | 14(41) XLP SIS UL3173 Tinned Copper 90C 600 Volt Yellow | 0.02 |
| 50C-1441-05 | 14(41) XLP SIS UL3173 Tinned Copper 125C 600 Volt VW-1 Green | 0.02 |
| 50C-1441-06 | 14(41) XLP SIS Tinned Copper 90C 600 Volt Blue | 0.02 |
| 50C-1441-08 | 14(41) XLP SIS Tinned Copper 125C 600 Volt Gray | 0.02 |
| 50C-1441-09 | 14(41) XLP SIS UL3173 Tinned Copper 125C 600 Volt White | 0.02 |
| 50C-1441-54 | 14(41) XLP SIS UL3173 Tinned Copper Green with Yellow Stripe | 0.02 |
| 50C-1441-64 | 14(41) UL3173 SIS Tinned Copper 600 Volt Blue with Yellow Stripe | 0.02 |
| 50C-1441-96 | 14(41) XLP SIS UL3173 Tinned Copper 125C 600 Volt White with Blue Stripe | 0.02 |
| 50C-1626-0 | 16(26) XLP SIS UL3173 Tinned Copper 125C 600 Volt Black | 0.01 |
| 50C-1626-01 | 16(26) XLP SIS UL3173 Tinned Copper 600volt Brown | 0.01 |
| 50C-1626-02 | 16(26) XLP SIS UL3173 Tinned Copper 125C 600 Volt Red | 0.01 |
| 50C-1626-03 | 16(26) XLP SIS UL3173 Tinned Copper 125C 600 Volt Orange | 0.01 |
| 50C-1626-04 | 16(26) XLP SIS Ul3173 Tinned Copper 125C 600 Volt Yellow | 0.01 |
| 50C-1626-05 | 16(26) XLP SIS UL3173 Tinned Copper 125C 600 Volt Green | 0.01 |
| 50C-1626-06 | 16(26) XLP SIS UL3173 Tinned Copper 125C 600 Volt Blue | 0.01 |
| 50C-1626-07 | 16(26) XLP SIS UL3173 Tinned Copper 125C 600Volt Purple | 0.01 |
| 50C-1626-08 | 16(26) XLP SIS UL3173 Tinned Copper 125C 600 Volt Gray | 0.01 |
| 50C-1626-09 | 16(26) XLP SIS UL3173 Tinned Copper 125C 600 Volt White | 0.01 |
| 50C-1626-54 | 16(26) XLP SIS UL3173 Tinned Copper 125C 600 Volt Green with Yellow Stripe | 0.01 |
| 50C-1626-64 | 16(26) XLP SIS UL3173 Tinned Copper 125C 600 Volt Blue with Yellow Stripe | 0.01 |
| 50C-1626-96 | 16(26) XLP SIS UL3173 Tinned Copper 125C 600 Volt White with Blue Stripe | 0.01 |
| 50C-1816-0 | 18(16) XLP SIS Tinned Copper 125C 600 Volt Black | 0.01 |
| 50C-1816-01 | 18(16) XLP SIS Tinned Copper 125C 600 Volt Brown | 0.01 |
| 50C-1816-02 | 18(16) XLP SIS UL3173 Tinned Copper 125C 600 Volt Red | 0.01 |
| 50C-1816-02P | 18(16) UL3173 Tinned Copper Red | 0.01 |
| 50C-1816-03 | 18(16) XLP SIS Tinned Copper 125C 600 Volt Orange | 0.01 |
| 50C-1816-04 | 18(16) XLP SIS Tinned Copper 125C 600 Volt Yellow | 0.01 |
| 50C-1816-04P | 18(16) UL3173 Tinned Copper Yellow | 0.01 |
| 50C-1816-05 | 18(16) XLP SIS Tinned Copper 125C 600 Volt Green | 0.01 |
| 50C-1816-05P | 18(16) UL3173 Tinned Copper Green | 0.01 |
| 50C-1816-06 | 18(16) XLP SIS Tinned Copper 125C 600 Volt Blue | 0.01 |
| 50C-1816-06P | 18(16) UL3173 Tinned Copper Blue | 0.01 |
| 50C-1816-07 | 18(16) XLP SIS Tinned Copper 125C 600 Volt Purple | 0.01 |
| 50C-1816-08 | 18(16) XLP SIS Tinned Copper 125C 600 Volt Gray | 0.01 |
| 50C-1816-09 | 18(16) XLP SIS Tinned Copper 125C 600 Volt White | 0.01 |
| 50C-1816-09P | 18(16) UL3173 Tinned Copper White | 0.01 |
| 50C-1816-0P | 18(16) UL3173 Tinned Copper Black | 0.01 |
| 50C-1816-69 | 18(16) Ul3173 XLP SIS Tinned Copper 600 Volt Blue with White Stripe | 0.01 |
| 50C-1816-96 | 18(16) UL3173 SIS Tinned Copper White with Blue Stripe | 0.01 |
| 50C-2010-02 | 20(10) XLP SIS Tinned Copper 125C 600 Volt Red | 0.01 |
| 50C-2207-01 | 22(07) XLP SIS Tinned Copper 125C 600 Volt Brown | 0.01 |
| 50C-2207-03 | 22(07) XLP SIS Tinned Copper 125C 600 Volt Orange | 0.01 |
| 50C-2207-04 | 22(07) XLP SIS Tinned Copper 125C 600 Volt Yellow | 0.01 |
| 50C-2207-05 | 22(07) XLP SIS Tinned Copper 125C 600 Volt Green | 0.01 |
| 50CS-02133-08 | 2 (133) XLP SIS VW-1 Tinned Copper 90C 600 Volt Gray | |
| 50CS-10105-0 | 10(105) XLP SIS VW-1 Tinned Copper 125C 600 Volt Black | |
| 50CS-10105-05 | 10(105) XLP SIS Tinned Copper125C 600 Volt VW-1 Green | |
| 50CS-10105-08 | 10(105) XLP SIS VW-1 Tinned Copper 125C 600 Volt Gray | |
| 50CS-1265-02 | 12(65) XLP SIS VW-1 Tinned Copper 125C 600 Volt Red | |
| 50CS-1265-05 | 12(65) XLP SIS VW-1 Tinned Copper 125C 600 Volt Green | |
| 50CS-1265-06 | 12(65) XLP SIS VW-1 Tinned Copper 125C 600 Volt Blue | |
| 50CS-1265-09 | 12(65) XLP SIS VW-1 Tinned Copper 125C 600 Volt White | |
| 50CS-1265-62 | 12(65) UL3173 SIS VW-1 Tinned Copper Blue with Red Stripe | |
| 50CS-1265-69 | 12(65) UL3173 SIS VW-1 Tinned Copper Blue with White Stripe | |
| 50CS-1265-96 | 12(65) UL3173 SIS VW-1 Tinned Copper White with Blue Stripe | |
| 50CS-1441-0 | 14(41) UL44 SIS VW-1 Tinned Copper Black | 0.02 |
| 50CS-1441-05 | 14(41) XLP SIS VW-1 Tinned Copper 125C 600 Volt Green | |
| 50CS-1441-08 | 14(41) XLP SIS VW-1 Tinned Copper 125C 600 Volt Gray | 0.02 |
| 50CS-1626-08 | 16(26) XLP SIS UL3173 VW-1 Tinned Copper 125C 600 Volt Gray | |
| 50CS-1816-0 | 18(16) XLP SIS VW-1 Tinned Copper 125C 600 Volt Black | |
| 50CS-1816-02 | 18(16) XLP SIS VW-1 Tinned Copper 125C 600 Volt Red | |
| 50CS-1816-06 | 18(16) XLP SIS VW-1 Tinned Copper 125C 600 Volt Blue | |
| 50CS-1816-08 | 18(16) XLP SIS VW-1 Tinned Copper 125C 600 Volt Gray | |
| 50CS-1816-96 | 18(16) XLP SIS VW-1 Tinned Copper 125C 600 Volt White with Blue Stripe |
SIS Questions and Answers
What is SIS wire?
SIS is a 600V single-conductor wire with cross-linked polyethylene (XLPE) insulation, listed under UL 44. The name comes from its original designation: switchboard wire, insulated, stranded. It is the standard internal wiring for switchboards, panelboards and switchgear.
What is SIS wire rated for?
600V and 90°C in dry locations, with a VW-1 flame rating. The conductor is stranded copper, commonly tinned. Amps by size are on the SIS wire ampacity chart.
Why do switchboards use SIS instead of THHN?
SIS insulation is a thermoset: it chars in place and keeps its shape, where thermoplastic wire such as THHN softens and melts when it gets hot. Inside a crowded switchboard, where conductors are bundled and terminate on lugs that heat up, that is why UL 891 and switchgear standards call for SIS-type wire.
What is the difference between SIS and MTW?
SIS has thermoset XLPE insulation and belongs in switchboards and switchgear. MTW has thermoplastic PVC insulation and belongs in industrial machine panels (NFPA 79). See the SIS wire guide for the full comparison with THHN.
Should I order tinned or bare copper SIS?
Tinned copper resists corrosion and solders cleanly, which is why it is the common choice for switchboard work. Order by gauge, color and tinned or bare, on spools or in cut lengths.
Something else? Call (918) 622-1489 or send us the size and length you need.