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Product

Hook-up & equipment wiresUL 44 Type SIS · UL 3173600 V · 90 °C SIS / 125 °C AWMSubstation & Switchgear

UL AWM 3173 / SIS Switchboard WireDual-rated UL 44 Type SIS (90 °C) & UL AWM 3173 / CL1251 (125 °C) 600 V switchboard wire

Utility substation, MV/LV switchgear and Class F motor lead wire dual-certified to UL 44 Type SIS Switchboard Wire (90 °C, 600 V) and UL AWM Style 3173 / CSA CL1251 (125 °C, 600 V), featuring tinned copper conductors (22–4/0 AWG) and thermoset XLPE insulation.

Flame-retardant
Oil-resistant
Ozone, UV & moisture
Approved
Order designation
UL 3173 / SIS 14 AWG
Outer Ø min
3.2 mm
Outer Ø max
3.5 mm
Weight ≈
27 kg/km
Min. bend R
14 mm
Check against my drumAll sizes (10)
Request a quoteDatasheetWhatsApp
Engineering reply in 2 business hoursCut-to-length export drumsEN 10204 3.1 certificate per drum
Voltage rating
600 V RMS
UL 44 Type SIS & UL AWM 3173 / CL1251
Temp. rating
90 °C / 125 °C
90 °C (UL 44 SIS) · 125 °C (UL 3173)
Insulation wall
0.76 mm (30 mil)
30 mil (22–10 AWG) · 45–80 mil (8–4/0)
Flame rating
VW-1 / FT1 / FT2
UL 44 vertical flame & VW-1 / CSA FT1
Short-circuit
+250 °C
Thermoset XLPE resists CT/PT fault heat
Size range
22–4/0 AWG
0.33–107 mm² · Class B or flex CuSn

Typical values for this cable type, based on UL 44 Type SIS · UL 758 Style 3173 · CSA CL1251 — confirmed in the datasheet and quotation for your order.

Application fit

Is UL AWM 3173 / SIS right for your machine?

Specify dual-rated UL 3173 / Type SIS wherever ANSI/IEEE C37 switchgear standards, utility substation protection panels or Class B/F rotating machines demand a 600 V thermoset XLPE wire that will never deform or melt under CT secondary circuits, heater strips or lug hotspots.

Fixed installation

Suitable

ANSI C37 MV/LV switchgear cubicles, utility relay panels, CT/PT secondary wiring and Class B/F motor leads.

VFD inverter to AC motor screened feeder

With conditions

Thermoset XLPE insulation resists corona and thermal stress in drive cabinets; unscreened single-core.

Trailing & towing

Not suitable

Fixed switchboard, conduit and internal apparatus wire.

Use EN 50264-2-2

Energy chain / drag chain

Not suitable

For NFPA 79 PLC panels where thermoplastic PVC MTW is specified, see UL 1015 / MTW / TEW.

Use UL 1015 / MTW
Typical machinesANSI/IEEE C37 MV & LV metal-clad switchgearUtility substation protection & relay panelsCurrent & potential transformer (CT/PT) circuitsClass B / Class F motor & generator leadsSwitchboard busbar & breaker control harnesses

Construction

Layer by layer

Shown: UL 3173 / Type SIS 14 AWG (41/30 or 7-strand Class B) — tinned annealed copper conductor (2.08 mm²), 0.76 mm (30 mil) grey or black flame-retardant cross-linked polyethylene (XLPE) dielectric and VW-1 / FT1 surface legend.

123
Schematic, not to scale — generated from the layer data
#LayerMaterial & reference
1Tinned or bare annealed copper7-strand Class B (for utility switchboard terminal blocks) or flexible 19/41/65-strand tinned copper (for hinged relay doors and motor leads)ASTM B33 / B8 · UL 44 · UL 758
20.76 mm (30 mil) flame-retardant XLPEChemically or electron-beam cross-linked polyethylene meeting both UL 44 Type SIS and UL 758 Style 3173UL 44 Type SIS · UL 758 Style 3173
3Low-friction VW-1 switchboard finishSmooth thermoset outer surface engineered for neat 90-degree bundle dressing and high-density terminal-block wiring in utility panelsUL 44 · CSA C22.2 No. 38 / No. 210

UL 44 Type SIS / UL 3173 7-Strand Class B Tinned Copper (18–4/0 AWG)

Semi-rigid 7-strand tinned copper preferred by electric utilities for self-supporting relay-panel wiring

UL 3173 / Type SIS / CSA CL1251 Flexible Stranded Tinned Copper (22–4/0 AWG)

Flexible 19/26/41/65-strand tinned copper for hinged breaker doors, motor leads and transformer coils

Technical data

Ratings & operating limits

Typical values: Typical values for this cable type, based on UL 44 Type SIS · UL 758 Style 3173 · CSA CL1251. Values for your order are confirmed in the datasheet and quotation.

Electrical

Rated voltage
600 V RMS
Dielectric withstand voltage
2000 V AC for 1 min · 6000 V AC spark test
Max. DC conductor resistance (20 °C)
18 AWG: ≤ 21.0 Ω/km · 16 AWG: ≤ 13.2 Ω/km · 14 AWG: ≤ 8.28 Ω/km · 12 AWG: ≤ 5.21 Ω/km · 10 AWG: ≤ 3.28 Ω/km

Thermal

Continuous temperature rating
+90 °C dry (UL 44 Type SIS NEC rating) · +125 °C continuous (UL AWM Style 3173 & CSA CL1251)
Overload & short-circuit rating
+130 °C emergency overload · +250 °C short-circuit rating

Mechanical

Nominal insulation wall
22–10 AWG: 0.76 mm (30 mil) · 8 AWG: 1.14 mm (45 mil) · 6–2 AWG: 1.52 mm (60 mil)
Min. bending radius
4 × overall diameter (fixed switchboard routing)

Resistance

Flame retardance
UL 44 Horizontal / Vertical flame test, UL 1581 VW-1 & CSA FT1 / FT2 (IEEE 383 / VW-1 utility grade)
Crush, oil & varnish resistance
Thermoset XLPE resists terminal screw creep, oil mist, ozone and Class F varnish baking

Reference standards

Primary switchboard standard
UL 44 Type SIS (Switchboard Wire, 600 V, 90 °C) & NEC Article 310 / ANSI C37.20
Appliance & motor lead standards
UL 758 AWM Style 3173 (600 V, 125 °C) & CSA C22.2 No. 210 Type CL1251 (or CSA SIS)
RoHS & REACH
2011/65/EU (RoHS 2) & EC 1907/2006 compliant

Identification

Utility switchboard colours
Grey (standard utility relay colour), Black, White, Red, Blue, Yellow, Green, Orange, Brown & Violet
Surface marking
E-File [AWG] SIS 600V 90C — AWM STYLE 3173 125C 600V XLPE VW-1 CSA CL1251 125C TEBAOFLEX
Customs tariff (HS)
8544.49 (insulated conductors ≤ 1000 V)

Sizes

10 standard UL AWM 3173 / SIS configurations

Typical UL 44 Type SIS · UL 758 Style 3173 · CSA CL1251 outer diameter limits, copper content and cable weight.

Dimensions & weights
Order designationCores × mm² / AWGAWG ≈Outer Ø min
mm		Outer Ø max
mm		Copper
kg/km		Weight ≈
kg/km		Min. bend R
mm		Enquiry
600 V Switchboard & Relay Panel Wire (UL 44 SIS / AWM 3173, 20–10 AWG)
UL 3173 20 AWG (10/30)20 AWG (0.52 mm²)202.32.551010
UL 3173 / SIS 18 AWG18 AWG (0.82 mm²)182.62.871311
UL 3173 / SIS 16 AWG16 AWG (1.31 mm²)162.93.1121912
UL 3173 / SIS 14 AWG14 AWG (2.08 mm²)143.23.5202714
UL 3173 / SIS 12 AWG12 AWG (3.31 mm²)123.74.0314016
UL 3173 / SIS 10 AWG10 AWG (5.26 mm²)104.34.7506119
600 V Heavy Switchgear & CT/Motor Leads (UL 44 SIS / AWM 3173, 8–2 AWG)
UL 3173 / SIS 8 AWG8 AWG (8.37 mm²)85.96.48010426
UL 3173 / SIS 6 AWG6 AWG (13.3 mm²)67.58.112716532
UL 3173 / SIS 4 AWG4 AWG (21.2 mm²)48.79.520325238
UL 3173 / SIS 2 AWG2 AWG (33.6 mm²)210.211.132238544
  • Typical values for this cable type; dimensions and weights for your order are confirmed in the quotation.
  • Dimensions and weights are typical values per UL 44 Type SIS · UL 758 Style 3173 · CSA CL1251. Minimum fixed bending radius shown is 4 × OD.

Reel check

Will it fit your machine?

A first screen using datasheet values. Engineering confirms drum geometry, acceleration and tension with your quotation.

Check results

Drum core 300 mm ≥ 28 mmBending radius OK (4 × OD 3.5 mm)
Minimum bending radius
14 mm
Min. drum core diameter
≈ 28 mm
Cable weight on drum
1.4 kg
Copper content
1.0 kg
Indicative only: based on the datasheet outer diameter and 4 × OD bending radius. Current derating for wound layers per DIN VDE 0298-4 is assessed separately.

Quality & approvals

Testing & inspection

Routine tests on every production length, sample and type tests per batch — documented on an EN 10204 3.1 inspection certificate.

  1. ConductorClass 5 stranding
  2. Spark test100 % in-line
  3. Lay-upCores, earth, fillers
  4. SheathingInner, braid / screen, outer
  5. Electrical testsAC voltage, resistance
  6. DimensionsOD, wall thickness
  7. Inspection documents & dispatchDrum & dispatch
Testing & inspectionTest value / referenceFrequency
Routine tests
AC dielectric voltage test2.0 kV AC (50/60 Hz)Every manufactured length
Conductor DC resistanceIEC 60228 / ASTM (tinned copper)Every manufactured length
Sample tests
Flame propagation testIEC 60332-1-2 / UL VW-1 / ISO 6722-1Per production batch
Insulation & sheath material physical propertiesUL 44 Type SIS · UL 758 Style 3173 · CSA CL1251Type approval

Inspection certificate

Issued with every drum, listing the routine test results for that length.

Product approvals

UL 44 Type SIS · UL 758 Style 3173 · CSA CL1251CE · RoHS 2 (2011/65/EU) · REACH

Company certificates

ISO 9001ISO 14001ISO 45001VDE marks approvalUL / cULCE · LVD / EMC

Marking & supply

Ordering & delivery

Sheath marking

[AWG] SIS 600V 90C — AWM 3173 125C 600V XLPE VW-1 CSA CL1251 TEBAOFLEX
Delivery form
Export wooden drums, reels or coils, cut-to-length on request
Packaging
Heat-treated ISPM-15 timber drums or spools with sealed ends
Conductor / colour options
Custom core counts, stripe combinations or cut harnesses on request

Technical documents

Downloads

PDFUL AWM 3173 / SIS Switchboard Wire – technical datasheet10 sizes · construction, technical data, approvalsXLSXUL AWM 3173 / SIS spec data (Excel)All 10 sizes with dimensions and data, for your BOM or quotation
Revision
2026-10-20
Updated
2026-10-20

FAQ

Questions engineers ask first

Not covered here? Send your drawing — an engineer replies within 2 business hours.

What is UL 44 Type SIS switchboard wire and why do electric utilities mandate it?
Type SIS (Synthetic Insulated Switchboard wire) under UL 44 and NEC Table 310.104(A) is a 600 V thermoset cross-linked polyethylene (XLPE) conductor engineered specifically for utility substation relay panels and ANSI/IEEE C37 switchgear. Unlike PVC (MTW/THHN), thermoset SIS cannot melt or flow under high-current CT secondary faults or loose terminal hotspots.
Why is grey the most common colour for Type SIS switchboard wire?
Electric utilities and ANSI C37 switchgear builders traditionally specify neutral grey (or black) Type SIS wire across relay and breaker cubicles so printed wire-marker sleeves at every terminal block stand out with maximum visual contrast.
What is the difference between 7-strand Class B and flexible stranded SIS / UL 3173?
7-strand Class B tinned copper is semi-rigid, allowing utility panel wirers to form crisp, self-supporting 90-degree wire bundles without plastic trunking. Flexible 19/26/41/65-strand tinned copper is used across hinged relay cabinet doors and for Class B/F motor leads.
Why does the same wire carry both a 90 °C (SIS) and a 125 °C (UL 3173 / CL1251) rating?
Under NEC Article 310 and UL 44, Type SIS building/switchboard wire is assigned a conservative 90 °C ampacity column to match 75 °C/90 °C switchgear terminations, while the identical XLPE compound passes UL 758 Style 3173 and CSA CL1251 long-term thermal aging at +125 °C for internal apparatus and motor leads.

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UL AWM 3173 / SIS Switchboard Wire

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