UL 5359 Multi-Conductor Mica Cable for Protected Internal Wiring
UL AWM Style 5359 is a single or multi-conductor with other-than-extruded insulation, rated 200 or 450°C and 600 Vac with a Horizontal flame classification. Each conductor is insulated with mica tape and a glass braid treated with silicone varnish or PTFE finish. The Style permits two or more of these insulated conductors to be cabled together into one assembly with a maximum O.D. of 1.500 inches. Its Use is internal wiring where not subjected to repeated flexing and protected from mechanical abuse.
This page covers that multi-conductor construction: what the Style permits for the assembly, which elements are optional, what each conductor must meet, and what an RFQ must state for the assembly to be confirmed. The single-conductor form of the Style is covered on the separate UL 5359 single-conductor page. For the broader Style overview, see the UL 5359 Mica Wire category.
Verified UL 5359 Technical Specifications
| Parameter | UL AWM Style 5359 record |
|---|---|
| Style | 5359 |
| Description | Single or multi-conductor with other-than extruded Insulation |
| Rating | 200 or 450°C, 600 Vac |
| Flame | Horizontal flame |
| Overall conductor range | 30 AWG – 4/0 AWG |
| Conductor form | Solid or stranded in sizes 26 – 8 AWG; larger sizes stranded only |
| Insulation | Mica tape with Glass Braid treated with Silicone varnish or PTFE finish |
| Thickness, 30–12 AWG | Total mica tape layers 16 mils min avg; treated glass braid 7 mils min avg |
| Thickness, 11–4 AWG | Total mica tape layers 20 mils min avg; treated glass braid 15 mils min avg |
| Thickness, 3–4/0 AWG | Total mica tape layers 25 mils min avg; treated glass braid 20 mils min avg |
| Assembly (optional) | Two or more insulated conductors may be cabled together, max O.D. 1.500 inches (38.1 mm by unit conversion); mica glass binder and/or fiberglass fillers may be employed |
| Covering (optional) | Treated glass braid |
| Shield (optional) | 36–30 AWG Type “A” Nickel or 27 percent minimum nickel coated copper |
| Marking | General |
| Use | Internal wiring where not subjected to repeated flexing and protected from mechanical abuse, and where the acceptability, including current-carrying capacity, has been determined by Underwriters Laboratories Inc. |
Four points in this table need clarification. First, the conductor-form rule covers 26–8 AWG and sizes above 8 AWG; the record does not state the permitted form for 30–27 AWG, so it is confirmed for the qualified construction. Second, all thickness values are minimum averages for the individual conductors; the record states no minimum-at-any-point value. Third, the binder, fillers, covering and shield are each optional and independent. Fourth, the shield materials are for the shield only; the record does not state the primary conductor material or plating.
Two or More Insulated Conductors, Maximum 1.500-Inch Assembly OD
The assembly entry reads: “Optional, two or more insulated conductors described above, may be cabled together with a max O.D. of 1.500 inches.” Three points follow directly.
- Each conductor is a qualified Style 5359 conductor. “Insulated conductors described above” means conductors that meet the Style’s own conductor, mica tape and glass-braid requirements.
- “Two or more” is a minimum, not a list. The Style defines no core counts and no maximum count. No standard configurations are offered, and the number of conductors that fit within the limit is not estimated here.
- 1.500 inches is a maximum. It is the upper limit for the assembly O.D., not a standard, typical or target diameter. The actual finished assembly diameter depends on the conductor size and construction, the number of conductors and the options used, and is confirmed for the ordered configuration.
The record does not state whether conductors of different sizes, or conductors serving different circuit functions, may be combined in one assembly. If a mixed construction is requested, it is confirmed against the qualified construction and the equipment requirements before quotation; it is not assumed to be permitted.
Mica Glass Binder and Fiberglass Fillers
The Style states: “A mica glass binder and/or fiberglass fillers may be employed.” Either may be used alone, both may be used together, or neither may be used. The record names these materials without assigning them a function; it does not state that they hold conductors in position, accommodate different conductor sizes, improve roundness or affect mechanical, thermal or dimensional performance, and none of these effects is claimed here. Whether binder, fillers or both are required is stated in the RFQ.
Optional Overall Treated Glass Braid
A multi-conductor UL 5359 construction can involve two separate glass braids, and they should not be confused:
- Each insulated conductor’s braid: part of the insulation of every conductor (mica tape with glass braid treated with silicone varnish or PTFE finish), required, with a minimum-average thickness set by size group.
- The optional covering: the Covering entry reads “Optional, treated glass braid.” For a multi-conductor order, whether this covering is applied over the completed assembly is stated in the RFQ and confirmed for the ordered construction.
The record gives no thickness for the optional covering and assigns it no abrasion, temperature or mechanical effect. It is not described as essential at any conductor count, and it does not make the assembly suitable for exposed routing or field wiring.
Individual Conductor Mica Tape and Glass Braid Construction
| Conductor size group | Total mica tape layers, min average | Treated glass braid, min average |
|---|---|---|
| 30 – 12 AWG | 16 mils | 7 mils |
| 11 – 4 AWG | 20 mils | 15 mils |
| 3 – 4/0 AWG | 25 mils | 20 mils |
Three points in this table need clarification. First, “total mica tape layers” is the combined thickness of all mica tape layers on a conductor. Second, all values are minimum averages; none is nominal, typical, exact or a point minimum, and neither the insulated-conductor diameter nor the assembly diameter is calculated from them. Third, the record attributes no flexibility, mechanical or dielectric performance to these thicknesses.
The insulation is mica tape. It is not described as composite mica glass, MI cable, mineral insulation or ceramic insulation. The braid treatment is silicone varnish or PTFE finish; both are braid finishes, not primary insulation. The Style does not tie either treatment to a temperature rating or rank them. The record does not define conductor material, plating, strand count, strand diameter, conductor class, lay length or resistance.
200°C or 450°C / 600 Vac / Horizontal Flame
The rating field reads “200 or 450 deg C, 600 Vac, Horizontal flame.” The Style carries two alternative temperature ratings. A given construction is qualified at one of them, so not every UL 5359 construction is a 450°C construction; the rating for an order is confirmed for the qualified ordered construction and its marking. Neither rating is described in the record as continuous or long-term.
600 Vac is the voltage rating; no DC value is stated. The rating does not make the assembly a power-distribution cable, and it does not establish suitability for any particular supply system. Horizontal flame is the flame classification; VW-1, FT1, FT2 and vertical flame are not Style-wide properties.
Optional Shield
The Shield entry reads: “Optional, 36-30 AWG Type “A” Nickel or 27 percent minimum nickel coated copper.” Only these two shield materials are listed for Style 5359. They are shield materials, not the material of the primary conductors. The record establishes no shielding effectiveness, EMI attenuation, abrasion, mechanical or heat-shielding performance for the shield, and none is claimed here. Whether a shield is required, and where it is applied in the construction, is stated in the RFQ.
Protected Internal Wiring — No Repeated Flexing
The Use reads: “Internal wiring where not subjected to repeated flexing and protected from mechanical abuse, and where the acceptability, including current-carrying capacity, has been determined by Underwriters Laboratories Inc.” Each condition applies to the multi-conductor assembly:
- Internal wiring: the Use does not designate specific equipment, and UL 5359 is not described here as furnace, kiln, oven, heater or instrumentation cable. Equipment context is confirmed with the buyer’s actual requirements. Because the rating is 200 or 450°C, the assembly can be described as a high-temperature mica cable for protected internal wiring, without widening the Use.
- Not subjected to repeated flexing: the assembly is not a flexible, high-flex, continuous-flex, drag-chain or moving-equipment cable, and no bend radius or flex life is given.
- Protected from mechanical abuse: exposed, field, building, tray, outdoor, direct-burial and moving runs fall outside the Use. The optional shield and optional covering do not remove this condition.
- Acceptability, including current-carrying capacity, determined by UL: no ampacity is published or derived from AWG, and no conductor size is identified as suitable for a particular load.
What Style 5359 Does and Does Not Define for Multi-Conductor Assemblies
The Style record defines the rating; the conductor range and forms (except the form for 30–27 AWG); the mica tape and treated-glass-braid minimum averages by group; the braid treatments; the optional assembly of two or more insulated conductors within 1.500 inches; the optional binder, fillers, covering and shield; the marking field (General); and the Use.
The Style record does not define:
- core counts, a maximum count or standard configurations
- mixed-size or mixed-function assemblies
- finished conductor or assembly diameter
- conductor identification or colour coding
- conductor material, plating, strand construction or resistance
- current rating
- bend radius, termination methods or breakout lengths
Common Procurement Errors
- Treating 1.500 inches as the standard assembly diameter.
- Requesting a core count without confirming it fits within the maximum O.D.
- Assuming mixed conductor sizes or functions are automatically permitted.
- Assuming binder, fillers, covering or shield are included by default.
- Confusing each conductor’s braid with the optional covering.
- Assuming every UL 5359 construction is rated 450°C.
- Assuming a conductor form for 30–27 AWG, or a solid conductor above 8 AWG.
- Specifying the assembly for repeated flexing or unprotected routing.
How to Specify a UL 5359 Multi-Conductor Assembly in an RFQ
The Style fixes the rating options, the conductor and insulation requirements, the assembly provision and the Use. The following should be stated by the buyer and confirmed for the ordered qualified construction; a requested construction is not assumed to be within the qualified scope until confirmed:
- required temperature rating: 200°C or 450°C
- individual conductor AWG
- required conductor material and plating
- conductor form, where applicable
- detailed stranding, if controlled
- number of conductors
- whether all conductors are the same size, or the configuration requested
- finished assembly OD and tolerance requirement
- binder requirement
- fiberglass filler requirement
- optional overall treated glass braid requirement
- optional shield requirement
- conductor identification and marking requirement
- equipment type
- internal routing condition
- confirmation that the cable is not subjected to repeated flexing
- mechanical-protection arrangement
- current requirement
- quantity
- packaging
- documentation requirements
UL Marking and Documentation
Style 5359 wire is supplied as UL-recognized component wire where supplied under qualified manufacturing scope. The marking field of the Style record reads “General”; it does not prescribe a fixed legend, and identical marking is not assumed for every assembly configuration or temperature rating. UL marking is applied according to the confirmed ordered construction and should be confirmed at the order stage.
Applicable RoHS / REACH documentation can be confirmed according to the ordered construction. CE, UKCA, CSA, FT1, VW-1, CPR, VDE, DIN, EN and IEC are not declared for this product.
Commercial, origin, compliance and transport documents are identified during quotation and confirmed according to the order.
