A robotic workcell wiring duct must carry UL 94 V-0 flammability rating, lead-free PVC or self-extinguishing ABS construction, CE plus RoHS plus REACH evidence, and a recognized continuous use temperature of at least +50°C to pass integrator audit.
Common reference ducts in this class include HellermannTyton TSR2-8A (PVC, white) and TSR3-50 (ABS, beige) raceway-system accessories, both marked for power or data installation and designed to clip onto matching faceplate duct profiles [S2][S5]. For a deeper primer on the duct family itself, see the wiring duct reference page.
Scope: What This Checklist Covers and Excludes
The checklist governs rigid PVC or ABS slotted wiring ducts used inside the electrical enclosure of a robotic workcell, not flexible cable carriers, corrugated looms, or floor-level拖链 that move with the robot [S1]. It covers base duct, cover cap, mounting holes, slot pattern, and end-of-row accessories such as the TSR faceplate family.
Out of scope are the power conductors themselves, the servo drives, and any cable gland entries that penetrate the panel wall, which follow separate component rules (e.g. UL 514B for conduit fittings, IEC 60079 series for hazardous areas). If the workcell sits in an ATEX or IECEx zone, the duct must additionally be rated static-dissipative; standard off-the-shelf PVC ducts sold on generic B2B portals do not meet that bar [S4].
Mandatory Markings and Document Set
A compliant workcell duct ships with a UL file number such as E485189 (RCCN terminal family, also covering duct accessories), a CE Declaration of Conformity referencing the Low Voltage Directive 2014/35/EU and RoHS 2.0, and a REACH statement covering the 73 SVHC item list per the 2020 update pattern [S3][S4].
The supplier's test pack must include a flammability report at UL 94 V-0, a RoHS test for the 6 restricted substances plus 4 phthalates plus 1D, a continuous-use temperature curve, and an impact or deflection test at the published low temperature limit. RCCN's published pack (PVC, PP, PE, PA6, nylon PA66, EPDM, tin plating, copper, cold-rolled steel, 304 stainless, galvanised steel, 316 stainless) is a usable template for which raw-material certificates the audit will look for [S3]. Generic CE-marked ducts on B2B portals (e.g. Okorder-listed "CE WIRING DUCT") typically claim UL-94 V-0 PVC and the same four-piece document set, but the test report numbers and lab must be requested before order release [S4].
Material, Flammability, and Temperature Criteria
Two material families dominate the workcell duct market: rigid lead-free PVC (UL 94 V-0, recognised continuous use temperature +50°C / +122°F, hardness specified for impact retention) and self-extinguishing ABS for the accessory / faceplate system [S4][S5]. The 50°C floor is not generous: a sealed workcell cabinet sitting next to a 6-axis robot controller regularly runs 10–15°C above ambient, so any duct rated only to +40°C will drift past its limit on a summer day.
Compare the three realistic options on the four criteria that decide most bids: hard lead-free PVC (cost low, V-0 yes, +50°C ceiling, no ESD option), self-extinguishing ABS (cost mid, V-0 yes, +70°C ceiling, no ESD option), and static-dissipative coated PVC (cost high, V-0 yes, +50°C ceiling, ESD-safe, required for ATEX workcells). For non-hazardous workcells, hard lead-free PVC remains the default because the +50°C ceiling and V-0 rating are sufficient and the price spread versus ABS is typically 20–30% [S2][S4].
Mechanical and Dimensional Checks
Each duct segment must show a smooth cover-cap match, no peeling along the score line, and standard mounting holes on a 25 mm or 50 mm pitch, with slot holes on both sides for finger access during cable lay-in [S4]. The published construction is "bottom duct plus cover cap, slot holes in both side," which is the same geometry that most panel shops expect for off-the-shelf cutting tools.
For a workcell cabinet the practical cut lengths are 1 m or 2 m, with cover supplied in 48.80 m reels for the TSR2-8A family [S5]. Cross-section sizing follows the 40% fill rule called out in most panel-builder standards: pick a duct whose internal area is at least 2.5× the summed CSA of the planned cable bundle, otherwise the cover will not seat cleanly and the V-0 rating becomes moot because the cap is propped open.
Chemical and Environmental Compliance Tests
The RoHS pack must show 6 restricted substances plus 4 phthalates plus 1D, and the REACH pack must confirm that none of the 73 SVHC items in the 2020 update appear above the 0.1% w/w threshold [S3]. Where the cabinet is exposed to cutting fluid or weld spatter, request an additional oil-resistance and red-phosphorus test for the nylon PA66 cover clips, again following the RCCN 2018-07 test pattern [S3].
For an integrators' bill of materials, the matching accessory family matters as much as the base duct: the TSR faceplate series (TSR2-8A, TSR3-50, and similar) clips onto the duct slot without tools and is supplied in 10-piece accessory packs or 48.80 m cover reels depending on the part code [S2][S5]. If the supplier cannot supply the matching faceplate part number alongside the duct, the install will fall back to adhesive, which then invalidates the V-0 claim on the adhesive.
Verification: How to Audit a Supplier's Certificate
Open the supplier's UL file directly at https://www.ul.com and search the file number; the file must list "Wiring Duct" or "Raceway" in the product category, not just "Terminal Block," otherwise the scope does not cover the part you are buying [S3]. Verify the CE DoC lists the correct directive numbers (2014/35/EU, 2011/65/EU + 2015/863 for RoHS 2.0 + phthalates) and that the DoC date post-dates the last component change.
For the RoHS and REACH reports, confirm the issuing lab is ISO 17025 accredited, the report number matches the PDF on the supplier's media centre, and the test items explicitly include the four phthalates (DEHP, BBP, DBP, DIBP) added by the 2015/863 amendment [S3]. Where a HellermannTyton or equivalent branded duct is specified, the OEM's own media pack (e.g. TSR2-8A and TSR3-50 product pages) is the authoritative reference for both the part number format and the matching accessory [S2][S5].
Limitations and Common Failure Modes
Generic CE-marked ducts on trading portals (Okorder, Made-in-China listings) often state "UL 94 V-0" in the spec table but the actual report covers a different grade or a different colour compound, so always request a sample and a copy of the report under the bidder's name before issuing a PO [S4]. A second recurring failure is mixing duct brands within one cabinet: the cover-cap geometry from supplier A does not always clip cleanly onto supplier B's base duct, so the audit loses the V-0 seal along the joint.
A third pitfall is the enclosure thermal map: the workcell cabinet's hot spot near the servo drive often reaches +55°C to +60°C, which pushes a +50°C-rated PVC duct past its recognised continuous use temperature even though the panel-average is +35°C [S4]. For such cabinets, specify the ABS accessory family or uprate to a +70°C duct, and document the thermal map in the design review.
Decision Matrix: When Each Duct Family Is the Right Pick
Pick hard lead-free PVC when the workcell is non-ATEX, ambient inside the cabinet stays below +45°C, and cost is the driver; this covers the majority of palletising and pick-and-place cells [S4]. Pick self-extinguishing ABS for the accessory and faceplate components on the same cabinet, since ABS reaches +70°C and tolerates the cover-clip impact better than PVC [S2][S5]. Pick static-dissipative coated PVC only when the cell sits in an ATEX zone 2 or IECEx zone 2, and only with a supplier who can show the surface-resistance test at <1×10⁹ Ω, which is not part of the standard CE/RoHS pack and must be requested separately [S3].
Track these signals on the next PO cycle: the supplier's media centre update log (HellermannTyton publishes TSR family updates against the same part numbers), the UL file status for E485189 and any workcell-specific duct files, and any 2026 revision to the REACH SVHC candidate list that would push an existing part out of compliance. For the broader workcell hardware spec, the aerospace manufacturing equipment guide covers the adjacent selection logic for high-mix robotic cells.
For the relevant spec sheets and selection criteria, see spiral duct, and pressure transmitter.