The most common cable cleat sizing mistake is simple: the RFQ gives a cable type or voltage level, but not the actual outside diameter and trefoil bundle size. For wind turbine cable routes, those dimensions control the cleat body, liner compression, bolt reach and installation clearance.
Wind-energy clamp hub → Matched product page → Related procurement guide: SS316 Trefoil Cable Cleat for Offshore Wind Projects / Related procurement guide: SS316 vs Aluminum Trefoil Cable Cleats: Which One to Specify? / Related procurement guide: How to Specify Trefoil Cable Cleats for Wind Turbine Towers / Related procurement guide: Wind Turbine Cable Cleat RFQ Template: What Buyers Should Include / Related procurement guide: Cable Cleat Spacing in Wind Turbine Towers: Practical Design Notes / Related procurement guide: Wind Turbine Cable Cleat Inspection Checklist: What to Check During Maintenance / Related procurement guide: How to Specify Cable Cleats for Wind Turbine Tower Cables / Related procurement guide: How to Read an IEC 61914 Cable Cleat Test Report for Wind Projects
For a trefoil cable cleat RFQ, send the actual cable outside diameter, tolerance, three-core formation, measured or calculated trefoil bundle envelope, cable jacket material, support spacing, route location and whether the cleat must allow future cable replacement without changing the bracket.
- Best for
- Buyers, electrical engineers and site teams preparing RFQs for wind turbine tower, nacelle, transition-piece or offshore cable cleat routes.
- Not suitable for
- Selecting a cable cleat only from cable voltage or conductor cross-section without the finished cable OD.
- Selection steps
- 1 — Read the cable datasheet OD -> 2 — confirm OD tolerance -> 3 — calculate trefoil bundle envelope -> 4 — match liner compression -> 5 — send route and spacing data
- RFQ information
- Cable datasheet, finished OD, OD tolerance, trefoil layout, jacket material, bundle envelope, spacing, mounting rail or plate, quantity
§ 01 Cable voltage is not enough
A 66 kV cable from one manufacturer may not have the same finished diameter as another 66 kV cable. Conductor size, insulation system, screen, armour and outer jacket all change the final OD. The cleat should therefore be sized from the cable datasheet, not from voltage level alone.
§ 02 Use finished outside diameter, not conductor size
The supplier needs the finished cable outside diameter including jacket, armour and any sheath. If the project is still in design, send the nominal OD plus tolerance range. A few millimetres can change liner fit, especially on rigid stainless or aluminum trefoil cleats.
§ 03 Define the trefoil bundle envelope
In trefoil formation, three single-core cables touch or sit very close together. The cleat body is selected around the outside envelope of the three cables, not around a single cable. If the route uses spacers, separators or non-contact trefoil, include a sketch or photo.
§ 04 Check liner compression and cable jacket protection
The liner must hold the cable without cutting into the jacket or allowing slip. Too small a cleat over-compresses the cable; too large a cleat may not restrain the bundle during fault conditions. Jacket material and allowed compression should be part of the RFQ discussion.
§ 05 Connect OD data with spacing and short-circuit duty
Cable OD is only one part of the cleat choice. The same bundle size can require a different body or material when support spacing, short-circuit current or mounting stiffness changes. Keep this article linked with the RFQ template and IEC 61914 test report guide.
§ 06 What to send when drawings are incomplete
If final cable drawings are not released, send the closest supplier datasheet, target cable family, OD range, planned route and installation schedule. Ask the cleat supplier to state what dimensions must be frozen before production so the project avoids rework.
| RFQ field | Why it matters |
|---|---|
| Cable OD / bundle size | Controls the cleat body size and liner fit. |
| Short-circuit current | Defines IEC 61914 restraint duty. |
| Support spacing | Changes force per cleat and installation quantity. |
| Environment | Drives SS316, aluminum, fastener and liner choices. |
| Documents | Prevents rework during project approval and incoming inspection. |
Evidence and decision boundary
- Direct evidence
- IEC 61914 makes cable configuration and dimensions part of the declared/tested arrangement. Trefoil envelope cannot be selected from conductor size alone because cable construction and tolerances vary.
- Engineering inference
- Use manufacturer cable OD and the tested cleat's admissible cable range. Check three-cable geometry, liner compression, installation tolerance and thermal movement.
- Typical or indicative value
- Calculated trefoil envelopes and nominal-OD examples are estimating aids, not substitute dimensions for a purchase order or test report.
Primary sources checked
- IEC 61914:2021 - cable-cleat requirements and tests
- IEC 60865-1:2011 - short-circuit mechanical and thermal effects
- IEC 60909-0:2016 - three-phase AC short-circuit-current calculation
- Parker Catalogue 4100/UK - manufacturer clamp data
Related commercial route: Compare wind-turbine clamp systems and RFQ inputs.