Ellis Patents Flexi Strap | Cable Straps LV MV HV

Ellis Patents Flexi Strap | Cable Straps LV MV HV

Flexi Straps

flexi Straps

Trefoil Cable Straps for LV MV HV Cable Support 

  • Manufactured by Ellis Patents 
  • Type: Flexi Straps 
  • Maximum Short Circuit Test Level (Electromechanical Force) 134kA at 300mm Cable Cleat Intervals
  • Maximum Short Circuit Test Level (Electromechanical Force) 114kA at 600mm Cable Cleat Intervals
  • Use With Cable Cleat Type – Ellis Patents VULCAN+ and Emperor
  • Material – Stainless Steel / Heavy Duty 
  • Minimum Size Cable Straps  (Standard/Heavy Duty)- 24mm
  • Maximum Size Cable Straps (Standard/Heavy Duty) – 145mm

Flexi Straps are used at intermediate points between cable cleats to reduce the overall quantity of fixed cleats to ensure correct short circuit protection of power cables.

Cable Straps

Thorne & Derrick International, based in the UK, stock and distribute the complete range of cable cleats and hangers manufactured by Ellis Patents including Flexi Straps for short circuit retention and cable protection for the following LV (Low Voltage), MV (Medium Voltage) and HV (High Voltage) cable systems in single way and trefoil installation.

Ellis Patents Flexi Straps are heavy duty stainless steel strapped around the LV MV HV cable to secure, support and manage trefoil arrangement of power cables –  the Flexi Strap is then tightened and locked in place by using a patented buckle and spindle design. Standard duty straps are wrapped twice around the cables and Heavy Duty straps are wrapped three times.

For usage the strap has a special drive socket to then turn the spindle which is supplied with every 50 Flexi Straps that are ordered, the socket can be attached to a standard 1/4″ or 6mm ratchet handle.

International Standard: IEC61914:2015

Ellis Patents FlexiStrap which are certified and tested to international specifications are used to clamp and retain LV MV HV cables, including 11kV and 33kV networks depending on short-circuit calculations according to IEC61914 calculations.

Ellis Patents fLEXI sTRAP

This strap is available in a range of sizes with range taking ability to suit cables in trefoil formation or bundles of cables, with trefoil bundle diameters in 24-145mm range.

It is manufactured from corrosion resistant grade 316L stainless steel and supported with a low smoke and fume zero halogen LSOH material.

Installing Flexi Straps

Installation instructions for Flexi Strap with Trefoil Cleats manufactured by Ellis Patents:

Flexi Strap Instructions 1 Flexi Strap Installation 2 Flexi Strap Installation 3 Flexi Strap Installation 4
1. If supplied, remove the liner from the centre of the coiled FlexiStrap. Remove the blue securing tape and straighten the FlexiStrap. 2. Where appropriate, place the liner in the correct position along the cables. Wrap the liner around the cables with the side ridges on the outside of the assembly. Ensure that the tongue goes on the inside. 3. Attach the special tool onto a 1/4″ or 6mm ratchet handle. 4. Position the FlexiStrap over the Liner (where appropriate) and wrap around the cables, ensuring that the strap end passes under the square spindle each time. For Standard Duty the strap is wrapped twice around the cables, for Heavy Duty, the strap is passed around the cables three times.
Flexi Strap Installation 5 Flexi Strap Installation 6 Flexi Strap Installation 7 Flexi Strap Installation 8
5.Pass the two tangs of the end of the strap through the 2 holes in the square spindle and bend over the spindle tightly. 6. Using the 1/42 ratchet begin to turn the square end of the spindle clockwise, ensuring that the strap end remains in the spindle. 7.When the strap is tight around the cables, the square ratchet tool must be parallel to the top of the frame. This will ensure that the square spindle is “in line” with the square holes in the frame. 8. Using a 10mm spanner tighten the Nyloc nut at the other end of the spindle, thus drawing the spindle through the frame assembly.
Flexi Strap Installation 9
9. When correctly installed the square spindle should be in full location with the square hole in the frame.
Flexi Strap

Flexi Strap

The following Video demonstrates the installation procedure for the use of Flexi Straps manufactured by Ellis Patents and distributed in the UK by Thorne & Derrick.

Ellis Patents Flexi Strap Testing Information

Should you require test samples or further specification details about Flexi Straps please contact us:

Properties IEC 61914:2015 Classification Clause Units/Classification Test Data (Standard Duty) Test Data (Heavy Duty)
Cleat Type  6.1.3 Composite N/A N/A
Temp for permanent application 6.2 °C  -40 -60 -40 -60
Corrosion Resistance High 316L Stainless Steel has ≥16% Chromium 316L Stainless Steel has ≥16% Chromium
Impact Rating 6.3.5 Very Heavy PASS PASS
Flame Propagation Test 10.0, 10.1 Application Time ≥30s PASS PASS
Resistance to Electromechanical Force (Short Circuit Testing) 6.4, 6.4.4, 9.5 Cleats at 300mm intervals (Withstanding one short circuit) 134kA (Report No.PDL-18.122.3) Cable OD=Ø36mm
Resistance to Electromechanical Force (Short Circuit Testing) 6.4, 6.4.4, 9.5 Cleats at 600mm Intervals (Withstanding more than one short circuit) 114kA (Report No. PDL- 18.122.4) Cable OD= Ø36mm 156kA (Report No. ZKU-15-204) Cable OD= Ø38mm

IEC 61914:2009

Ellis Patents Flexi Strap – Specifications

Flexi Strap Part No. Weight g Trefoil Range Min mm Trefoil Range Max mm Flexi Strap Part No. Weight g Trefoil Range Min mm Trefoil Range Max. mm
FS24-34SDL 131 24 34 FS24-34HDL 165 24 34
FS30-41SDL 144 30 41 FS30-41HDL 185 30 41
FS37-47SDL 155 37 47 FS37-47HDL 202 37 47
FS43-54SDL 168 43 54 FS43-54HDL 221 43 54
FS50-60SDL 180 50 60 FS50-60HDL 238 50 60
FS56-67SDL 193 56 67 FS56-67HDL 258 56 67
FS63-73SDL 204 63 73 FS63-73HDL 275 63 73
FS69-80SDL 217 69 80 FS69-80HDL 294 69 80
FS72-85SDL 226 72 85 FS72-85HDL 308 72 85
FS82-95SDL 245 82 95 FS82-95HDL 336 82 95
FS92-105SDL 264 92 105 FS92-105HDL 364 92 105
FS102-115SDL 282 102 115 FS102-115HDL 392 102 115
FS112-125SDL 301 112 125 FS112-125HDL 420 112 125
FS122-135SDL 319 122 135 FS122-135HDL 448 122 135
FS132-145SDL 338 132 145 FS132-145HDL 476 132 145
FS-T001-4 Special Drive Socket FS-T001-4 Special Drive Socket

SDL- Standard Duty suitable for use with Vulcan+ cleats

HDL- Heavy Duty suitable for use with Emperor cleats

Flexi Strap Trefoil Dimensions

Flexi Strap Trefoil Dimensions


Ellis Patents recommend fixing VRT+ using one 10mm bolt for sizes 00 to 09, and one or two 10mm bolts for sizes 10 to 20.

Ellis Patents Cable Cleats

Ellis Cleats | Emperor | Vulcan | Atlas | Phoenix | Single Trefoil Quad Bundled Cables

Cable Cleats v Cable Ties

The Video produced by Ellis Patents provides compelling evidence of the need to ensure all cables are adequately supported and retained to cable containment to protect against the devastating effects of short circuit faults: 118kA Short Circuit Fault Current | 0.1 Seconds Duration | 480V Low Voltage Cables.