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Loading Performance

The primary role of Cablofil® is to be an efficient and universal cable support.  The mechanical performance of all products and accessories is tested to the stringent requirements of the international standard IEC 61537 and NEMA VE-1/CSA 22.2

For complete carbon steel destruction load testing results click here.

For complete carbon steel deflection load testing results click here.

Cable Tray Load

Cablofil's wire mesh cable tray load capacity is designed to exceed the cable load allowed by the national electric code(NEC, NFPA70).  Since the load is distributed uniformly, it is expressed in DaN/m or lb/ft.

Listed below is the maximum cable capacity and recommended load for Cablofil wiremesh tray on 8' support spans.  Cablofil recommended cable load is higher than the maximum allowable cable fill per NEC on 8' support spans with less than .5" of deflection.

 

 Maximum Allowable Cable Load (per NEC 392)

Cable Type

Tray Size 

Cat6a1

Cat5e2

Branch MC3

Feeder MC4

Cablofil Tray Load Capacity

 

           

 

 

 

  

   

 

MAX 

Cable Load

MAX

Cable Load 

MAX 

Copper Cable Load 

MAX 

Copper Cable Load 

  Alum Cable Load

 

Cable Load 

 

 

Cable Qty

(lb/ft)

Cable Qty

(lb/ft)

Cable Qty

(lb/ft)

Cable Qty

(lb/ft)

(lb/ft)

(lb/ft)  

2x12

125

4.5

426

8.5

54

7.4

8

12.7

8.4

 20

2x24

251

9.0

852

17

108

14.7

16

25.4

16.8

 32

4x12

248

8.9

844

16.9

54

7.4

8

12.7

8.4

 44

4x24

497

17.9

1689

33.8

108

14.7

16

25.4

16.8

 48

6x12

357

12.9

1213

24.3

54

7.4

8

12.7

8.4

 50

6x24

715

25.7

2427

48.8

108

14.7

16

25.4

16.8

 52

 

Cable Dia(in) Copper Cable Weight(lb/ft) Alum Cable Weight(lb/ft)

1

0.35

0.036

 

2

0.19

0.02

 

3

0.53

0.137

 

4

1.49

1.59

1.05

8' Span deflection limited testing (0.5" deflection) Safety Factor 5

Other manufacturers may list higher load values with excessive deflection and low safety factors, but these load values have no practical meaning since the cable load cannot exceed 50lb/ft per the NEC.

 

 

Deflection vs. Destruction

Cablofil is unique in its loading performance due to its wire mesh pattern.  If an excessive load is applied to Cablofil Tray, its wire mesh structure does not break under load, but deflects gradually.  Typical Cablofil safety factor is 4-5 using deflection based maximum load ratings(IEC).  Typical ladder tray safety rating is 1.5 when tray is tested per NEMA VE1.

A tray that would simply fail instead of deflect could result in severe injuries or major damage.

In the event of overload, a mesh structure becomes deformed like a hammock.  It deflects but does not break.

 

IEC 61537 Test Results

The standard imposes a deflection of 1/100th of the span.  Cablofil®, being more demanding, has doubled the requirement to 1/200th.

For example a span of 6.5 ft (2 m) the IEC standard requires a deflection of .8 in (20 mm), whereas Cablofil ® deliberately limits it to .4 in (10 mm), resulting in a more aesthetically pleasing installation.


Permissible load for maximum sag = L/200 on the intermediate span, splicing at 1/5th of the span.



Each Cablofil® reference has been tested in the required configuration.  The resultant deflection is measured in the middle of the span with a splice at 1/5th of the span.

 

Test configuration

Splicing L/5
L=Span
 

 

Splice Location

To optimize the performance of the cable tray, the choice of couplers is as important as that of their positioning in the span. Cablofil® couplers are designed and tested for high mechanical and electrical performance.

It is important to follow these recommendations to take full benefit of splice design: 

General case valid for all spans

Optimum

(100 % Performance)

Placing the span at 1/5th of the span is the best solution

Possible

(70% Performance)

Mid-span splice reduces load capacity by 30% 

Prohibited

Never put the support under the splice

Cablofil® 6.5 ft. (2 m) Span

 

6.5 ft (2 m) spans are recommended without the splices being positioned at the supports or in the middle of the spans.

To obtain this result, the first span is deliberately limited to 5 ft. (1.5 m), then the supports are placed approximately every 6.5 ft. (2 m). The splices are therefore always 1 ft. (0.5 m) from a support.

 

Finite Element Analysis(FEA) is used to optimize wire size and designed to maximize strength.


 



Support Load

The brackets are characterized by their permissible loads (in lbs).

All Cablofil® supports are tested and conform with the standard NEC Article 392, NEMA VE-1, IEC 61537.


The safe working load (SWL) as defined by the standard is the lowest value of either:

  • The load creating a deflection of L/20 at the end.
  • The breaking load divided by 1.7, if the deflection at L/20 is not reached.
 

Change of level and direction: The support must be placed within 1/5th span of the cable tray fittings. It is recommended to place supports at the start and end of 90o bends. For bends of large radius, place an extra support in the middle of the fitting.