tri-rated cable

[Lee321]

if tri-rated cable will carry much more amps than conventional cable due to its "fine wire strands" why doesn't flex offer greater CCC than other similar sized 6491x for example?

 

[Evans Electric]

Its more to do with the type of insulation .

 

[Lee321]

Its more to do with the type of insulation .

yum right ah kid but trying to find CCC for flex is non existant

 

[PC Electrics]

Tri-rated's ccc is quoted at 105C. The insulation (plasticised PVC according to the Draka handbook) is able to stand this as a continuous temperature and this increased temperature in turn allows a higher current.

 

[PC Electrics]

yum right ah kid but trying to find CCC for flex is non existant

try table 4F3A for ccc and 3B for voltage drop

 

[Lee321]

looked there PC but thats very limited as the specs for flex is very varied

 

[PC Electrics]

looked there PC but thats very limited as the specs for flex is very varied

Not sure what you're getting at, that's the correct table for flexes.

For flexes greater than 4mm use table 4F1A

 

[Lee321]

Not sure what you're getting at, that's the correct table for flexes.For flexes greater than 4mm use table 4F1A

there are many specs of flex so how can it apply to all?

 

[PC Electrics]

The Draka handbook refers to these tables for all flexible cable types - the type of cable (eg arctic or heat resisting) doesn't alter the ccc.

H07RN-F for example tells you about the cable type and construction and the applications it's suitable for. 4F3A is used to determine ccc.

Get yourself on the Draka website and get a copy of the "Cable and Tables Handbook".

 

[Lee321]

yep your dead right, had a look at a few datasheets now

how strange tho that the higher temp rated cords don't carry anymore

 

[Lee321]

so if tri-rated (single core cable) is all to do with the insulation properties why is the core fine stranded?

as this is the first thing you notice when working with it then you have a gaze at CCC table for tri-rated and wrongly presume its due to the fine stranding

 

[PC Electrics]

so if tri-rated (single core cable) is all to do with the insulation properties why is the core fine stranded?as this is the first thing you notice when working with it then you have a gaze at CCC table for tri-rated and wrongly presume its due to the fine stranding

for flexibility

 

[Lee321]

for flexibility

yeah obviously but just seems to be the most significant change where as the tri-rated pvc properties being able to handle more heat are not available in standard strand configuration

only an observation btw

i.e when they set out to make a flexible cable they also made it with high temp insulation and able to carry more current.

 

[netblindpaul]

Peeps,

The "tri-rated" bit refers to it meeting British Standards, American Standards & Canadian Standards.

It is most common in machinery applications.

The fine strands make it more flexible and more immune to vibration damage.

I ALWAYS use it as the final connection to vibrating equipment, fixed rotating machinery, electric motors etc.

6491x is simply not suitable for the frequencies of vibration imparted in it when used in flexible conduit to rotating machinery.

Neither really is SWA as it has the same strand configuration (typically) as 6491x.

Mind for tri you do need to use ferrules don't clamp it straight into terminals!

The insulation is also 105 degrees celsius which is NOT covered in 7671, the max there is 90 celsius, so it is not really covered.

Why? Because it is not considered a material used in fixed wiring installations, the fixed wiring equivalent is 6491x.

Tri is not needed as fixed wiring installations are not subjected to the same levels of vibration and movement that "tri" is meant to withstand.

I keep and use rolls of the stuff for machinery building and repair, it may be covered in 60204, but I'd have to check.

Late now.

ATB

Paul.

Guinness

 

[ProDave]

It's over 7 years since I worked on industrial control systems, so forgive me if my memory is a bit vague.

I always thought "tri rated" meant that the cable complied with more than one international specification.

By using tri rated cable in our control cabinets meant we could sell the same design to Europe, Japan and the USA, rather than having to source cable approved for each market and manufacture specific cabinets for each destination country.

Therefore the fact it's "tri rated" in itself says nothing about it's CCC rather it tells you what markets it's approved for use in. Of course for a cable to be tri rated must mean it meets all the different international specifications, and if (as it does) one of them requires a high temperature insulation, then that is what it will have.

I think the key here is the 105 degree insulation rating, which will give it a higher CCC compared to say UK spec conduit singles, which you wouldn't be able to incorporate into a control cabinet and sell it in the USA for instance.