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Topic Title: CCC
Topic Summary: Yellow 6mmsq insulated eye crimp
Created On: 05 December 2012 12:05 PM
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 05 December 2012 12:05 PM
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zeeper

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Joined: 11 July 2008

So whats the CCC of these type of eye crimps most things electrical have it printed some where , but having trouble finding it with crimps.
 05 December 2012 12:21 PM
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AJJewsbury

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I don't think I've ever seen the current rating of crimps explicitly stated either. Would it be unreasonable to assume it would be no less than that of the maximum cable it could accommodate (at 70 deg say for PVC insulated crimps)?
- Andy.
 05 December 2012 12:21 PM
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OMS

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Going from memory, "yellow" lugs have a CCC of 48A - which usually exceeds the nominal CCC of insulated 6.0mm2 cable which is the biggest size for the lug.

Manufacturers data often states either equivalent CSA in mm2 with a temperature limit - or gives you amperage at the limiting temperature (usually 85C for insulated lugs)

Regards

OMS

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 05 December 2012 01:38 PM
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MrP

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Yah but if you wedge 3x 1.5 in your CCC goes out the window

MrP14days
 05 December 2012 01:47 PM
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OMS

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Originally posted by: MrP

Yah but if you wedge 3x 1.5 in your CCC goes out the window

MrP14days


LoL - yes, well - I suppose it does

Regards

OMS

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Failure is always an option
 06 December 2012 03:34 PM
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zeeper

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funny because my reply was going to be well I normally I use copper tube crimps on power circuits. However data for these seems to be hard to find as well.

Normally every thing we use we ensure its made to a relevent standard and is rated correctly for what its being used for. Just a bit funny crimps data is not easy to come by.
 06 December 2012 03:37 PM
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zeeper

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Yah but if you wedge 3x 1.5 in your CCC goes out the window


But pushing 3 conductors into the crimp would not comply with B7671 anyhow.
 06 December 2012 04:12 PM
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OMS

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Well, you'll be working to BS 7727 won't you Zeeps - so this bit will be familiar to you:

7 Current rating
Current ratings are dependent upon the conductors in use, the environment and the permitted temperature rise. Correctly designed copper compression terminals and splices, correctly applied to annealed high-conductivity copper conductors will have at least as high current ratings as those conductors. However, with disconnect connectors, which are made from copper alloy, the current ratings are governed by different criteria and advice should be sought from the supplier or manufacturer.


The crimps will either have markings on the palm or barrel or provided in/on the packaging - these will relate to the conductor size and limiting temperature rise.

As I said, typical 6.0mm2 crimps (yellow) will be about 48A when operating to 85C

Regards

OMS

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Failure is always an option
 06 December 2012 04:43 PM
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rocknroll

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Generally the standard for the coloured 415/240V crimp terminals are:

Red - 0.5 - 1.5mm² - Max rating 20A
Blue - 1.5mm - 2.5mm² - Max rating 30A
Yellow - 4.00mm - 6.00mm² - Max rating 50A

As was noted the rating basically matches the cable size, at one time there were crimp terminals rated at 50V for automotive applications and crimp terminal rated at 415/240V but I suspect that now because of tooling costs it is much more economical to make one type to suit all.

In the eighties crimp terminals were starting to be used in their abundance in place of conventional termination methods and in order they could be used in the nautical and aviation field they needed to be certified by Lloyds, so the R & D Laboratory at County Wakefield, Ireland was given the task of testing crimp terminals and the tests were;

Electrical:
1000 heat aging cycles lasting approximately 50-60 minutes. Conductor temperature to reach 130oC. 3 short circuits with conductor temperature rise from ambient to 250oC: in 1 to 3 seconds. Assessment based on resistance changes and temperature measurements.

Mechanical:
Mechanical tensile tests (40 N/mm² Al) (60 N/mm² Cu) to evaluate mechanical integrity.

Both copper and aluminium solid and stranded conductors were used.

So the moral of the story is if the crimp terminals are not going to be subjected to temperatures in excess of the above and you are not going to hang your washing on the cables then there is no problem.

Whilst crimp terminals have been deemed an excellent method of termination there are a couple of down sides which are attributed to installation methods and not the crimps, the first one is termination in most cases where crimps have failed is because conductors have been scored when stripping the cable and any lateral movements have caused slight fractures and the second one being the incorrect tools like sidecutters, pliers etc have been used instead of the proprietary tools which apply a set number of crimps at the correct place with the correct minimum torque.

Have you got a calibration certificate for your crimping pliers.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------

Edited: 06 December 2012 at 04:50 PM by rocknroll
 06 December 2012 05:09 PM
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Avatar for OMS.
OMS

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LoL - are you sorry you asked now Zeeps -

OMS

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Failure is always an option
IET » Wiring and the regulations » CCC

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