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Cable current rating advice

Former Community Member
Former Community Member
Hi all, I would like to verify something with respect to current carrying capacity of cable. Specifically vehicle single core DC circuits.


Looking at 16mm wire not worrying about voltage drop. manufacturers are ratting this at 110A and on a forum I subscribe to people have been advised 125A is ok.


The cable is rated at 70 deg as shown on the suppliers site linked below.

16mm supplier


Am I wright that this comes under 

Table 4D1A


Single-core 70°C Thermoplastic Insulated Cables, Non-Armoured, with or without Sheath


Reference Method C (clipped direct) This will be between battery to battery not in any conduit or insulation


So is rated as 87A


I would be interested in your advice as it has been several years since I used these tables
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  • 0
    Just to check if I am reading Mikes chart correct at 80amps and 30 deg ambient temp the core temp would be 62 deg is this correct


    yes - you go up from 80A to the diagonal line, and read across to 32 or 33 temperature rise. Add that to you ambient air temp to get the copper core temp.

    Do realise it is not quite right, as 6AWG is not quite your 16mm2, more like 14mm2, not a European size.


    The cable you linked to in the original post is rated at 70C, but I assume the temperature they are quoting the ambient at which the core temp is right on the limit for the quoted rated current - so at 100A perhaps 50 degree rise from a 70C ambient takes the core to 120C or so.Which is certainly pushing it if you'd like a long lifespan, and not good for anything near the cable either.

    If the insulation failed at a lower temp, then the current and temperature ratings would need derating .

    M.
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  • 0
    Just to check if I am reading Mikes chart correct at 80amps and 30 deg ambient temp the core temp would be 62 deg is this correct


    yes - you go up from 80A to the diagonal line, and read across to 32 or 33 temperature rise. Add that to you ambient air temp to get the copper core temp.

    Do realise it is not quite right, as 6AWG is not quite your 16mm2, more like 14mm2, not a European size.


    The cable you linked to in the original post is rated at 70C, but I assume the temperature they are quoting the ambient at which the core temp is right on the limit for the quoted rated current - so at 100A perhaps 50 degree rise from a 70C ambient takes the core to 120C or so.Which is certainly pushing it if you'd like a long lifespan, and not good for anything near the cable either.

    If the insulation failed at a lower temp, then the current and temperature ratings would need derating .

    M.
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