Cross sectional area current capacity

7029 dave said:

DW on the team then, well done, nice to see. Regards Dave.

Click to expand...

darkwood said:

Congrats... your the first to spot it to my knowledge ..was wondering when someone would see it

Click to expand...

Gardner said:

What am I missing lol?

Click to expand...

Gardner said:

You wouldn't happen to know what equation is used in other regs like the IEC? My understanding is, and I could be wrong, that table 4D5 and others were derived via thermodynamic equations made by the IEC.

Click to expand...

Gardner said:

How would you go about figuring the current carry capacity of 2.08mm2 copper conductor? In so far no reg tables have none standard size.

Click to expand...

Gardner said:

How would you go about figuring the current carry capacity of 2.08mm2 copper conductor? In so far no reg tables have none standard size.

Click to expand...

darkwood said:

Congrats... your the first to spot it to my knowledge ..was wondering when someone would see it

Click to expand...

Richard Burns said:

.........The current rating (ampere) using in the IEC standard is:

View attachment 29359
where Δθ [[SUP]o[/SUP] C] is temperature rise between ambient temperature and cable conductor temperature, W[SUB]d[/SUB] [W/m] is dielectric loss of cable insulation, T1, T2, T3 [K.m/W] are equivalent thermal resistances calculated from the cable material’s thermal properties, T4 [K.m/W] is the cable external thermal resistance, R[SUB]ac[/SUB] [Ω/m] is the AC electrical resistance of the cable conductor at maximum temperature and λ1 and λ2 are the ratio of losses in the metal sheath to total losses in all conductors and the ratio of losses in the armouring to total losses in all conductors, respectively.

Click to expand...

Richard Burns said:

I would agree with the above posts about cable sizing too many variable in standards compliance and cable design.

However this webpage seems to discuss the methods used in IEC60287. I feel it is not worth working it out when the standard cables have been calculated (probably well on the side of caution!) for you.

Edit just found this
IEC METHOD
IEC 60287 provides method for calculation of current carrying capacity of cable for different design parameters of cable (cross section, thermal resistivity, thickness of layer … etc.) as well as for different environment (ambient temperature, soil condition, depth of cable, spacing of phases … etc.).The current rating (ampere) using in the IEC standard is:

View attachment 29359
where Δθ [[SUP]o[/SUP] C] is temperature rise between ambient temperature and cable conductor temperature, W[SUB]d[/SUB] [W/m] is dielectric loss of cable insulation, T1, T2, T3 [K.m/W] are equivalent thermal resistances calculated from the cable material’s thermal properties, T4 [K.m/W] is the cable external thermal resistance, R[SUB]ac[/SUB] [Ω/m] is the AC electrical resistance of the cable conductor at maximum temperature and λ1 and λ2 are the ratio of losses in the metal sheath to total losses in all conductors and the ratio of losses in the armouring to total losses in all conductors, respectively.

Click to expand...

darkwood said:

This is because its under different regulations and the cable standards are also manufactured to differing regulation too, we have our own BS standards we follow and the cable we buy is manufactured to either EU or BS requirements.

Click to expand...

amlu said:

when i heard of a american cable been mentioned i would open a awg table and look up for an answer...
15/20/25 depending on insulation used.
https://en.wikipedia.org/wiki/American_wire_gauge

Click to expand...