Effect of Frequency on Power Cable

Ask the manufacturer.

I am 99% sure performance is the same.

So you haven't made the telephone call either.

No, I cannot tell you if the current carrying capacity will be different at 60 Hz instead of the rated 50 Hz. I do not know enough about how you are using this cable. I will say that for there to be a noticeable difference you have to be doing a very atypical job with this cable.

Ohms law does not apply here. Nowhere in the equations cited is frequency a variable. However, the resistance of the conductor does change with frequency if one considers the skin effect. From the cited Wikipedia section:

Formula

The AC current density J in a conductor decreases exponentially from its value at the surface J_S according to the depth d from the surface, as follows:

where δ is called the skin depth. The skin depth is thus defined as the depth below the surface of the conductor at which the current density has fallen to 1/e (about 0.37) of J_S. In normal cases it is well approximated as:

.

where

ρ = resistivity of the conductor

ω = angular frequency of current = 2π × frequency

μ = absolute magnetic permeability of the conductor^[1]

So one of the possible scenarios that frequency will change the parameters of this cabling is the skin effect. As I said earlier, we know next to nothing about the application of this cabling. We certainly do not know what diameter size of a conductor was chosen to know if a skin effect is even relevant.

Getting back to the OP. The only thing we do know is the cabling type of HV XLPE. This is High Voltage cabling used in power distribution. This cabling is designed to be used in places that amateurs should never enter. The members of CR4 maybe informative to you in explaining anything in this realm but we cannot be your authority on any critical questions. You should get your answer from someone with authority in your organization to use this cable. A simple e-mail to your staff engineer asking "The XX mm conductor diameter HV XLPE cable we have for this 60 Hz job at NNNNN is actually rated for 50 Hz operation. I might be just overly cautious but do we need to reconsider this cable selection?"

I will be surprised if this cabling must be changed, but I do not make that call.

You're right. I somehow confused V with f. That's why I never do my own plumbing.

I un-did the GA.

Without going to a lot of trouble to check, I'm fairly sure the skin effect only becomes significant at frequencies way above 50 - 60Hz.

Actually, you don't have to go through too much trouble at all. The Wikipedia article states in the first paragraph "At 60 Hz in copper, the skin depth is about 8.5 mm. " So unless the copper conductor is more than 17mm in diameter there is no appreciable skin effect. However, for all we know the OP may have a 25mm diameter cable and the skin effect will be a factor.

OK thanks, but that does surprise me. I hadn't opened the Wiki thing and assumed you had to find the figures for ρ, μ etc and work it out.

Electric cables have a max frequency rating typically well above the 50/60hz level...The cables are tested at 50hz and max current to test dielectric strength, not current carrying ability....

I use cable, the same cable at 45 to 70Hz.. not noticed noticed any change it the performance. I do however have to take into consideration the length for the voltage drop (I use 3km of cable at a time) and temperature.

As stated, check with the cable maker. One thing that might affect the cable would be the number of joints or splices you have, if used. Harmonics tend to have an unusual effect on spliced cables. Something to watch for and ask for further info if not sure!

The type of cable mentioned, XLPE, is only the insulation, which has nothing to do with frequency. The CROSS SECTIONAL DIAMETER and NUMBER OF STRANDS may have a slight effect on current carrying capacity once the line frequency is extremely high, i.e. 400Hz, because of skin effect but there is no noticeable difference between 50 and 60Hz operation, in fact I'm surprised to see it even mentioned in the specs.

There have been studies on the effects of HIGH frequency on XLPE cable, but that is way above anything you are talking about here, I.e. 1GHz.

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=963504&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F7627%2F20802%2F00963504.pdf%3Farnumber%3D963504

I'd be surprised to see that listed as well, except in the case of a very cheap product only being tested in a limited fashion...and sold under those tests..."guaranteeable".

Otherwise, the only difference between 50Hz and 60Hz power would be the RMS and peak differences. Minor at best/worst on paper...barely measurable in the real world.

It will work but about the current carrying capacity it need to be checked since frequency plays an important role in the current carrying of a cable due to a condition called skin effect. On the other side since its AC current remember that reactance depends on frequency as well so the voltage drop will be different.