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Question about electrical wiring

Enthuware Software Support
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I need to wire an electric water heater that consumes 3kW of power and I am trying to figure out appropriate size of flexible multi-strand pvc insulated copper cable. I understand that if the input voltage is 200V, current flowing through the cable will be 3000/200 = 15A.

Now, as per the attached current capacity guide of the cable manufacturer, I should use 2.5 sq mm thick cable, which is rated to carry 18A. So far so good, I think.

What I am confused about is the column header that says "Current carrying capacity # of 2 wires, Single Phase". What do they mean by "2 wires"? Does that mean the current capacity of one cable is only 9A?

I checked a couple of other cable manufactures' rating sheets as well and they say the same thing.

Any thoughts?

Not sure why the image is not showing up. Here is the link http://postimg.org/image/bkprfqaox/
[Thumbnail for current-guide.png]
Ranch Hand
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MS IE Linux
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I am not an electrician, but I was helping with electrician works in past, so I will try to help. I do not take responsibility if something blows up!

Two wire single phase cable is a cable for AC power, one power wire and one neutral wire. In comparison, a four wire three phase cables come with 4 wires, 3 power lines and one neutral.

In your case, the specs are given for two wires, so for an "entire cable". The cable you suggested should be able to carry 18A.

Remember about proper grounding!
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