Hi All,
First of all apologies for the potentially novice sounding question believe it or not I’ve been a qualified electrician for 10 years but I’ve always worked cards in so calculations have not been something I’ve ever considered I just install the sizes on the spec however I now have to design a small upgrade so looking for clarity on something.
I am installing a 3 phase sub mains to a 24 single or 8 3 phase ways board.
The load on the 3 phase DB is going to be entirely single phase and although balance is going to be as close as possible it will not be perfectly balanced.
I have a total of 38kw of load which will be split 14-12-12 across L1-L3.
Total load is 165A or thereabouts so the question is does the 3 phase cable current carrying capacity refer to the total load (165) or the per phase (approx 55)
Also with that in mind is the 3 phase load then considered 165A or is it 52A applying the calculation to 38kw?
For this I’m not taking into account volt drop or anything I have an app do actually do the calculations but I want to understand how it works.
Thanks in advance
First of all apologies for the potentially novice sounding question believe it or not I’ve been a qualified electrician for 10 years but I’ve always worked cards in so calculations have not been something I’ve ever considered I just install the sizes on the spec however I now have to design a small upgrade so looking for clarity on something.
I am installing a 3 phase sub mains to a 24 single or 8 3 phase ways board.
The load on the 3 phase DB is going to be entirely single phase and although balance is going to be as close as possible it will not be perfectly balanced.
I have a total of 38kw of load which will be split 14-12-12 across L1-L3.
Total load is 165A or thereabouts so the question is does the 3 phase cable current carrying capacity refer to the total load (165) or the per phase (approx 55)
Also with that in mind is the 3 phase load then considered 165A or is it 52A applying the calculation to 38kw?
For this I’m not taking into account volt drop or anything I have an app do actually do the calculations but I want to understand how it works.
Thanks in advance
- TL;DR
- Does the current carrying capacity of 4 core cable refer to overall or per phase when feeding single phase loads.
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