Are you really going to follow an advise given here? If so, I presume that you will also go ahead and install it yourself. Are you aware of the implications? are you aware of the possible consequences of a probable mistake?
If you have a 4.5 Megawatts power source, these questions should be directed to your utility company or at least to a KNOWN qualified engineer.
This is a forum for discussion where all technical information goes free of costs. One shouldn't decide on the basis of this discussion. They require to discuss with professional consultant and certification agency before implementation.
In this forum we don't know oneanother's qualification, work experience in detail.Some of us may be in govorning body of some standard agency, some may have vast and wide experience and seniority.But still this forum is where we clear our doubts and get views of some topics. We should be careful to implement anything we learn here.
Your load requirement is larger than available demand, at the least your maximum load should be 1500Kw at unity power factor. A fuse is meant to limit too much power from source reaching user point 'your cart is before the horse'.
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