Very interesting thread here....a few years back "harmonics" was the buzz word in the trade, you could'nt swing a dead cat without hitting an article about it, fixtures & equipment started comming out with a THD rating. Courses started popping up , and of course, every trade mag followed suit...
Originally posted by resqcapt19: Electrican, Were the circuits in your last post "3-wire" or "3-phase"? My understanding is that there is no neutral overloading or harmonic problems with nonlinear loads on 120/240 single phase systems. Don(resqcapt19)
The circuits are 3 phase 120/208. Our temp. solution is to rewire the lab w/ dedicated neutrals. Only problem is this pushes the problem to the service conductors feeding the panel that feeds the equipment.
Electician, Don't forget that when you use individual grounded conductors for each circuit, all of the conductors are current carrying and derating in Table 310-15(b)(2)(a) will apply. Don(resqcapt19)
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