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Large HP VFD output on switcboard bus

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    Large HP VFD output on switcboard bus

    I need to connect the output of a large regen. VFD (2,600HP, 690V) to a switchgear bus in order to direct power (via PLC controlled breakers) to either 1) a large M-G set or (2) a large motor test stand...up to 2500HP @ 690V. Owner wants the ability to use the drive for either load.

    VFD rated output is as follows:

    I(max) = 3680A (10-sec at start)
    I(2N) = 2362A (Normal duty use, continuous base current, Overload cycle I(2N) 110% for 1-min / 5-min allowed
    I(2HD) = 1840A (Heavy duty use, continuous base current, Overload cycle I(2HD) 150% for 1-min / 5-min allowed

    I'm not an expert on drives (these are owner provided) Preliminary design is to use a 4,000A, IEC gear, 690V. Does anyone know of any concerns with this large VFD "non-sinusoidal" output on a swichgear bus?...or any considerations to be aware of for the circuit breakers?

    Note: This is a motor test lab....would never have a need for this in industry.

    So serious issues in that regard, should be fine. The nonlinear current would not be an issue if all you are doing is burning it off somewhere as a load.

    My concern would be if the MG set will have enough impedance for this though. Most regen drives need that, but that is a question for the drive mfr.
    __________________________________________________ ____________________________
    Many people are shocked when they discover I am not a good electrician...

    I'm in California, ergo I am still stuck on the 2014 NEC... We'll get around to the 2017 code in around 2021.