PE (Electrical), NABCEP certified
- Austin, TX, USA
- Electrical Engineer - Photovoltaic Systems
Say you have two 100kW 3P inverters, one connected wye and the other connected delta, both running at capacity. You put your clamp ammeter around the output conductors (one at a time, of course) and take measurements. Do you see a difference in current between the conductors from the wye inverter and those from the delta inverter? I don't think you will. There are inverters that can be connected either way and they don't quote different output current or required OCPD for the different connections.Do we agree on the following? Three single phase inverters connected to a three phase system as in post #14. Say its a regular 208 service. Inverters are thus 208V, say 32 amps. That is 20KW total of inverters (208)(32)(3). Three phase power is W=(V)(I)(1.732) so current is 55.5 A or 1.732 times the inverter or phase current. The currents I am referring to as being different are the 32 amps and the 55.5 amps. (phase and line respectively). Are we each talking about different currents or points of measurement?
It's why I mentioned semantics; the current in those conductors is what I know as "phase current" and it's always the same as line current for a balanced 3P circuit in the same way that the current in both conductors in single phase 240V is the same as the line current; maybe the term means something else to you.