wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
1) Say I give you a black box that performs as a 240V 2-wire to 120/240V 3-wire isolation transformer. Inside could be a single core transformer with a split secondary, or two separate 240V:120V transformers, with the primaries in parallel but the secondaries in series in the proper way. Is there any external testing you can do to determine which transformer arrangement is inside?
2) Suppose I connect 10A constant current loads L1-N and L2-N, with the L1 load 60 degrees lagging power factor, while the L2 load is 60 degrees leading power factor. So the component of the current in phase with the voltage is 5A for each load, but the reactive currents are in opposing directions. Is the primary current (as measured outside the black box) simply 5A in phase with the voltage?
Thanks,
Wayne
2) Suppose I connect 10A constant current loads L1-N and L2-N, with the L1 load 60 degrees lagging power factor, while the L2 load is 60 degrees leading power factor. So the component of the current in phase with the voltage is 5A for each load, but the reactive currents are in opposing directions. Is the primary current (as measured outside the black box) simply 5A in phase with the voltage?
Thanks,
Wayne