We have a 230V-3P-3W system. We are working on a design build project for a renovation to an existing commercial building. The owner wants an elevator, so we had the electrician double check the voltages. The electrician measured 280V L-L and 160V L-G. After some discussions, we decided to call the power company and have them verify our system. They explained that they are using three separate 138.5/277V xfmrs connected like a wye, but used as a delta for the 240V-3P-3W system. The phasor calculation makes sense 138.5V*sqrt(3)=240V
Did my electrician measure the L-L voltage wrong or use the wrong meter (should use a 3phase meter)? 280V appears to be higher than normal, but the power company insists everything is normal.
As it turns out, they can use the same 138.5/277V stock xfmr for a 277/480V-3P-4W system (277V*sqrt(3)=480V).
We want to convert this system with a 3-phase 15kVA 240V-120/208V xfmr to connect our traction elevator. This makes sense on paper, but has anyone done this before?
Thanks, Blaine
Did my electrician measure the L-L voltage wrong or use the wrong meter (should use a 3phase meter)? 280V appears to be higher than normal, but the power company insists everything is normal.
As it turns out, they can use the same 138.5/277V stock xfmr for a 277/480V-3P-4W system (277V*sqrt(3)=480V).
We want to convert this system with a 3-phase 15kVA 240V-120/208V xfmr to connect our traction elevator. This makes sense on paper, but has anyone done this before?
Thanks, Blaine