Tuesday, June 27, 2017
For the past 40 years most industrial facilities operating between 480V and 5kV were designed with 3 phase 4 wire systems. This addressed the concern over transient over-voltages and allowed for neutral loads but these loads are typically 10% or less of the total load and designing a 4 wire system just to accommodate single phase loads adds cost. In addition to higher cost there is higher risk as 4 wire solidly grounded systems have the highest probability of arc flash. Designing a 3 phase 3 ...