### Standards - Scenario 2

This post is inspired by the 2017 Philippine Electrical Code (PEC) Appendix D Example D12 (Voltage Regulators, Three-Phase). SITUATION A three-phase automatic voltage regulator (AVR) rated 30 kVA, 60 Hertz, 350-530 Volts input, 230 Volts output needs a feeder circuit from the main service panel. The AVR is installed in an air-conditioned data center with raised floors, and the conduit for electric conductors shall be run underneath. The wires to be used are made of copper conductors, with insulation rated for 75 degC operating temperature and of type THW (Thermoplastic, Heat-resistant, for Wet location). The raceway for the circuit is a rigid PVC Schedule 80 conduit. What size of 3ph circuit breaker, wires, and raceway are needed? ANALYSIS 1.) ONE-LINE DIAGRAM i,avr,1L ---> o|---V,msp,LN---V,avr,LN---|> 2.) CIRCUIT CALCULATIONS 2.1.) Kirchhoff's Voltage Law, LN: -V,msp,LN + V,avr,LN = 0 V,avr,LN = V,msp,LN 2.2.) Power equation, 3ph: S,