The apartment house electrical layout CAD drawing includes the single-phase sockets will be of the type with grounding and will be connected together with the boards to the earth well with TW - 4 mm conductor. Characteristics of the Single-phase System 2 wires 220 volts 60 Hz.cos All equipment and materials that are installed outdoors will be of the waterproof type the boards will be of the metal type to embed and communication conductors should not be installed less than 5 cm from lighting and/or force. dpwnload free electrical layout plan drawing download dwg file.