Question

Can you help me with this situation and explain the questions?

Suppose an engineer designs a 120/240 Volt single phase power system for a restaurant including the indoor wiring circuits. He had some conversations with the restaurant owner prior to completing his final design but the owner was not very organized so only shared the other kitchen equipment technical specs by telephone. The restaurant hired an electrician to install the kitchen equipment and inside wiring. However, when the owner met with the electrician he found the kitchen oven to be a 480 Volt 3 phase equipment. The air conditioning system was also 3 phase 120/240 Volts. But the electric service to the building was single phase 120/240 Volts. That is, after the building is constructed and the restaurant equipment was installed, the owner sees only 2 wires from a single phase service rather than 3 wires for the 3-phase kitchen equipment and A/C needed. The manufacturer of the equipment says the 3 phase kitchen equipment totaling $7200 cannot be returned for single phase equipment. The owner showed the design drawing to the engineer and the bill of materials the engineer prescribed showed 3 phase oven and 3phase A/C but the outdoor service diagram showed single phase. Do you consider this an error of judgment by the engineer? Was there a communication breakdown? Who should pay for the incompatibility of the systems since matching them, up will require what kind of new electrical equipment? What equipment will be needed to power up 3 phase kitchen from a single phase service from the utility company? What other options are practical. Don't use theory, think practical. You will need to study single and 3 phase service diagrams and be creative to earn any points. Also think like a business-minded person not just a circuit designer. Money does not come easy for small business owners. What are the ethical implications here? What should the consequence be for the engineer? For the electrician and/or business owner? What is the public utility's role in a remedy?

Answer 1

In power system you have learnt the reactance diagram which is always drawn per phase rather than showing 3 phases separately to minimize complication and calculation for a balanced system.

The same has been done here that rather than drawing 3 phase power system the reactance diagram has been drawn which is always per phase circuit.(or you can say single phase circuit).

The electrician didn't understand that and hence he connected a signle phase supply to the appliances. On the basis of this try to answer the questions.