I'm a student majoring in Architecture one of my class, Building Utilities, needs me to survey a high rise building. In my team, we divided the parts bc there are so many and one of my job is to electricity. Can someone explain to me the meaning of phase, R.P.M, power factor, and (especially) their respective units/numbers from this picture
'Phase' has no units: it is merely a number, in this case 3. It is the number of different live supplies coming out of the generator. On the blue label in your picture, to the right of the word PHASE there is a small clear panel. The 3 followed by a greek letter 'phi' is the number of phases. Then there is '4 W'. This tells you that the generator is wired in 'star' layout with a total of four wires. Three carry the live supplies and one is a neutral wire. Your building will have a lot of wall outlets and some heavy loads; for example, the motors for the elevators. The wall outlets are single phase, connected to only one of the phases from the generator. Heavy loads are often connected to all three phases. 'R.P.M'. is revolutions per minute , which means 'how many times the rotating part of the generator rotates in one minute'. 'Power factor' again has no units. An explanation of what it is? I'll come back to that later (or someone else can) .
Phase is 3Φ 4W, which means three phase, four wires. Three wires for each of the phases and one wire for the neutral. There are two ways to connect 3 phase generators, ywe which looks like the letter Y (3 or 4 wires) or delta which looks like a triangle (3 wires). Voltage is 380/220V, which means a wye-connected generator with two voltages available. For heavy loads like heating and motors, a line voltage of 380V, measured across two of the phases, is available. For light loads like lights and outlets, a phase voltage of 220V, measured across a phase to neutral, is available. The use of 380V means smaller conductors can be used. When the generator spins at 1500rpm (revolutions per minute), the output frequency is 50Hz. N 120 f / P P 120 f / N 120 * 50 Hz / 1500 4. The generator has 4 poles per phase. Since it is an even number, the generator is a synchronous generator. Prime is the Apparent Power S in kVA that the generator set is capable of providing for an unlimited number of hours per year. In this case 600kVA. But as a Standby Generator (Emergency) operated less than 500 hours/year, the apparent power S is 660kVA. Current is 1003A. This is the rated current that can be supplied to the building at 380/220V. S √(3) V_LINE I_LINE I_LINE S / (√(3) V_LINE) 660kVA / ( √(3) * 380V) 1003A Power factor 0.8 lagging, which means at worst case the loads attached to it can have a power factor greater than 0.8. Power factor P / S. P S * pf 660kVA * 0.8 528kW The Real Power P or W loads the generator can supply are 528kW. So it can supply 5280 100W light bulbs, for example. If power factor is 1, 660kW could be supplied. There should be an electrical switchboard close to the generator, which will have labels showing how power is fed throughout the building. Everything else is specific to the device (Model, Serial, etc). Probably too much information for you, but when you are trying to understand something too much is better than too little.
