I = W/E. Amps = Watts/Volts = 6500/240 = 27 amps. A #10 copper conductor with an insulation factor of 90 degrees C is rated at 30 amps. If the load is continuous the conductor can only be loaded to 80% of its capacity. 30 x 80% = 24 amps which is too low for your load. Move to the next size wire which is a #8 which is rated at 40 amps x 80% = 32 amps. As long as no long distance runs are involved this wire size will work well.
If a load were only 240 volt on a single phase 240v system with a center tapped transformer the neutral conductor would carry no current.
If I have 1 KW In 3 Phase it will give 1.54 A and In single phase it will give 4.6 AFor cosF 0.9V 415 3 phV 240 1 phIt seems the reason is because the current is carried on more wires. Also, remember that if wattage stays constant, then as voltage increases, current decreases.AnswerIt really depends on the load. Are you assumining the three-phase load to be the same as the single-phase load or, as it is likely to be in practice, three times the value of the single-phase load?But, in either case, the single-phase current will not be double the the three-phase (line) current!The equation for the load current supplying a single-phase is: I = P / (E x power factor)The equation for the line current supplying a balanced three-phase system is: IL = P / (1.732 x E x power factor)If you insert real figures into these equations, (240 V for the single-phase voltage and 415 V for the three-phase line voltage) then you will find that, when the three-phase load is threetimes that of the single-phase load, the supply currents will be exactly the same. On the other hand, if you assume that the three-phase load is exactly the same as the single-phase load, then you will find that the three-phase line current will be one-third that of the single-phase current.
Any load that needs three legs from a three phase system can not be considered single phase. Single phase from a three phase system only needs a connection to two legs.
The difference between a single and a three phase online UPS is a 3 phase can supply a 100% unbalanced load on its output without affecting its performance. A single phase cannot supply a 100% unbalanced load on the output without affecting its performance.
A single-phase load can be connected to a three-phase supply either by connecting it between any pair of line conductors or, for a three-phase, four-wire, system, between any line conductor and the neutral conductor -providing, of course, that the resulting voltage matches the requirement of the single-phase load. This is quite a common arrangement, and the utility company will always try to maintain a reasonably 'balanced' load by connecting a number of single-phase loads between alternate line conductors (e.g. A-B, B-C, C-A, etc., or A-N, B-N, C-N, etc.). So, to return to the question: 'What is the effect on a three-phase system if a single-phase load is connected to it?', the answer is that the three-phase system can normally deal with it without any problem.
If a load were only 240 volt on a single phase 240v system with a center tapped transformer the neutral conductor would carry no current.
If the 240V 3-phase service is 240V phase-to-phase, then you can get 240V single-phase by simply picking two phases (poles, as used in the question) and connecting the load across them. This is simply one third of a standard delta connection. If you need 120V/240V split phase, i.e. with a neutral, as used in residential services, you will need a transformer. If the service is actually a four wire "quadraplex" service, however, you will probably already have that 120V/240V with neutral connection phase available. In this case, you will need to pick the two phases correctly in order to get the proper 120V service half.
..the questions does not say wether the 30kVA transformer is 3 phase transformer or single phase transformer..but it is implying that a single phase welding load at 16A per phase is to be connect to it, it is assumed then that the transformer is 3 phase transformer..we assume load is rated 240V.. ..though not much details is given about the transformer voltage specs. but if is rated 3 phase 415/240V, the approx full load current per phase is given by 30KVAx1.3912=41.736A.. ..but if the transformer was rated single phase 240V say, the approx full load current FLC=30000/240V gives 125ampers.. ..if you further devide the FLC by the intended load current.. ..Recommended no of welders per for a 3 phase 415V transformer and assuming single welding sets =41.736/16=2.6..so you can connect max two welding sets to this transformer per phase,..max 6 weld sets can connect at an approx load factor of 76%.. ..for the single phase transformer, FLC/16=125/16, gives 7.8 but is also recommended not to connect more than 6 welding sets to such transformer for the same reasons..
I'm sure this isn't what you want to hear, but you probably need to ask an electrician familiar with your service and what you want to connect. As a general answer, you can connect a 240v line to line resistive load like an electric water heater to any 240v source. If you also need the 240v to have 120v line to neutral, like a 240v electric stove that contains a 120v clock and oven light, then its possible if the 3 phase power is connected in a "high delta" configuration, and you connect to the correct leads. If you have a high delta service and want to ignore the 3-phase power service and wire most or all of the loads in the building as a single phase load, the utility may have to be consulted.
torque load, generation load, power correction load
If I have 1 KW In 3 Phase it will give 1.54 A and In single phase it will give 4.6 AFor cosF 0.9V 415 3 phV 240 1 phIt seems the reason is because the current is carried on more wires. Also, remember that if wattage stays constant, then as voltage increases, current decreases.AnswerIt really depends on the load. Are you assumining the three-phase load to be the same as the single-phase load or, as it is likely to be in practice, three times the value of the single-phase load?But, in either case, the single-phase current will not be double the the three-phase (line) current!The equation for the load current supplying a single-phase is: I = P / (E x power factor)The equation for the line current supplying a balanced three-phase system is: IL = P / (1.732 x E x power factor)If you insert real figures into these equations, (240 V for the single-phase voltage and 415 V for the three-phase line voltage) then you will find that, when the three-phase load is threetimes that of the single-phase load, the supply currents will be exactly the same. On the other hand, if you assume that the three-phase load is exactly the same as the single-phase load, then you will find that the three-phase line current will be one-third that of the single-phase current.
There is no such thing as a two phase load any more. Any two legs from a three phase system are classed as single phase. If this single phase load is connected across the generator it will induce an imbalance in the output voltages of the generator. This is one reason that single phase loads on a three phase generator should be shifted around to find the best possible balance.
To obtain a single-phase supply from a three-phase supply, the single-phase load must be connected either (a) between any pair of line conductors, or (b) between any line conductor and the neutral conductor. Of course, the voltage obtained from either of these connections must match the voltage rating of the load.
Any load that needs three legs from a three phase system can not be considered single phase. Single phase from a three phase system only needs a connection to two legs.
Question is incorrect. in a 240 Volt single phase circuit, how can you have A phase and B phase?
Work it out for yourself. The equation is: Z = E/I, where Z is the impedance, E is the supply voltage, and I is the load current.
The difference between a single and a three phase online UPS is a 3 phase can supply a 100% unbalanced load on its output without affecting its performance. A single phase cannot supply a 100% unbalanced load on the output without affecting its performance.