This might help you. First and foremost is the information the manufacturer puts on the nameplate of the motor. Second, the generic amperage can be found on motor charts that are on the internet. Third you can use a formula to find the approximate amperage. HP = Amps x Volts x 1.73 x pf/746. Transposed for Amperage, Amps = HP x 746/Volts x 1.73 x pf. Use power factor = .9 For estimating a 10 HP motor running on 208 volts. Amps = 10 x 746/ 208 x 1.73 x .9 = 7460/323.85 = 23.03 amps. See how much easier it is to read the nameplate.
The phase voltages (i.e. line-to-neutral in a 4-wire system, or line-to-line in a 3-wire system) of a three-phase system are displaced from each other by 120 electrical degrees. Each phase voltage, in fact, is rarely in phase with its phase current, as the phase-angle (the angle by which a phase current lags or leads its phase voltage) is determined by the load not by the supply.In general, most loads are resistive-inductive so the phase current usually lags the phase current.So, to answer your question, it's not important that a phase current is in phase with its phase voltage -if that is what you are asking.
To calculate the current on a delta to star transformer, first identify the line current in the delta configuration (I_line). The phase current in the star (wye) configuration (I_phase) can be calculated using the formula: I_phase = I_line / √3. This relationship arises because the line current in a delta system is √3 times the phase current in a star system. Therefore, knowing the line current allows you to easily find the phase current in the star configuration.
Phase resistance refers to the resistance encountered by current in a single phase of a multi-phase system, such as a three-phase electrical system. It is not directly determined by the voltage level, like 500 volts, but rather depends on the characteristics of the load and the conductors in the circuit. To determine the phase resistance, one would typically need to know the current flowing through the phase and the power factor of the load. If you have specific details about the load or system, I can help calculate or explain it further.
In a three-phase generator, the currents in the three phases are 120 degrees out of phase with each other. This phase displacement means that when one phase current is at its peak positive value, the other two are at lower values, thereby balancing the overall current. As a result, the sum of the currents in a balanced system is zero at any instant, which minimizes the overall neutral current and reduces losses in the system. This cancellation allows for efficient power distribution and minimizes the need for additional neutral conductors.
If all three legs of the system are balanced then zero amps will flow all the way up to 100 amps if only one leg of the three phase system is used. The neutral in a wye three phase system carries only the unbalanced current. This is why in services for a three phase four wire system you are allowed to reduce the size of the neutral conductor.
All current is the passage of electric charges from one terminal to another through a conductor so there is no real difference in the type of current that flows in a 3 phase system compared to a single phase system.
The current carried by the neutral of a three phase four wire system is the un balanced current. If the three phase system was completely balanced on all three phases there would be no need for a neutral, eg a three phase motor. This neutral current will be less that the phase current so a reduction in the neutral size is allowed.
The limit or range of the neutral current in an unbalanced three phase system is the third harmonic in single phase non-linear load current is the major contributor to neutral current.
Over all losses are less in three phase AC system compared to 1 phase. For a given load (KW) 1 phase system would draw more current
Add them upAnswerThere is no 'total' current in a three-phase system. The current flowing in each line (not 'phase') is considered separately. And you most definitely don't 'add them up'!
A load current is a current drawn by an electrical load. In other words, it is the current flowing from the source to the load.For a single-phase system, a line current is a current flowing through the line, or 'hot', conductor, while the current through the neutral conductor is called the neutral current.For a three-phase system, the three 'hot' conductors between the load and the source are called 'lines' and, so, the currents passing through them are called 'line currents'. For a three-phase system, loads are either connected between line conductors (delta-connected system) or between each line and the neutral (star- or wye-connected system), and represent the phases -so the currents passing through the loads are called 'phase currents'.For a balanced three-phase system, the line current is 1.732 times the value of a phase current, where the phases (loads) are connected in delta. For phases (loads) connected in star (or 'wye') the line current is numerically-equal to the phase currents.
The phase voltages (i.e. line-to-neutral in a 4-wire system, or line-to-line in a 3-wire system) of a three-phase system are displaced from each other by 120 electrical degrees. Each phase voltage, in fact, is rarely in phase with its phase current, as the phase-angle (the angle by which a phase current lags or leads its phase voltage) is determined by the load not by the supply.In general, most loads are resistive-inductive so the phase current usually lags the phase current.So, to answer your question, it's not important that a phase current is in phase with its phase voltage -if that is what you are asking.
In a balanced three-phase system, the current in the neutral wire should ideally be minimal as the three phase conductors carry equal and opposite currents that cancel out in the neutral wire. However, if the loads are unbalanced, the neutral wire may have higher current due to the uneven distribution of power among the phases. This can happen when loads on each phase are different or when single-phase loads are connected between a phase and neutral, leading to increased neutral current.
In a Wye/star system the overloads look at the phase to neutral/ground current; not phase to phase current. Which is always calculated as root three or 1.73205.............etc. Therefore the overloads have to be set to the phase to neutral/ground current.
A phase current is the current passing through a phase, whereas a line current is the current flowing through a line.
A smaller neutral wire in a three phase system can be used because it does not carry the full line current. It carries the unbalanced current of all three leg loads. This is one reason that three phase loads on a distribution panel should be equalized as much as possible to reduce the current on the neutral.
House current is single phase.AnswerIt depends on the system supplying your residence. Most are single phase, but some, such as here in Cyprus, have a three-phase supply as standard.