120 /208 any phase will give 120 to neutral
its better to pick different phases for all the 120v loads
if a b and c are all balanced there is no current in the neutral
the neutral is usually undersize because its not expected that all the single phase loads will be on one phase
panel breaker numbers ... Phases
1 - 2 a
3 - 4 b
5 - 6 c
7 - 8 a
9 - 10 b
11-12 c
1 3 5 is identical to 2-4-11
it would be very hard to randomly get all the single phase loads on one phase putting random combinations of 1 2 and 3 pole breakers in a panel but you dont need to gamble
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.
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 term, single-phase 'panel', describes an electricity distribution panel (called a 'consumer unit' in the UK) comprising line, neutral, and earth (ground) busbars, supplying a number of circuits which are each protected with either a fuse or a miniature circuit breaker. The panel normally incorporates an isolation switch that will disconnect the busbars from the supply system. The panel is fed from the utility company's supply system, via a fuse and energy meter.
Multiple circuits can typically share one neutral as long as the currents do not exceed the capacity of the neutral wire. This practice is common in residential electrical installations, especially in split-phase systems where two circuits share a neutral. It is important to follow local electrical codes and regulations when combining circuits on a shared neutral.
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.
If there is no neutral available you cannot, unless you use an autotransformer and derive a neutral. A panel with no neutral is called a power panel and is used to supply 240 single and three phase loads.
Not usually, if the three phase pump is a three wire pump then the disconnect does not need a neutral. The pump control may or may not need a neutral depending on the voltage system that the control panel needs.
Neutral is grounded in a distribution panel. At best, it is only a few tens of millivolts away from ground and it certainly would not be DC - it would be AC.
A delta-connected system is described as being a three-phase, three-wire, system, and doesn't have a neutral. But a balanced star (wye) connected load (e.g. a three-phase induction motor) doesn't actually require a neutral.
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.
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.
Easy as one,two and three. There are four primary wires coming from you service panel.(provided you have three phase service) you can check by looking at the weather head on the roof. if it has three wires you have single phase but if it has four then you have three phase. the hot wires will be black,red and brown. the neutral will be white or green. the welder should have a manual that will give you the lead phase wire(most likely black to black) the other two hot wires can hook to any other hot wire. The neutral goes to the white or green and posts to the panel. If the welder has a switching power supply then you must have a three phase converter.
The term, single-phase 'panel', describes an electricity distribution panel (called a 'consumer unit' in the UK) comprising line, neutral, and earth (ground) busbars, supplying a number of circuits which are each protected with either a fuse or a miniature circuit breaker. The panel normally incorporates an isolation switch that will disconnect the busbars from the supply system. The panel is fed from the utility company's supply system, via a fuse and energy meter.
there isnt a high leg in a three phase 480v panel only on 240v panels
Multiple circuits can typically share one neutral as long as the currents do not exceed the capacity of the neutral wire. This practice is common in residential electrical installations, especially in split-phase systems where two circuits share a neutral. It is important to follow local electrical codes and regulations when combining circuits on a shared neutral.
A three phase system will have 3 phase branch circuits and no neutral.
As far as I understand, you don't need neutral line for connecting appliances that is 3-phase compilant. You only need the neutral line to connect a single phase appliance, which you connect along with one of the three lines.