Neutral shift in a three phase system can occur when service Transformers on long distribution lines are connected to provide four wire star service (like 277/480V) and the common primary connection (like three 14.4 kV transformers on a 24 kV line) on the transformers is left ungrounded. Observed Neutral shift can be so severe, depending on the situation, that in the example given here 480 Volts phase to phase and 470 Volts phase to Neutral were measured. This condition is only present while the load (this was a 100 HP pump) is not in service.
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.
Only one neutral conductor is typically in a 3 phase panel.
If the heater is rated as a 3 phase 480 volt heater then a neutral is not needed. If the voltage stated is 277 volts three phase then a neutral is needed.
3 phase /sqrt(3) * 30 degree phase shift = single phase.
415V 3 phase is the line to line voltage. The line to neutral of this supply is 230V single phase. Therefore you use one of the phases and the neutral.
On a Delta 3-phase you connect the single phase loads between pairs of the 3-phases. Warning both sides of these loads will be hot! You may want to use 3 isolation transformers so that the real loads have a neutral line.On Y 3-phase you connect the single phase loads between one of the 3-phases and neutral.In each case to balance the loads, try to put similar loads on each phase (or pair of phases).
A three phase system will have 3 phase branch circuits and no neutral.
Only one neutral conductor is typically in a 3 phase panel.
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.
If the heater is rated as a 3 phase 480 volt heater then a neutral is not needed. If the voltage stated is 277 volts three phase then a neutral is needed.
3 phase /sqrt(3) * 30 degree phase shift = single phase.
415V 3 phase is the line to line voltage. The line to neutral of this supply is 230V single phase. Therefore you use one of the phases and the neutral.
The formula to use is, phase voltage /1.73 = phase to neutral (ground) voltage.CommentThere is no such thing as a 'phase to phase', or 'phase to neutral' voltage. The correct terms are 'line to line' and 'line to neutral'. So the above answer should read: line voltage/1.73= line to neutral voltage = phase voltage.
yes
All three phase four wire systems have the ability to produce a voltage to ground or neutral. Take any phase voltage be it primary or secondary and divide it by the sq. root of 3 which equals (1.73) and you will obtain the phase to ground or neutral voltage. The ground and neutral should be of the same potential and when talking about electrical installations these two words get interchanged quite often. Some three phase secondary voltages are 208, 480 and 600 volts. Electricians will talk about voltages of 120/208, 277/480 and 347/600. The first number is the phase to neutral voltage and the second number is the phase to phase voltage.
A three phase delta system does not use a neutral in its operation.
You can divide a three phase service into (3) single phase circuits providing you have a 4th neutral wire.