neutral will carry current only during unbalanced or faulty
condition.During balanced condition current through neutral
is zero(Ia+Ib+Ic=0).Magnitude of neutral current depends on
the fault current magnitude.
In case of SIngle Phase System Neutral will carry current
of same magnituge as phase current.
In case of 3 Phase, Star Connected System, neutral will
carry current only during unbalanced or Phase to Neutral
fault condition. During balanced condition current through
neutral is zero(Ia+Ib+Ic=0). In case of Unbalance load
Neutral Current can be maximum as phase current. & In case
of Phase to Neutral Fault Magnitude of neutral current will
be same as fault current. In case of Phase to Earth Fault,
neutral current will be 0. Earth current is suppose to pass
through Earthing grid or Armoure of cable.
Nuetral will carry current in unbalance & faulty / EF or SC
condition. During normal condition vector sum is Zero and
megnitude is also zero, but in faulty condition zero
sequence current will flow through neutral and megnitude
depends upon fault strenght.
As per KCL Sum Of Individual Current is Equal to Zero.
That's the Neutral Point is Zero.
In Unbalnce Condition the current will flow in neutral
point. that magnitude will Based on Faulty Current.
Balanced Condition Ia+Ib+Ic=0(N)
Unbalanced Condition Ib+Ic=-Ia(N)Faulty System only.
In normal condition there will not be any current in
Neutral, and the vector sum will be 0, If there is any
EF/SC/Unbalance occured the fault current will always pass
through the lowest resistance path in this case neutral is
the lowest resistance path so when neutral will caryy the
load the magnitude will be equal to the magnitude of fault
An 11kv system consisting of an underground cable to a sub
station about 300 meters away was shut down for about 10
hrs. On energising, it tripped off on earth fault about
10---20 mins later 6 times but since than it is not
tripping.its already 3 weeks now. The SPAJ was found to be
fine. what could be the cause.No test had been done to
determine the cause of the trippings till now because of