Loss of neutral in star connected system
Loss of neutral in star connected system
(OP)
Gentlemen (and ladies),
I would be grateful if you could help me to ascertain the phase to phase voltages which will result within a three phase star connected network should the neutral conductor become disconnected from the star point of the transformer. This occurred in a hospital recently and damage resulted (Light fittings burnt out etc). Obviously the load on each phase will determine the voltage but are there any other factors that need to be considered ?
I would be grateful if you could help me to ascertain the phase to phase voltages which will result within a three phase star connected network should the neutral conductor become disconnected from the star point of the transformer. This occurred in a hospital recently and damage resulted (Light fittings burnt out etc). Obviously the load on each phase will determine the voltage but are there any other factors that need to be considered ?






RE: Loss of neutral in star connected system
The voltage developed across a load can be anything between close to zero volts to sqrt(3)*phase-neutral voltage.
Theoretically, there can be resonance phenomena if you have highly inductive loads connected from one phase to neutral and highly capacitive loads from another phase to neutral. Loss of neutral will then put L and C in series and you may have a resonance amplification that drives the voltage well above phase-phase voltage. But such a situation is not very likely to occur outside the school-books.