Load unbalance in a 4-wire, 3-phase power distribution network is a common nuisance. This causes wasteful energy in the form of large current in theNeutral wire which is normally rated at lower current capacity. Prolonged high current condition in Neutral wire eventually leads to unpredictableneutral failure, causing severe fire hazards and complete disruption of the voltage distribution among different phases leading to damage in equipments connected to lowest loaded phase. Moreover, an unbalanceddistribution network causes zero-sequence magnetic flux leakage in the sub-station transformer and becomes a source of electro-magnetic-interference (EMI) which impairs the functioning of sensitive electronic instruments. At the same time, triplens (the 3rd harmonic and higher) of the zero-sequence current enter the Ground from the Neutral at the sub-station transformer and interrupts communication using the Ground. Large harmonics content in the supply due to extensive use of non-linear loads (like SMPS, switched SCR) also causes hike in Neutral current. In this work a sensor head based on simple technique has been described which can monitor minute load unbalance, harmonics and voltage spikes in the power distribution network and has the ability toswitch off a DB (when parameters exceed safe limit) prior to a massive neutral failure.