Reliability Assessment and Protection Coordination of Low-Voltage Electrical Distribution Systems in Nigerian Manufacturing Facilities

Abstract

Reliable electrical infrastructure is indispensable to industrial productivity, operational safety, and sustainable manufacturing in Nigeria. This review examines the design and performance of low-voltage distribution networks, with particular emphasis on reliability assessment, electrical fault behaviour, protective-device coordination, and power quality. It aims to identify major sources of operational vulnerability and establish practical priorities for improving continuity of supply within manufacturing facilities.
A structured narrative synthesis of published engineering literature and applicable technical standards, restricted to sources published through 2020, was undertaken. The discussion integrates distribution architectures, interruption and availability indicators, component failure analysis, probabilistic assessment methods, short-circuit studies, and protection selectivity principles. Particular consideration is given to facilities combining utility supply with standby generation and renewable energy resources.
The synthesis identifies several recurrent reliability concerns: ageing or inadequately maintained equipment, overloaded feeders, insulation deterioration, voltage disturbances, and protection arrangements that may disconnect healthy production circuits during localised faults. It further shows that alternative electricity sources can modify available fault currents, making coordination assessments under distinct operating configurations essential. Reliability indicators and condition monitoring provide complementary means of prioritising interventions, although limited facility-specific failure data constrain the strength of conclusions about Nigerian manufacturing performance.
The review recommends periodic electrical audits, updated short-circuit and discrimination studies, risk-based preventive maintenance, power quality monitoring, and selective investment in redundancy and critical-load support. Consistent fault reporting, workforce development, and field-based validation are also necessary. Ultimately, more dependable industrial distribution requires integrating sound network design with verified protection settings and evidence-led maintenance decisions, rather than relying solely on additional generation capacity across diverse Nigerian industrial settings.