Analysis of Failure Patterns and Downtime Costs in Diesel Generator Sets at a Telecommunications Base Station Network in Abuja

Telecommunications base stations across Nigeria depend almost entirely on diesel generator sets for operational power supply due to unreliable grid electricity, making generator reliability a critical factor in network uptime and operational expenditure management. This study analyses failure patterns, maintenance costs, and downtime impacts in the diesel generator fleet supporting a telecommunications base station network in the Federal Capital Territory. Maintenance records for 80 generator sets with individual operational histories of three to seven years were reviewed and coded by failure mode, affected system, and downtime duration. Failure mode and effects analysis was applied to the leading failure categories, and Pareto analysis was used to identify the vital few failure types responsible for the majority of total downtime. Repair and fuel costs associated with unplanned maintenance events were extracted from financial records and compared against preventive maintenance expenditures. Results showed that fuel system faults, battery failures, and cooling system failures collectively accounted for 74 percent of all recorded failure events and 68 percent of total generator downtime. Mean time between failures averaged 420 hours, below the manufacturer-recommended threshold. Predictive cost analysis demonstrated that transitioning to condition-based maintenance could reduce unplanned maintenance costs by an estimated 31 percent. The study presents a priority-based maintenance optimisation plan tailored to the telecommunications off-grid power context. Keywords: diesel generator, failure analysis, telecommunications, maintenance cost, Abuja.