ABSTRACT
Poor electrical services design can result to risk of fire outbreak due to use of inappropriate cables and size, wastage of electrical materials, poor load balancing and wrong choice of components. Unreliable power supply in Nigeria has posed a lot of challenges in our industrial and domestic usage. This project is designed to address these challenges by carrying out the design of a hybrid Electrical services for an administrative Building, Blocks of laboratory and lecture theater.
Extensive calculations for lighting points, power points, cable sizing, bus bar selection, transformer size and the entire load requirement of the building under consideration, also to integrate other reliable and alternative sources of power while using a transfer capability device to regulate the switching between these sources.
A survey of the architectural drawing was carried out by considering the dimensions of each office, convenience, corridor, laboratories, Lecture Theater on each of the floors of the building.
Designs was carried out to determine the number of lighting points required using lumen method by considering the dimensions of each office, power points, AC points, fire alarm system, lighting protection system that each aspect of the building will require. Transformer, Generator and Automatic Changeover switch designs were also done. Cables were approximately sized using rated standards. Load balancing was carried out to ensure each phase is not over loaded. A PV system was designed to serve as an alternative and emergency backup supply.
The result shows that For Open office A on the Ground Floor with an area of 108m2 (15m x 7.2m), 10 lighting points (LED, 6W), 4 power points (300W per 13Amps), 8 fans (56”, 60W), 4 ACs (8 HP) will suffice. This was replicated for all aspects of the building. For the wiring arrangement, Bus Bar Trunking system was adopted over Conventional wiring method due to ease of installation, safety, ease of maintenance and future expansion purpose. A transformer rating of 800KVA, 11/0.415KV was selected after the total load of the entire building was determined. Two generators of 500KVA each were also adopted considering the load demand calculated. One of the generators is to act as backup to the other. The Inverter choice of 10KVA was selected for the Administrative Building while a 5KVA Inverter was selected for the Block of Laboratories and Lecture Theaters. These choices were made after the load demand to be supplied by the Inverters was determined. Appropriate smoke detectors, fire alarm system and lightning protection system were also chosen after design calculations were done. The Automatic Transfer Switch selected is majorly to monitor and switch between available powers sources considered. The Bill of Engineering Measurement and Evaluation was estimated to be Four Hundred and Thirty Two Million, Seven Hundred and Ninety Nine Thousand, One Hundred Naira Only (N432,799,100.00).. This amount would be required to complete the project. The Entire electrical connection has been designed based on IEC and NEC Standard and Code respectively. NEC code standard was adopted due to the nature of the building (High rise building) and also, it places more emphasis on electrical fire safety of under the National Fire Protection Agency (NFPA).
