ELECTRICAL SERVICE DESIGN OF AN OFFICE BLOCK WITH PV SYSTEM INCORPORATED

ABSTRACT

This work aims to design an electrical service for an office block with PV system incorporated, taking the departmental office floor of Electrical/Electronic Engineering, University of Benin as a case study. Electrical service design with PV system was carried out for the office floor, based on a draft architectural plan drawn using AutoCAD software. Offices were grouped into three- small offices, large offices and very large offices. The design includes (lighting design and socket design). Lumen method was used for the lighting design using Spectral MIREFA and Philips RC540B luminaires. Dialux Evo 9.2 was also used for the lighting design for comparative analysis with result from lumen method. Dialux software operates using Illuminating and Engineering Society of North America (IESNA) standards. The 13A sockets were designed in ring circuits, while 15A sockets for air conditioners were in radial circuits. Generator sizing and PV system design was developed based on load audit and priority load allocation. Cables sizing was carried out using IEE regulation (2008). Comparative analysis was carried out by simulating Lumen method on the Dialux software and photometric parameters (illumination, uniformity of illumination and Unified Glare Rating (UGR)) were analyzed. Results from the analysis showed that the Lumen Method achieved a better perpendicular illuminance of 360lx, 348lx and 316lx for the small offices, large offices and very large offices respectively against the target value of 300lx, than Dialux calculations which gave a perpendicular illuminance of 214, 248 and 241 for the same target value. Also, the lumen method achieved better uniformity of illumination, having values of 0.034, 0.016 and 0.030 against 0.074, 0.002 and 0.024 gotten from Dialux design for the small, large and very large offices respectively, though both results were not up to the standard value recommended by IESNA as 0.4. The UGR results for lumen method had points with stronger glare exceeding the standard of 19 set by IESNA, while Dialux had lower glare, making it the better design in terms of glare rating. Overall comparism shows that the lumen method is better suited for lighting design calculations using Spectral MIREFA and Philips RC540B luminaires, while Dialux is suitable for lighting simulation and presentation.