Problems and Efficiency of Electrical Grounding System in 7 Community Hospitals Under-60-beds in Chiang Rai Province - สภาพปัญหาและประสิทธิภาพของระบบสายดินที่ใช้กับ ระบบไฟฟ้าในโรงพยาบาลชุมชนขนาดไม่เกิน 60 เตียง พื้นทีจังหวัดเชียงราย

Abstract

    The Health Service Support Department of Ministry of Public Health reported the outcomes of it surveys that there was a high risk of electrical hazards from improper grounding system in public hospitals. Some patients and hospital staff had encountered electric shock while using medical devices; and a fatal cases was reported. Although all hospitals were equipped with grounding devices during the construction, deterioration of the grounding system might happen as a result from frequent incidents of
flooding. Thus, the author decided to assess the problems and the efficiency of the ground system the linked with medical devices in hospitals. Seven under-60-bed community hospitals in Chiang Rai province were purposively selected. The main objectives were to study the electrical grounding system
with particular attention on the models, capacity, installation methods, and associated problems and constraints; and to measure the electrical resistance at some ground rods at risk of electrical hazard to people (inpatient wards, surgery rooms, intensive care units, etc.). It was found that there were 262 ground rods in the 7 hospitals. Only 142 potentially risky rods (54.20%) were examined. Models and installation of the majority of the ground rods (141 or 99.30%) were not in line with the standard. There were also problems with improper connections between electrical wire and the ground rods at all sites, non-standardized length of ground wire (as only 23 sites or 16.20% had utilized 2.4 standard length); and wire size smaller than 2.5 square millimeter (all sites) – compared to 10.0 mm2 standard. The electrical resistance at all sites was higher than the standard value of 5 ohm. In conclusion, the electrical grounding system in all 7 district hospitals was not in line with the standard. Measures to standardize the grounding system and educate hospital staff on this issue are urgently needed.
Key words: ground wire, ground rods, electrical resistance