Field survey of electrical grounding systems on commercial broiler houses in Mississippi and Alabama

Authors: Rowland, Matthew; CHESSER, G - Mississippi State University; LINHOSS, J - Auburn University; DAVIS, J - Auburn University; CAMPBELL, J - Auburn University; Purswell, Joseph - Jody

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/13/2023
Publication Date: 4/15/2023
Citation: Rowland, M.R., Chesser, G.D., Linhoss, J.E., Davis, J.D., Campbell, J.C., Purswell, J.L. 2023. Field survey of electrical grounding systems on commercial broiler houses in Mississippi and Alabama. Applied Engineering in Agriculture. 39(2):245-249. https://doi.org/10.13031/aea.15501.
DOI: https://doi.org/10.13031/aea.15501

Interpretive Summary: Construction, maintenance, insurance, and operations cost have continued to increase in commercial broiler houses as more advanced housing control systems are adopted. While broiler house control systems have relied upon electronics for the last 20 years, the advent of isolated on-farm control networks may increase the risk of damage from lightning strikes or other electrical surges. Proper earth grounding is essential to protect control systems and critical house management equipment such as fans, heaters, lighting, feeders, etc. A field survey of electrical grounding systems was performed on commercial broiler houses in Mississippi and Alabama and included earth ground resistance, house age, grounding system type. A majority of surveyed broiler houses were at or below the building code recommendation of 25 ohms. Traditional ground rod systems had fewer (58%) houses within code recommendations as compared to the Ufer ground system (74%). The data illustrate the necessity of regular inspections of broiler house electrical systems to ensure safe and reliable operation, especially in areas prone to overvoltage or lightning-induced damage.

Technical Abstract: Commercial broiler house construction, maintenance, and insurance costs continue to increase with the adoption of advanced housing control equipment that aid in flock management through automation of environmental control and data collection. Proper earth grounding is essential to protect these systems from lightning strikes or other dangerous electrical surges. However, the quality of grounding systems on broiler farms in Mississippi (MS) and Alabama (AL) was unknown. Therefore, a field survey of electrical grounding systems was performed on 96 commercial broiler houses of varying ages in MS and AL. Survey parameters included earth ground resistance (', ohms), house age, grounding system type (Ufer or traditional grounding rod), and any electrical system/controller updates. 64% of surveyed broiler houses were at or below the NFPA recommendation of 25-'. 58% of traditionally grounded houses and 74% of Ufer grounded houses were at or below the 25-' ground resistance threshold, respectively. Ufer grounding has become a required or preferred method over traditional ground rods in new broiler house construction to improve earth grounding. Producers should have their grounding systems inspected annually with an earth ground resistance meter to mitigate both overvoltage and lightning-induced damage.