Heavy duty lamp holders are required on branch circuits having a rating in excess of?

Heavy duty lamp holders are specifically designed to accommodate the increased mechanical and electrical demands that arise in circuits with higher amperage ratings. In Rhode Island and many other jurisdictions, regulations often stipulate that heavy duty lamp holders must be used for branch circuits rated in excess of 20A to ensure safety, reliability, and reduce the risk of overheating or failure.

When circuits exceed this rating, the electrical components face greater stress, which can lead to potential hazards if standard lamp holders are used, as they may not handle the increased electrical load effectively. Therefore, adhering to the requirement for heavy duty holders on circuits over 20A is essential for maintaining safe electrical system operations. Other options represent lower amperage thresholds, which are typically manageable with standard lamp holders, thus reinforcing the necessity of heavy duty versions at the 20A mark to accommodate more demanding applications.