Is it true that a 120/240 volt, single-phase, 3-wire system with a grounded neutral is the most popular system for residential services?

A 120/240 volt, single-phase, 3-wire system with a grounded neutral is indeed the most popular choice for residential services in the United States. This configuration effectively provides the standard voltage for household appliances, powering both 120-volt and 240-volt devices. The grounded neutral is particularly important for safety, as it helps prevent electrical shock and reduces the risk of electrical fires by providing a path for fault currents.

While there are other systems used in different applications or in specific regions, the prevalence of this specific system stems from its balance of efficiency, compatibility with common household appliances, and safety standards. As a result, saying it is the most popular system accurately reflects its widespread acceptance and use across many residential settings.