Florida Home Inspector Practice Test

What kind of electrical service is indicated by three wires on a masthead, one tied back?

1. 240 Volt Service

2. 120 Volt Service

3. 480 Volt Service

4. 60 Volt Service

The correct answer is: 120 Volt Service

The correct answer pertains to the configuration of the electrical service indicated by three wires on a masthead, with one tied back. In residential applications, a common feature of 120 Volt service is having a total of three wires, which typically includes one hot wire, one neutral wire, and a ground wire or a second hot wire for a 240 Volt connection. When one wire is tied back, this often signifies that the setup is standard for 120 Volt service, utilizing the hot and neutral wires while potentially indicating that the third wire (which could be tied back) is either a ground or a secondary line that isn't actively used in that particular instance. In contrast, 240 Volt service generally involves two hot wires and no neutral, making it less likely that one of the wires would be tied back in a way that suggests it is unused. The availability of 480 Volt service, on the other hand, typically would involve a more complex system with more than three wires due to the higher voltage and power needs, therefore it also wouldn't suit this description. Lastly, 60 Volt service is not standard in residential wiring, which makes it an unlikely candidate for this type of masthead configuration. The specifics of a residential setup align closely with the characteristics described for