The TUE-150 Residential Wiring Trainer is used to demonstrate residential, electrical principles to HVAC/R students. Also, it has provisions for extensive switching and connection of lamps and outlets. The 24 volt power supply is used to wire and test all circuits. After the instructor has approved wiring, 120 VAC can be applied using the key-lock circuit breaker control. The ability to use low voltage for testing and 120 VAC for final wiring is a valuable teaching aid. Since all initial breadboarding and testing can be done at low voltage, the 120 VAC is only made available after the instructor has used the key to turn on the Electro-Lock to apply 120 VAC. With the inclusion of the dual 24 VAC power supply, this trainer is very useful for introductory classes on electrical wiring in residential settings. Teachers are able to provide hands-on learning with this type of training unit. Included with this model is an educational manual where students learn proper electrical hookups and wiring.