Journeyman Electrician Practice Exam

Surge-protective devices (SPDs) should not be installed on circuits exceeding what voltage?

1. 600 volts

2. 1,000 volts

3. 1,200 volts

4. 1,500 volts

The correct answer is: 1,000 volts

Surge-protective devices (SPDs) are designed to protect electrical equipment by limiting voltage transients caused by surges such as lightning or switching operations. The correct voltage limit for the installation of SPDs is 1,000 volts, as SPDs are typically rated for systems operating at or below this voltage level for optimal performance and safety. Exceeding this voltage can pose risks because SPDs are not designed to handle higher voltages effectively, which may lead to product failure, damaged equipment, or even electrical hazards. Systems operating above 1,000 volts usually require specialized protective devices designed for higher voltage applications, hence the importance of adhering to this upper limit when installing SPDs in standard environments. This adherence ensures the protective devices function correctly and provide the intended protection against surge events. Understanding the design and application of SPDs in relation to voltage limitations is crucial for ensuring not only the equipment's longevity but also the safety of the overall electrical system.