After completing a limited-energy cabling installation, which testing is typically performed?

• A. Continuity check and insulation resistance only.
• B. Continuity check, insulation resistance, polarity check, and functional testing of devices.
• C. Polarity check and functional testing only.
• D. Insulation resistance and polarity check only.

Answer: (B)

After a limited-energy cabling installation, you want to verify both the wiring path and how the system will behave in operation. The standard set of tests includes a continuity check to confirm there is a complete path from source to load, an insulation resistance test to ensure the insulation is sound and there’s no leakage that could cause shocks or faults, a polarity check to verify the conductors are connected with the correct orientation so devices receive the proper supply, and functional testing of the connected devices to confirm they operate as intended under normal conditions.

Together, these tests cover both safety and performance: continuity shows the circuit is physically intact, insulation resistance guards against leakage and arcing, polarity prevents misoperation or damage due to reversed connections, and functional testing verifies that devices respond correctly when powered and controlled. Choosing to perform only some of these tests could miss a problem with insulation, incorrect wiring polarity, or a device that doesn’t operate correctly, leaving risks or operational issues unresolved.