Have a qualified electrician inspect the box annually. Professionals can: • Test Electrical Parameters: Measure voltage, current, and insulation resistance. • Check Code Compliance: Ensure safety standards are met. This section contains information on inspecting and performing preventive maintenance on HVL/cc Metal-Enclosed Switchgear. Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. See NFPA 70E, NOM-029-STPS-2011, or CSA Z462. This equipment must only be. Low-voltage intrusive switchboards regulate and distribute power in buildings and facilities. Once the source of the problem is identified, a clamp meter can help you. Comprehensive maintenance is crucial for ensuring the safe and stable operation of high-voltage power distribution systems. Look for any signs of burnt or damaged wiring.