Loose bolts, current transformer mounting, doors, covers and similar parts can resonate with the normal 60-cycle hum and cause excessive noise/humming. Some operational noise and/or humming in electrical equipment can be expected. However, in actual applications, distribution boxes often encounter a series of problems, which not. Outdoor low-voltage power distribution boxes (hereinafter referred to as "distribution boxes") are low-voltage distribution equipment used in 380/220V power supply systems to receive and distribute electrical energy. When they start tripping, overheating, or making strange noises, it's more than just an inconvenience - it's your home's cry for help. Here are the main risks linked to harmonics: Disturbance in communication networks and telephone lines.