Electrical testing and inspections should be performed regularly to maintain safety, reduce downtime, and support system reliability. Most facilities complete electrical testing and infrared inspections annually, while critical equipment such as medium-voltage gear, switchgear, and production systems may require more frequent testing depending on load, age, and operating conditions.

According to NFPA 70B, all electrical equipment should be inspected at least every 12 months. Testing intervals vary based on equipment condition: Condition 1 (like new) every 60 months, Condition 2 (minor issues) every 36 months, and Condition 3 (significant issues) every 12 months or sooner. Infrared thermography is recommended annually for all equipment.

Guidelines from InterNational Electrical Testing Association (NETA) recommend visual inspections every 12 months, with full testing typically every 24–36 months. This applies to equipment such as switchgear, switchboards, transformers, cables, and circuit breakers, with intervals adjusted based on equipment age, criticality, and operating conditions.

Occupational Safety and Health Administration (OSHA) does not define specific maintenance intervals but requires facilities to follow recognized standards and manufacturer recommendations to maintain a safe working environment.

As a general industry best practice, preventive maintenance is typically performed every 1–3 years, depending on the environment and system demands. Harsh conditions such as dust, moisture, or chemical exposure, along with critical operations, may require more frequent inspections. Maintenance activities often include visual inspections, infrared scans, electrical testing (such as insulation resistance and contact resistance), as well as cleaning and tightening of connections.