Which aspect is generally not mandatory in the evaluation of electrical equipment?

In the context of evaluating electrical equipment, compliance with international standards is indeed a significant consideration, but it's not universally mandatory for all types of electrical equipment. Standards such as those set by the International Electrotechnical Commission (IEC) or the Institute of Electrical and Electronics Engineers (IEEE) provide guidelines that enhance safety and performance. However, certain equipment may not be subject to these international standards depending on local regulations or specific applications.

On the other hand, conformity with NFPA 70, which is the National Electrical Code (NEC), is legally required in many jurisdictions as it governs safe installation practices. Electrical insulation is crucial for the safety and functionality of electrical devices, preventing short circuits and protecting users from electric shock. Safeguarding of persons is fundamentally essential as it focuses on ensuring user safety, which is a primary concern across all electrical equipment evaluations. Thus, while international standards play a valuable role, they are not always mandatory, making this option the most appropriate answer.