Final answer:
Non-linear load isolation transformers are specified when high levels of harmonics are present.
Step-by-step explanation:
Non-linear load isolation transformers are specified when high levels of harmonics are present. Harmonics are electrical frequencies that are integer multiples of the fundamental frequency.
Non-linear loads, such as computers, variable speed motors, and fluorescent lights, generate harmonics that can cause disturbances in the power system. Isolation transformers can help mitigate these harmonics and provide a clean and stable power supply to sensitive equipment.