Which of the following is NOT a component of a hydraulic system in equipment?

A hydraulic system is designed to transmit power through fluid, making it essential for various equipment, such as construction machinery. The components essential for a hydraulic system include lines and hoses, which transport the hydraulic fluid, a fluid reservoir to hold the hydraulic fluid, and a relief valve to manage excess pressure within the system.

The correct choice highlights the fact that an electrical system is not part of a hydraulic system. While hydraulic systems may be used alongside electrical systems in modern machinery, the electrical components do not contribute to the hydraulic aspects of power transmission. Therefore, understanding the distinction between hydraulic components and those that are electrical is crucial in the context of machine operation and maintenance.