Current rating is not necessary in case of-

Current Rating in Electrical Components:

• Electrical components are rated based on their ability to handle specific amounts of current, voltage, and other factors. The current rating is crucial for components that carry and interrupt current, such as circuit breakers and load break switches.

Isolators:

• An isolator is a mechanical switch that isolates a part of the circuit from the system as needed.
• The primary function of isolators is to ensure that a section of a circuit is completely de-energized for service or maintenance.
• Isolators are usually operated under no-load conditions, meaning they do not carry current when they are opened or closed.
• Since isolators are not intended to break load current, the current rating is not critical for their operation.

Circuit Breakers and Load Break Switches:

• Circuit Breakers: These are designed to protect an electrical circuit from damage caused by overload or short circuit. They can interrupt current flow in the event of a fault and therefore must be rated for the current they are expected to interrupt.
• Load Break Switches: These switches are designed to open and close circuits under load conditions. They must handle the current flowing through the circuit when switching operations are performed, making their current rating critical.

From the above explanations, we can conclude that:

• Isolators do not require a current rating because they are not used to interrupt the current flow under load conditions.
• Circuit breakers and load break switches require appropriate current ratings to ensure safe and reliable operation under load conditions.