Difference Between Insulator and Isolator (With Table)

Insulators and isolators are something that we used every day without knowing. The purpose of both insulator and isolator is the same, which is to prevent any risk from happening from electric current or heat. One limits the amount of energy while the other becomes a wall to prevent the passing of energy. Though insulators and isolators serve a kind of similar purposes, they differ in some basic aspects.

Insulator v/s Isolator

The main difference between Insulator and an Isolator is that an insulator is a kind of material that supplies electrical isolation by itself between the part that has current and the part which doesn’t have current. Isolators, on the other hand, are devices with the mechanism of connecting and disconnecting to cut off a certain part of an electric circuit.

An insulator is any material or substance that prevents the transfer of energy such as heat, electricity, or cold. An insulator has low conductivity due to which the flow of energy is negligible. Although insulators have poor conductivity, they can better be described as a material with high resistance to the heart or any kind of every.

An isolator is a mechanical switch that is operated manually for cutting off the faulty part of the substation. Isolators are used to separate the defective part from the working section to prevent any severe faults that can happen in the future. Disconnector or disconnecting switch are the other names used for isolators and these are found in many forms for different applications.

Comparison Table Between Insulator and Isolator

Parameters of Comparison




A substance preventing the passage of energy.

A device that separates the defective section to avoid further faults which perhaps can be severe.


It prevents the passing of heat or electricity through it.

It is used for isolating any conductor from its source of power.

What is it

Substances like plastic, glass, mica are highly resistant to current or heat.

A mechanical switch at both sides of the conductor.

Works as

Insulators work as a protector or barrier.

Isolators work as a switch that ensures isolation.


To hold a conductor in place for separating it from others.

To stop the flow of energy to other parts by separating the energized part.

What is Insulator?

An Insulator is anything that has the potential to stop the flow of electric current or heat. Although these insulators are considered to be a non-conducting substances, they are better represented as a substance that has high resistance to the heat and flow of electric current. The common use of an electrical insulator is to hold a conductor in its position while separating it from other conductors and the surrounding surfaces.

Insulators create a wall between the parts that have energy and restrict the amount of current that flows to the wires and other parts of a conductor as wanted. The insulation of an electric circuit is necessary for the operation of all electronic and electric devices to be successful. There are many materials available that can act as an insulator, and they are selected based on specific requirements needed for each application. The electrical wiring of homes and industrial plants have a copper conductor in them which are separated from one another by rubber or plastic wrapped around them.

Large motors and generators that emit high temperature and voltage are often insulated with mica. Porcelain insulators are used to support overhead power. Sometimes, solid insulation is combined with the insulation of liquid or gas for some applications. For example, in transforms with high voltage, solid insulation gives mechanical inflexibility, while liquid insulation which is the oil contributes to increasing insulation power and expelling heat from the conductor or equipment.

What is Isolator?

An isolator is defined as a mechanical switch that is used to separate a section of an electrical circuit when needed. These switches are used to open an electrical circuit in its no-load state. The isolators are not supposed to be open when the electric current flows through. Generally, these isolators are attached on both sides of a circuit breaker due to which the repair of the circuit breaker is done without any issue or risk. Isolators; as the name suggests, isolate any type of electrical element from its system when the system is in the offline or online state.

An isolator is also known as a disconnector. It can be operated manually or automatically and sometimes employed with an earthing switch for grounding the portion of the equipment that has been separated from its system to ensure the safety of that equipment and the person working on it. In electrical substations, switches with high voltage isolation are used for isolating apparatus like a circuit breaker, transformers, transmission lines, etc.

An isolator is not intended to control the circuit but is intended for safe isolation. Unlike other load switches or circuit breakers, isolators do not have the mechanism to suppress electric arcs, which occurs when a conductor which is carrying a high electric current is disturbed. This is why, isolators are made as off load devices, which have very low breaking capacity and are only intended to open after the current has been disturbed by another control device.

Main Differences Between Insulator and Isolator

  1. An insulator is a type is a material that does not allow any energy to pass through it whereas, an isolator is a switching device that is used to open or close a circuit.
  2. An insulator is used for holding a conductor in place while separating them from everything in the surroundings whereas, an isolator separates certain parts of equipment or conductor from its source of energy.
  3. An insulator works as a protector whereas, an isolator works as a switch.
  4. Insulators are not mechanical devices but substances like mica, plastic, rubber, glass, wood, etc, while isolators are the two-port mechanical device for transmitting radio frequency or microwaves in one direction.
  5. Insulators prevent the flow of energy which can cause damage by acting as a wall between them whereas, isolators ensure that the electrical circuit does not contain any energy while maintenance.


In conclusion, substances like plastic, wood, mica, etc are forms of insulators that can easily interrupt the passing of energy from one conductor to another whereas isolators simply isolator the whole section that has energy. Where there is the risk to human life, insulators, and isolators though being different work together to prevent any severe damage from happening.

An effective isolator can easily minimize or even stop the flow of current or heat by isolating the energized parts from other parts of the equipment which are not in contact with energy for the time being. Even if some part of that energy gets released to the other parts where it is not required, the insulator components like plastic, glass, etc act as a barrier between the conductor and the personnel operating on it to avoid any risk that could occur when that energy touches that personnel.


  1. https://www.osapublishing.org/abstract.cfm?uri=oe-20-2-1839
  2. https://www.osapublishing.org/abstract.cfm?uri=oe-24-12-12856