Why do we Isolate Circuits?

Electrical isolation is crucial in various scenarios to ensure safety, prevent electrical interference, and protect sensitive components. Isolation refers to the separation of electrical circuits or components from each other. There are several reasons why isolation may be necessary:

  • Safety: Isolation is vital for preventing electric shock.  Isolating circuits can minimize the risk of electrical accidents and protect individuals from harm
  • Noise and Interference Reduction: Isolating circuits can help reduce electrical noise and interference. In sensitive electronic systems, unwanted electrical signals can degrade performance or cause malfunctions. Isolation helps prevent these signals from affecting other components or circuits.
  • Ground Loop Prevention: Ground loops occur when there are multiple paths to ground in a circuit, leading to unwanted currents and potential issues such as noise, interference, or even equipment damage.
  • Component and Circuit Protection: Isolation can protect sensitive components from damage caused by voltage spikes, surges, or faults in other parts of the system. By isolating certain circuits, you can contain these issues and prevent them from spreading to other components.

Three main types of circuit isolation exist - Electro-mechanical, optical and magnetic.

Electromechanical Isolation involves devices like contactors and relays. They have coils connected to one circuit and contacts connected to another - the separation is thru the electromechanical device.  When the coil is energized, the contacts change state (open to closed or closed to open).  The two circuits never connect directly and provide a barrier between them for safety and control.

Optical isolation involves an optocoupler - it is a device that has an LED (light emitting diode) and a photodiode imbedded within it.  When the LED is illuminated, the photodiode turns on as a result - the two components are not connected - they are located within a small proximity of each other separated by a very small distance.  These devices are used mainly with digital circuits that are either on or off - high or low.  Again these two circuits are not connected and ensure safety and control.

Magnetic isolation is achieved with the use of transformers.  Transformers connect two different circuits magnetically.  Input voltage, say 440VAC and control voltage, 120 VAC would be a good example of this.  Again there is separation of the two circuits but more directly than the two cases above.  Changes in one circuit can definitely impact the second circuit in this example.

American Electrical, inc. (AEI) sells many types of contactors and relays that provide the #circuit #isolation you may need for your next design or retrofit.

Please visit our site here for Contactors


And here for Relays


All of the products we sell are in stock and ready to ship in Richmond, VA. Call us at 804.379.2899

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