Three phase Isolation transformers have a wide range of applications - grain dryer, saw mills, conveyer belt systems, refrigeration, air conditioning etc. Isolation Transformers are so called because the primary and secondary windings are physically separated from each other. Isolation transformers fitted with electrostatic shields are used for power supply for hypersensitive equipments such as computers or laboratory instruments. Hospital Grade Isolation transformers ideally protect sensitive electronic equipment in patient-care areas.

In electronics testing, troubleshooting and servicing, an isolation transformer is a 1:1 power transformer is used as a safety precaution. The shield three phase isolation transformer is preferred over the standard three phase isolation transformer because it provides protection to sensitive and critical equipments. When more that one shielded 3 phase isolation transformer is used between the source and the load, it considerably improves power quality.

Of course, all transformers provide isolation. They are constructed with a primary and secondary winding closely wrapped around the same ferrous core. Commercial transformers incorporate a single Faraday shield between the primary and secondary windings to divert noise. Three phase isolation transformers have three primary and three secondary windings that are physically separated from each other. Isolation transformers are different from auto transformers in which the primary and secondary share a common winding.

An isolation transformer is designed to overcome problems associated with referencing its internal shields to ground. It is constructed with two isolated Faraday shields between the primary and secondary windings. When rightly installed, the shield, which is closest to the primary winding, is connected to the common power supply ground and the shield closest to the secondary winding is connected to the shield of the circuit to be isolated. The use of two shields in the building of the isolation transformer diverts high frequency noise.

In isolation transformers the primary and secondary windings may be engineered to step-up or step-down the output voltage. For example, the transformer can accomplish voltage matching between a 120 V load and an electrical system that measures 208 V. Isolation transformers constructed with Faraday shields, do improve power quality by minimizing higher frequency noise currents and reduce the cumulative leakage current of the Isolator and connected equipment to levels below 300 micro-amps. In an isolation transformer the output winding will be isolated, or floating from earth ground except if bonded during the time of installation.

A special feature of isolation transformer is it allows an AC signal from one device and fed into another without electrically connecting the two circuits. Isolation transformers obstruct transmission of DC signals from one circuit to the other, but allow AC signals to pass.

The Shielded three phase isolation transformers have all the features of the standard 3 phase and additionally they also incorporate a full copper/aluminum shield between the 3 phase primary and 3 phase secondary windings. This electrostatic shield or Faraday Shield is connected to earth ground to help minimize/filter voltage transients / voltage spikes. These shielded 3 phase isolation transformers have an attenuation ratio of 100 to 1.