Grant Transformers supplies high quality isolation transformer and innovative products with performance guarantees and flexible designs.

An isolation transformer is a transformer which is used to decouple two circuits, with the transformer coil windings designed for an input/output voltage of 240/240V for example. Isolation transformers allow an AC signal or power to be taken from one device and fed into another without electrically connecting the two circuits. Isolation transformers block transmission of DC signals from one circuit to the other, but allow AC signals to pass. They also block interference caused by ground loops. Galvanic Isolation is a superior and reliable solution with based on the benefits of capacitive de-coupling derived from winding the primary and secondary with an earth screen.

Isolation transformers with electrostatic shields are used for power supplies for sensitive equipment such as computers or laboratory instruments. Differential noise can magnetically couple from the primary to the secondary of an isolation transformer. This requires other measures, such as a filter, to block differential noise from the secondary of an isolation transformer.

Note: Grant Transformers Isolation 240/240V transformers include a grounded shield between the primary and the secondary windings as a standard accessory (E/S Models). This screen has a very high coupling to the input winding. Hence it reduces common mode noise on the 240V input side.


These isolation transformers are supplied as open type transformers typically for switchboard applications or standard isolation transformer IP23 rated. Grant Transformers can supply up to IP66 isolation transformers for outdoor use or wet applications.

Isolation transformers are also used for the power supply of devices not on ground potential as one option.

Optional Extras: Our isolation transformer units can include an On/Off Switch as well as Electrostatic Screening and displays and temperature monitoring. Single Phase Isolation Transformers and Three Phase Isolation Transformers are manufactured to customer specifications in Australia.

Standard power rating 1VA to 1000kVA
Standard primary voltages 240V, 415V, 440V, 690V, 1000V, 3300v, 6600v
Standard secondary voltages 12V, 24V, 32V, 110V, 240V, 415V, 440V, 690v, 1000v
Insulation Class F & H
Copper Windings
Mining, Military, Rail type standard transformers with center tap and earth shield
Extra voltage taps available upon request
Other voltages, ratings and insulation classes available
Built and tested to AS/NZS 61558 and AS/NZS 60076
Every unit is 100% tested (no batch testing)
Transformers have a minimum 1 year warranty
Manufactured at our factory offering fast turnaround time for urgent projects