Hammond 178ET 750VA Toroidal Isolation Transformer, 120V Plug-In

The Hammond 178ET is a 750VA plug-in toroidal isolation transformer with a 120VAC primary and 120VAC secondary, rated for 50 or 60 Hz. It provides circuit isolation for integrators, technicians and engineers who want isolated, low-noise 120V power for connected equipment without hard wiring.

The toroidal design is chosen for high isolation, low noise, light weight, cool operation and a low profile. The unit is built in a ventilated black steel case with perforated holes, and includes a rocker lighted on-off switch and a circuit breaker protected output. The 178ET is the 750VA model, stepping up to the larger 10.25 in by 7.50 in by 5.00 in case, with a 7 amp circuit breaker on the output.

The input (primary) connects through a standard North American NEMA 5-15P 3-wire grounded plug; the series specification lists a 5 foot cord, while the part drawing calls out a 6 foot cord. The output (secondary) is two standard 3-wire grounded receptacles (NEMA 5-15R). Overall dimensions are 10.25 in (260 mm) long, 7.50 in (191 mm) wide and 5.00 in (127 mm) high, and the shipping weight is 25.05 lbs (11.36 kg).

The 178ET carries the North American Mark of Safety, C UL and UL listed under File #E211544, and is RoHS and REACH compliant. It is for indoor use only and does not convert line frequency. Because toroidal transformers can draw a high magnetizing inrush when first energized, consider a slow-blow fuse, time delayed circuit breaker or soft start circuitry on the supply line.