230V to 208V Buck-Boost Transformer — Step-down, Single Phase
See how a 230V to 208V single phase buck-boost transformer corrects voltage and how to select the proper model.
Choosing a 230V to 208V transformer
A 208V-rated machine sitting on a 230V service is the most common reason to step down 230 to 208. Equipment ordered on the 208V voltage code, or moved out of a building with a 208Y/120 service into one fed at 230V, sees about 10% more voltage than its nameplate was designed around. A 230V to 208V buck-boost transformer corrects that difference. Because it is an insulating transformer reconnected as an autotransformer, and processes only the 22V difference rather than the full load, it is far smaller and cheaper than an isolation transformer rated for the same amperage.
This correction shows up most often in packaged HVAC and commercial refrigeration. A rooftop unit, condensing unit or walk-in cooler package gets ordered on the 208V voltage code because the tenant space was assumed to be 208Y/120, then arrives at a building whose service is 230V. Swapping the equipment is rarely an option once it is sitting on the curb, so the voltage gets corrected instead.Other recurring situations:Commercial kitchen equipment specified at 208V (combi ovens, dishwashers, proofers, holding cabinets) installed in a space fed at 230V.Equipment relocated between buildings, or bought used from a facility that had a 208Y/120 service.Multi-tenant retail and strip centers where the landlord's service differs from what the equipment package was quoted against.Shop and lab equipment, dental compressors, imaging gear and irrigation controls built around 208V.Resistive loads are the least forgiving of the group. A 208V heating element on a 230V supply dissipates roughly 22% more power than rated, because element power rises with the square of the applied voltage.