208V to 236V Buck-Boost Transformer — Step-up, Single Phase
See how a 208V to 236V single phase buck-boost transformer corrects voltage and how to select the proper model.
Choosing a 208V to 236V transformer
A 208V to 236V buck-boost transformer raises a nominal 208V supply by roughly 13.5 percent so equipment nameplated for 240V runs inside its design range. The 236V target sits just under 240V on purpose: a 240V heating element or contactor coil sees close to its rated voltage, and there is still headroom if the building service drifts high during light-load hours. On a 208Y/120 service this is the standard correction for 240V equipment that was specified, ordered and installed before anyone measured what the panel actually delivers. Single-phase and three-phase configurations are available in 10 through 60 amp ratings.
The 208 to 240 mismatch appears wherever the equipment is chosen from a catalog and the building is chosen by a landlord. Restaurants, strip malls, schools, medical offices and multi-tenant industrial condos are nearly always fed 208Y/120, while the equipment those tenants buy is built for 240V.Commercial kitchen equipment: fryers, convection and combi ovens, griddles, booster heaters and dishmachine tank heaters, all resistive and all of which lose output on 208V.Refrigeration: walk-in cooler and freezer condensing units, ice machines and remote compressor racks whose nameplates read 230/240V.Rooftop units and split-system condensers dropped onto an existing 208V roof feed during a tenant fit-out.Storage and point-of-use water heaters, duct heaters and process heat where recovery time is written into the spec.Imported and packaged machinery built around a 240V power and control scheme.The pattern repeats in every case. The load runs, more or less, but never performs the way the submittal promised, and the fault gets pinned on a bad appliance rather than a supply that is 13 percent low.