My two 15 year old Water Furnace 5 ton units have a switch for 208 or 230. The transformer is a Basler 15P501B01. One unit is set to 208 the other to 230. Which is correct? The switch is in an area where it could have easily been bumped. Thank You
Then set the switch to 230V. 240V is standard residential voltage at the transformer terminals (240V transformer secondary winding with center tap also provides 120V phase-to-ground in your panel). Many motors are rated for 230V which is a typical voltage at the motor terminals under load after considering voltage drop from the transformer to the load. As stated above, 230V is a typical residential voltage level and 208V is commercial. 208V is phase-to-phase voltage typically derived from a 480V 3 phase delta to 208V 3 phase wye transformer which also provides 120V phase-to-ground.