INSTRUMENTATION & CONTROL 3. Typical override controller configuration. A protective circuit provided within the DCS is an override to the waterwall temperature controller fuel bias if the main steam, the main steam desuperheater inlet, or the reheat steam temperatures exceed a predetermined value. The function is to protect boiler tubes from excessive temperature and the associated tube life degradation. Courtesy: GenOn Energy TE Override controller Process controller Integral feedback K S d/dt Integral feedback K S d/dt TE Errorhttp://www.powermag.com