Global and local power balance studies in ohmic and ECR-heated plasmas in the RTP tokamak (R0=0.72 m, a=0.16 m, BT=2.14 T) are reported, and compared with models. In ohmic plasmas the energy confinement time is consistent with the Goldston-ohmic scaling law. Using ECRH, high Te and Del Te are obtained. An updated version of the Rebut-Lallia-Watkins transport model successfully describes chi eeff in these extreme plasma conditions. Improved confinement ( tau EECRH=2 tau EOmega ) is observed in low-density, low-current plasmas when the ECRH power is comparable to the ohmic input power.