AbstractWithin the ‘earliest phases of star formation’ (EPoS) Herschel project, we observed the NH₃ inversion lines of 6 very young high-mass star-forming regions at high spatial resolution (3-5″) with the JVLA. While the Herschel data provide details about the dust continuum, the ammonia data reveal the kinematics and temperatures. Here we present the exciting star-forming clump ISOSS23053 that shows multiple velocity components. We observe a prominent velocity step within the clump, which could be a sign of colliding or converging flows that triggers star formation. Furthermore, we used the JVLA in the C-array configuration to study this source in more detail and we present the first results from the new data. They support the idea of converging flows, as we observe two components in the NH₃(1,1) and (2,2) line, whereas the higher excited NH₃(3,3) line shows one component that links the two lower excited lines.