Attached Figure compares UPS and IPS noise below 50Hz as measured by sniffers in CB (all three phases) and MC. The probes seem all calibrated since the 50Hz peak amplitude matches. It seems that the UPS of CB is ten times more noisy (below 50Hz) than UPS in MC, and hundred times more noisy than IPS. Might be that UPS machines are indeed noisy and CB machine is more noisy than MC one.
It seems interesting to understand and investigate more about this noise.
