During the switch off of electronic equipment in EE-room (December 3rd) we see disappearing some sideband noise around 100Hz (Figure 1) and 200Hz (Figure 2) in CEB UPS, as well as in CEB magnetometers and Electric probe (that was measuring the voltage noise between EE-room electrical equipement ground and Virgo ground (Figure 3). In particular these are the inner sidebands peaking at 98.9 Hz and 101.1 Hz. Possibly this is associated to the switch off of thechiller cooling the beam dumps (but to be verified).