In total, over 5700 changes to the BLM thresholds were made during 2015. The new thresholds are based on the operational experience from Run 1, on new simulation models and on results from quench tests performed so far. Following the first experiences with operation at 6.5 TeV, a series of adjustments were made throughout the first operational year of Run 2. An overview of the main changes since the start of the LHC operation and their impact on the machine protection will be presented, focusing on the impact on availability during operation in 2015. The paper will conclude by discussing the remaining main updates, and by proposing a threshold strategy for the start-up in 2016. BEAM LOSS MONITORING SYSTEM At the beginning of Run 2, the beam loss monitoring (BLM) system had 3929 detectors out of which 3518 were connected to the Beam Interlock System (BIS). Although there are three types of detectors employed by the LHC BLM system, only Ionization Chambers (IC) are connected to BIS. The two other types, LIC (108 in LHC) and SEM (191 in LHC) are currently installed for additional measurement purposes [1]. Among the changes to the BLM system between Run 1 and Run 2, there were the relocation of 816 detectors from the side of MQ magnets to on top of the interconnects of the MB magnets in ARCs and DSs, and the replacement of SEMs with LICs in the injection regions (IR2 and 8).
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