According to the NFPA70E, an arc flash hazard risk category of “DANGEROUS” is a very severe risk / hazard level and cannot be worked on while energized—i.e. you must de-energize from an upstream device.
These levels of hazards are extremely severe, from both an equipment standpoint and more so from your employees standpoint. Mitigating these levels of hazards require attention to details, good engineering practices and honestly common sense. There are many ways to mitigate these levels of arc hazards and we have the experience to assist you with mitigating your high hazard levels.