When looking to reduce arc energy levels, the first port of call is to review the current protection settings and see if they can be reduced.
For example, transfomer protection settings are usually set to 1.5 times the transformer rating. This may not be a true reflection of the actual load on the transformer so it may be possible to reduce the protection settings.
Instantaneous protection settings may not always be used, again it may be possible to set these at a value which may reduce the arc energy levels.
Discrimination is usually adopted on feeders, this again should be checked as it may be set at an inappropriate level. It may also not be applicable, for example, a transformer primay feeder does not really need a high level of discrimination if there is also only one secondary feed out of the transformer.
Once protection settings have been altered, these new figures must be fed back into the analysis to calculate the new arc energy levels.