Can you use an impact driver on MCB’s? The short and only answer is no, defiantly not. Here we discus the reasons why you SHOULD NOT use an impact driver for consumer unit terminals, or any electrical terminal/connection for that matter.
When we refer to “Impact Driver” this is to also include electric/battery screwdrivers and drills used to tighten electrical terminations and connections.
Over tightening of an MCB terminal could damage the MCB, therefore there is a possibility the MCB will not function as it was designed to, if at all. In addition to effecting the design operation it could also damage and crack the actual casing of the miniature circuit breaker.
Under tightening can cause loose connections resulting in arcing, overheating and in the worst case scenario lead to a fire.