A drilling machine was being used to drill a 76-mm-diameter hole for the overflow pipe in the concrete wall of the septic tank’s buffer tank. (repair construction)
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After drilling the hole, the injured person used his hands to manually turn the handle on top of the drilling machine’s guide gear in order to retract it.
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When he did so, the power cable got caught between the guide gear and the drilling machine, stripping off its sheath, causing a short circuit and giving him an electrical shock.