I’d like to ask for opinions on a theoretical scenario to clarify best practice.
Imagine there’s a large motor powering a large water pump on site, supplied via a 3-phase circuit with a 125A 40kA BS88 Gg fuse. The fuse on the red phase has blown.
The person on site holds the 18th Edition qualification but has limited hands-on experience. They have confirmed (under full LOTO conditions) that the motor is freely spinning and the pump hasn’t seized. A subcontractor has advised them to simply isolate the supply, replace the fuse, and re-energise the circuit. However, the site manager (25 years’ experience and 2391 qualified) has stated that the circuit must be tested first to determine the cause of the fault before restoring power.
The subcontractors are insisting it’s the on-site person’s job and are pressuring them to just swap the fuse.
My view:
I would go with the manager’s advice and insist on testing prior to replacing the fuse. Simply swapping the fuse without investigating could mask an underlying fault and lead to further damage or safety risks.
Questions:
What would your opinion be in this situation?
What guidance or regulations would you reference to support your view?
