Operation precautions for Low voltage power distribution switchboard
1. Separate the equipment going to be maintained with the working equipment with obvious mark when doing work on live panel or part-live panel.
2. There should be permanent and reliable protection grounding for secondary winding of CT and PT.
3. The following measures should be made when work on secondary circuit of working CT.
3.1 Forbid opening current circuit.
3.2 Use short-circuit plate and short-circuit line to make secondary winding of CT short circuit reliably. Using leading wire to wrapping is forbidden.
3.3 Working on the circuit between CT and short-circuit terminal and leading wire is forbidden.
4. Do the following safety measures when work on secondary circuit of working PT:
4.1 Short-circuit or grounding should be avoided.
4.2 Use insulation tools, wear insulation gloves or stop the working of relative relay protection devices before work if necessary.
4.3 Install special switch and fuse when connect with temporary load.
4.4 When doing electrifying test on secondary circuit, open secondary circuit and take off fuse at primary side to prevent voltage from secondary side to primary side.
4.5 Before supply power to secondary circuit or doing voltage withstand test, inform operators on duty and relative people, send people to site, check circuit, then increase voltage when there is no people working.