1. On-site performance
What problems will the mining area see?
- There are generators on site, but when the grid or main power supply is shut down, drainage pumps, communications, lighting, ventilation or tailings equipment are still shut down.
- After a power outage, only manual closing, pulling, and load redistribution are required. The recovery speed depends on the experience of the personnel on duty.
- The generator can be started, but I don’t know which equipment to bring first. The key pumps are mixed with ordinary workshop loads to grab power.
- The ATS, switch cabinet and cables have been installed, but the switching logic has not been written clearly. In the event of a real power outage, temporary judgment is still required on site.
2. Risk causes
The reasons behind the power layout
Many mining areas regard “having a generator” as “having a backup”. In fact, the backup power supply needs to be clearly defined first: whether to temporarily provide the entire mine, or only to protect critical loads such as drainage, communications, lighting, ventilation and tailings.
If main, backup, critical power and non-critical loads are not separated, the generator may be connected to the wrong location during a power outage. After the main power supply is lost, key equipment does not have an independent circuit and cannot be restored first.
ATS Buying a switch alone will not solve the problem. The switching sequence, load priority, loop zoning, delayed start and manual bypass must be planned in advance, otherwise power outage recovery will still rely on temporary operations by on-site personnel.
3. Scope of influence
Production suspension, fuel consumption, maintenance, safety and environmental protection will all be magnified
- The shutdown of drainage, ventilation, communications, lighting or tailings equipment that should continue to operate will bring safety and environmental pressures in addition to the shutdown.
- The recovery process is slow. On-site users need to find switches and judge the load at the same time. A power outage may interrupt production for several hours.
- Manual switching is prone to misoperation and may load loads that should not be loaded first, thereby squeezing out the power margin of key equipment.
- The management thought that a backup power supply had been configured, but in actual power outage, key equipment was not protected, and the division of responsibilities and on-site command would become chaotic.
4. How to avoid before construction
What do mine owners need to confirm in advance?
- First divide the power supply in the mining area into main power supply, backup power supply, critical power-guaranteed loads and non-critical loads. Don’t just write a backup generator in the equipment list.
- Identify what equipment must be restored first in the event of a power outage, such as dewatering pumps, tailings pumps, communications, lighting, ventilation, security monitoring, and necessary control systems.
- Make key loads into clear circuits, and cooperate with ATS, circuit breakers, delayed start and load priority to prevent the backup power supply from being occupied by ordinary loads.
- Conduct a power outage switching drill before going into production to confirm that automatic switching, manual bypass, recovery sequence and on-duty personnel operations can all be implemented.
5. On-site confirmation information
The closer the information is to the scene, the faster the plan will be implemented
- The existing main power source is the power grid, diesel generator, parallel system, or temporary construction power supply.
- Photos of backup generators, ATS, low-voltage cabinets, switches, critical circuits and cable access points are available on site.
- A list of equipment that must maintain power during a power outage, as well as the allowable power outage time and startup method of each equipment.
- Recovery records after past power outages, including manual switching steps, recovery time, and which devices were unable to start in time.
