1. On-site performance
What problems will the mining area see?
- The generator capacity has been increased, but the pressure drop is still significant when the crusher, water pump, air compressor or conveyor belt is started.
- Equipment close to the unit can operate, but equipment far away has difficulty starting, trips frequently, or operates unstable.
- The temporary cables at the expansion site are getting longer and longer, with more and more joints. The problem is more obvious in rainy days, dust or high loads.
- The circuit breakers, low-voltage cabinets and cables still use the old configuration. The main unit has been upgraded to a larger one, but the power distribution system has not been re-examined.
2. Risk causes
The reasons behind the power layout
The generator is only responsible for sending out electricity, and the mining area also needs to deliver electricity stably to the equipment. The capacity of the low-voltage cabinet, circuit breaker setting, cable cross-section, line length and connector quality will all affect whether this part of the electricity can actually be used on site.
When the lines are long, the cables are thin, there are many connectors or the partitions are unclear, the terminal voltage will drop as soon as the starting current of the equipment increases. The host machine still has some spare capacity, but the terminal equipment can no longer be used.
Expansion and phased construction are most prone to this problem. In the first stage, the cables can be temporarily pulled and used. When adding equipment in the second stage, if the power distribution and cables are not recalculated, faults will be concentrated and exposed.
3. Scope of influence
Production suspension, fuel consumption, maintenance, safety and environmental protection will all be magnified
- The equipment failed to start up, and the trial production rhythm was interrupted. The site mistakenly believed that the generator was not big enough, and continued to add the host cost.
- Frequent voltage drops and trips increase the risk of failure of motors, control cabinets, contactors and cable connections.
- Maintenance personnel repeatedly checked generators and equipment, but ignored intermediate power distribution and line problems, which prolonged the downtime.
- Temporary lines carry high loads for a long time, which will increase joint heating, protection malfunctions and potential safety hazards.
4. How to avoid before construction
What do mine owners need to confirm in advance?
- Don’t just check generator kW or kVA. It is necessary to check the low-voltage cabinet, circuit breaker, cable cross-section, line length, connection method and equipment zoning at the same time.
- Draw the power supply path according to the location of the equipment, confirming how far each key equipment is from the power supply, which cables go, and which switches and connectors pass through.
- Before expansion, review whether the old power distribution system can still withstand the new load. If necessary, reserve independent circuits, enlarge cables, or adjust power distribution zones.
- Record the terminal voltage, starting sequence and tripping position during debugging to avoid judging whether the capacity is sufficient just by looking at the data at the generator end.
5. On-site confirmation information
The closer the information is to the scene, the faster the plan will be implemented
- Generator model, capacity, voltage, parallel mode, and photos of existing low-voltage cabinets and circuit breakers.
- The distance from the main equipment to the generator or distribution cabinet, line direction, cable specifications and connector locations.
- The name of the equipment that experienced voltage drop, tripping or startup failure, the startup method and the time when the problem occurred.
- Expansion phase plan, temporary line usage, future new equipment and whether the distribution zoning needs to be adjusted.
