Subtraction of foreign projects

Mobile payment is not popular abroad. Chinese people value simplicity and convenience, while foreigners value safety and reliability. This is closely related to their living environment, historical origins, and so on. We cannot impose our own thinking on foreign customers.

Each product has its own application scenario, such as IEEE C37.20.3 medium voltage switchgear, UL891 low voltage distribution panel, user side switchgear. Customers only need to perform opening and closing operations, which is simple and safe, without the need for complex functions and operations. Adopting mechanical key interlocking to ensure operation sequence and safety requirements.

The reliability of a product is the reliability of the entire system, and the reliability of a system is the product of the reliability of each part. Even if each part has a reliability of 99.9%, the five parts only have 99.9% × 99.9% × 99.9% × 99.9%=99.5%. If a part has a reliability of only 60%, the reliability of the entire system will decrease to 59.7%. Our product likes to add various useful and useless functions, and each function will affect the reliability of the entire system.

The same applies to safety, the barrel effect. The overall safety level depends on its weakest link, the ability to resist internal arcs, which often cannot withstand the impact of internal arc faults due to the installation of electromagnetic locks, lighting fixtures, etc. on the door panels.

Therefore, many foreign projects do not use these additional devices, and some countries even do not require cable room observation windows. The entire cabinet is covered with a sturdy welded cover plate, which is sturdy and safe. Alternatively, to ensure the ability to withstand internal arc faults, it can be divided into three cover plates.

Unlike the bus side voltage transformer, the lower cable room voltage transformer handcart does not use a separate compartment, does not require valves and contact boxes, and does not use a chassis cart. The principle is that regardless of whether it is on the incoming or outgoing side, the voltage transformer is part of the cable room and is directly connected to the copper busbar. Generally, the high voltage in the cable room needs to be cut off and grounded before entering the cable room, and then the voltage transformer handcart can be pulled out and inserted. Once in place, the contact head can directly touch the high voltage busbar, and the handcart can be locked.

Bolt lock, directly use stainless steel bolts as door lock bolts. The anti arc capability of the switchgear. The cabinet must be strong enough, and the welding of door panels and other components must be sturdy enough to truly resist internal arcs. Sometimes the design can meet the requirements, but due to welding, assembly, etc. not meeting the requirements, the product may also fail. Increasing the thickness of the board, adding more bolts, and increasing the number of hinges will not increase the cost much, but will instead increase the customer's sense of security and satisfaction. Quick opening of door locks is not the preferred solution for foreign projects. The complex handle driven locking mechanism can cause the door to fail and fail to open. Moreover, many quick opening door locks have weak strength and are virtually useless, lacking the ability to resist internal arcs. Simple and reliable bolt locks are even more reliable.

Generally, there are no lead cabinets, metering cabinets, or incoming circuit breaker cabinets for power supply bureaus. Instead, voltage transformers and current transformers are directly added to the incoming circuit breaker for metering. Current transformers and voltage transformers are not installed on a handcart, and dedicated metering secondary compartments are installed.

Without using an isolation handcart, the busbar lifting scheme is directly used for connecting with the busbar circuit breaker. The lifting cabinet can be equipped with a busbar voltage transformer and a busbar grounding switch, reducing the number of switchgear. The one-time solution is simple and practical, reducing the number of switchgear and simplifying the solution while meeting the electricity demand.  

Bus bridges are rarely used in foreign projects, and cable connections are widely used. For example, in high current incoming cabinets, 3150A will use 5 400 square cables per phase to connect to transformers.