Based on extensive field feedback, it is evident that in current operations of urban utility distribution transformers and rural distribution transformers, some low-voltage connections are directly connected to the circuit without the use of disconnect switches and circuit breakers. This setup introduces unsafe factors in maintenance and repair, posing significant risks of personal and equipment accidents. Whether it's the counterintuitive design from the design institute or the substandard power supply schemes from the power supply department, not installing circuit breakers and disconnect switches on the low-voltage side of transformers leads to several hazards, which can be summarized as follows:

1. Challenges in Inspection and Maintenance: The absence of an isolation switch on the low-voltage side complicates circuit inspection and maintenance. Without an isolation switch, other connected equipment or facilities cannot be independently isolated from the power source, increasing risks and difficulties for maintenance personnel.

2. Rural Distribution Transformers During Irrigation Season: To minimize energy losses, the high-voltage side circuit breaker of the transformer is opened after temporary shutdowns. Without disconnect switches and circuit breakers on the low-voltage side, transformers are vulnerable to lightning strikes during thunderstorm seasons.

3. Personal Safety Hazards: When equipment requires maintenance or replacement, the absence of an isolation switch forces maintenance personnel to operate under live conditions, significantly increasing the risk of electric shock. For instance, during transformer maintenance tests or adjustments to tap changers, without a disconnect point on the low-voltage side, inadvertent backfeeding can result in severe injuries or fatalities.

4.Faults on the Low-Voltage Line:

l Inability to Quickly Isolate Fault Points: In situations where fuses are improperly matched, the fault outage area can expand.

l Inability to Disconnect Low-Voltage Side: Only the high-voltage side circuit breaker can be opened, potentially causing arc flashovers, burnt contacts, melted wires, and damaged insulators.

l Power Loss: Without an isolation switch, maintenance or repair of equipment or cables necessitates cutting off the entire area's power supply, leading to power loss for all electrical devices in the area.

Consequently, distribution panels should be installed on the low-voltage side of transformers. Transformers at load centers should have circuit breakers and disconnect switches installed on both sides along the line direction. Surge arresters should also be installed on each outgoing line to protect against overvoltage and lightning strikes. The absence of disconnect switches and circuit breakers on the low-voltage side not only complicates maintenance and inspection but also increases personal safety risks and equipment damage risks.