This paper introduces the safety precautions in the debugging process of power distribution cabinet in detail.

The commissioning of power distribution cabinet is a high-risk electrical operation, involving power-on test, high-voltage equipment operation and other links. Safety regulations should be strictly observed to avoid accidents such as electric shock, fire and equipment damage. The following are the safety precautions that need to be paid attention to in the debugging process, which are explained from the perspectives of personnel, operation and environment:

A, personnel qualification and protection requirements

Certification and training

Debugging personnel must hold the low/high voltage electrician operation certificate (depending on the voltage level of the distribution cabinet), and unlicensed personnel are prohibited from participating in the operation.

Before operation, safety technical disclosure shall be conducted, and the commissioning scheme, equipment principle and emergency plan shall be familiar with, and personal responsibilities (such as operator and guardian) shall be defined.

It is forbidden to work under the influence of alcohol, fatigue or illness, and keep your attention during debugging.

Personal protective equipment (PPE)

Required equipment:

Insulating gloves (need to pass the pressure test, regular inspection), insulating shoes (soles are not damaged).

Safety helmet (with insulating lining), non-slip work clothes (non-chemical fiber material to avoid static electricity).

Optional equipment:

Goggles (to prevent eye injury caused by arc splashing, especially when debugging the high-voltage cabinet).

Anti-arc suit (for scenes where arc may occur, such as high-voltage switch test).

Second, the safety confirmation before debugging

Power failure and electricity inspection

Before commissioning, all superior power supplies (such as substation outlet switch and transformer primary side power supply) must be disconnected, and * * warning signs "No closing, someone is working" should be hung at the switch, and lock management should be added if necessary.

Use qualified electroscope (voltage grade matching) to check the incoming terminal and bus bar of the power distribution cabinet, and confirm that there is no voltage before the subsequent operation.

Grounding and Anti-reverse Power Transmission Measures

Ensure that the PE line of the cabinet is reliably grounded, and the grounding resistance is ≤4Ω (which can be measured by a grounding resistance tester).

If there are dual power supply, standby power supply or distributed power supply (such as photovoltaic and generator), it is necessary to disconnect all circuits (such as contact switch and standby incoming switch) that may reverse power transmission, and hang warning signs.

Environment and equipment inspection

Clean up flammable materials (such as paper and oil stains), accumulated water and sundries within 0.8m around the power distribution cabinet, and keep the passage unblocked.

Check whether the cupboard door, partition and fence are complete, so as to prevent the live parts from being touched during debugging; Confirm that the terminal strip and components are installed firmly, and there is no risk of loosening and falling off.

Third, the operation specification in the process of debugging

1. Safety points of power outage operation (when the primary circuit is not electrified)

It is forbidden to work by one person: at least two people shall cooperate, one person shall operate and one person shall supervise, and the guardian shall not participate in other work.

Tool management: Use insulated tools (such as insulated screwdrivers and wrenches), and the handles of metal tools should be wrapped with insulating tape to avoid touching adjacent live terminals by mistake.

Line inspection:

When testing insulation resistance, it is necessary to disconnect capacitors and electronic components (such as frequency converter and PLC) to prevent damage to equipment.

When removing or shorting fuses and relay coils in the secondary circuit, it is necessary to mark them well to avoid wrong connection during recovery.

2. Safety points of power-on test (when the primary circuit is charged)