When power outage maintenance is carried out on distribution equipment [including high-voltage distribution rooms, box type substations, distribution transformer racks, low-voltage distribution rooms (boxes), ring main cabinets, and cable branch boxes], the first type of work ticket should be used; Multiple high-voltage distribution rooms, box type substations, and distribution transformer racks can use one work ticket for the same type of work on the same day; When the high-voltage line is not powered off, the person in charge of the work should explain to all personnel that there is electricity on the line and strengthen supervision.
When working on high-voltage distribution rooms, box type substations, and distribution transformer racks, regardless of whether the line is powered off, the low-voltage side knife switch should be opened first; Afterwards, open the high-voltage isolation switch (knife switch) or drop type fuse, and test and ground the high and low voltage leads of the power outage. The above operations do not require the use of an operation ticket and can be carried out under the supervision of the person in charge of the work.
Before homework, check that users with dual power sources and self provided power sources have taken mandatory technical measures such as mechanical or electrical interlocking to prevent reverse power transmission,
At the high voltage system connection point of the user line with dual power supply and self provided power supply, there should be a clear disconnection point to prevent the user equipment from being powered back during power outage operations.
Box type equipment such as ring main cabinets and cable branch boxes should be equipped with electrical and grounding devices.
Before carrying out power outage operations on distribution equipment, all circuit breakers (switches), isolating switches (knife switches), and fuses that may transmit power to the equipment to be repaired and on each side of the distribution transformer (including user lines) should be disconnected, and the work can only be carried out after power verification and grounding.
When two or more distribution transformers share a common grounding lead on the low-voltage side. Any one of the distribution transformers should be powered off for maintenance, and other distribution transformers should also be powered off.
When verifying the power distribution equipment, insulated gloves should be worn. If direct verification is not possible, indirect verification can be carried out according to the provisions of Article 3.3.3.
When carrying out power outage work on capacitors, the power should be disconnected first, and the capacitors should be fully discharged and grounded before starting work.
When the grounding resistance of the distribution equipment is unqualified, insulated gloves should be worn before touching the box.
Power distribution equipment should have anti misoperation locking devices, and anti misoperation locking devices are not allowed to exit operation arbitrarily; Unlocking is prohibited during the switching operation. If unlocking is required, approval procedures should be followed; The unlocking tool (key) should be sealed in a timely manner after use.
Ordinary cable joints used in power distribution equipment are prohibited from being plugged or unplugged with power. Elbow type cable joints that can be plugged or unplugged with power should not be operated under load.
When the charged nuclear phase is on the tower, operators should maintain a safe distance from the charged parts as shown in Table 5-1. The nuclear phase work should be carried out phase by phase.