While the 10KV power distribution network is increasingly powerful, its structure is more and more complex. During the power distribution network operation, more and more cases of full trip resulted from the fault of the branch line or user equipment, which have become the main factor to affect the power supply reliability of the power distribution network.
Install a user boundary switch (watchdog for short) at the T joint of the above-mentioned user branch or user terminal (responsibility separation point), confirm that the user has the accident (accidents such as over-current, short-circuit and weak current etc.) after judgment, isolate it to ensure to recover power supply for the non-fault user, reducing the outage area and solving the responsibility dispute between the user and power supply bureau.
lThe fully-insulated and fully-sealed structure is used for this product, which is applicable to the various operation environments of the power distribution network around the clock. It is dampproof and condensation, low and high temperature resistant.lIt has the design of a case type integrating the vacuum breaker and three-position disconnecting switch, modularized structure, operating power supply, high power supply reliability, set timing current-limiting and over-current protection, quick disconnection protection and zero sequence protection, instantly cutting the user or branch line fault.
Transportation and Handling
Correct use of the forklift. The cabinet should be fixed if the road is uneven. Please do not stack the articles on the cabinet or tread it. After the external wood box is removed, handle it with the rolling bar. Do not apply force on the insulating parts. The equipment unit can be easily installed after leaving the factory.
The ring main unit can be hoisted with the ring or moved with the fork of the forklift handling lift.
Attention! Because the center of gravity of the equipment unit is high, please take care when handling it. The equipment must be firmly fixed during transportation.
Delivery Taking and Acceptance
After receiving the equipment, please carefully check whether the equipment is damaged during transportation; if yes, you must immediately notify the carrier. When carrying out the inspection after unpacking, please pay attention to the following items:
●Confirm the completeness of the received equipment;
●Inspect the functional components;
●Check the nameplate contents by comparing with the original order;
●When the equipment is received, the packaging should be intact;
●After unpacking, the rest materials (plastic packaging, board and block) may be reasonably used or sent to the appropriate recycling organization.
Before being installed for use, the equipment must be stored in the dry and ventilated places and well covered.
The ring main unit often operates and serves under the normal indoor conditions, complying with the GB11022 standard.
The specific operation limits are as follows:
Maximum temperature +40℃
Maximum temperature (average temperature during 24 hours) +35℃
Minimum temperature -40℃
Maximum average relative humidity (measurement during 24 hours) 95%
Maximum average relative humidity (measurement during one month) 90%
Maximum altitude for which the pressure may be not reduced when installing 1,500m
Special Operation Conditions
Follow the GB11022 standard. The manufacturer and end user should agree on the special conditions which are different from the normal ones. If the special and harsh operation environment is involved, you must consult the manufacturer and supplier in advance.
Step 1: Inspection
1.1 Check whether the switch installation and operation plans are consistent with the design plans.
1.2 Check and confirm whether the switch operation is flexible and all indications are correct.
1.3 Check whether the cabinet pressure falls into the conforming range.
Step 2: Power transmission
2.1 When transmitting the power, please confirm whether the switch is in the disconnection state and operate the switch according to the operation order.
2.2 Notes: Only the incoming line has charge, first close the incoming line cabinet and close the feeder line cabinet one by one, and then transmit the power for the single compartment one time from one side of the incoming side. No connection for several compartments at the same time. No incoming line connection is allowed when the outgoing line is in the connection state. When connecting the switch, the previous switch will have trip resulted from the transient over-current when connecting.
Step 3: Inspection and management
The switch is equipment with free maintenance and no regular overall maintenance and inspection are required.
During the operation, the external visual inspection can be irregularly carried out, with the inspection contents as follows:
3.1 During the operation, the irregular inspection should be carried out for the switch and check whether the coating or plating on the external cabinet surface has scratch, drop or rust;
3.2 Whether the grounding position is flat or has rust and whether grounding is reliably connected.
3.3 Whether the incoming and outgoing line casing has crack and whether the incoming and outgoing terminals have upward or downward distortion.
Whether there is a necessary distance between the main loop inlead and between the outlead and switch hub; it is suggested to clean the external surface of the switch when it is necessary to black out for maintenance.
Before carrying out the mechanical operation, please confirm that the front panel is well installed. When the manual operation is carried out, all switch equipment should be operated by using the operating handle. All mechanisms are designed and manufactured according to the principle of the synchronous action of three-phase linkage; each operating action speed is mutually independent.
There is a mechanical interlocking in the disconnecting load switch/ vacuum switch and corresponding grounding switch to prevent misoperation. The operating handle has a hexagonal hole at one end and multi-tooth hole at the other end. The multi-tooth hole is used for the disconnecting switch and the hexagonal hole is used for other operations. Each operation must be in place and please pay attention to observing the connection and disconnection indications.
Connection and Disconnection Operations of the Grounding Switch