What are the strengths and weaknesses of T connection and connection?????????????

Both "t" and "" are ways to eliminate power to a third party.

"t" connection refers to the indirect supply of a line from the line supplied by Party A to Party B to supply power to third party C; Since it is connected from the line that supplies power to others, from the "look" of power supply A, this line is quite a two users, Party B and Party C. It is precisely because it is connected from the middle of the line "T" that its operation is not affected by the operation mode of Party B; The reliability of power supply is the same as that of Party B; At the same time, because they are independently powered, the protection setting and setting are relatively simple.

The " connection is connected from the bus of Party B's substation, and the outlet switch of Party C is an outlet line of Party B's substation. From the power supply A to "see" the past, the line only carries the load Party B, and from the substation of Party B and then down to "see" the load C. Therefore, the operation of Party C is affected by the operation mode of Party B; The power supply reliability of Party C's operation is significantly lower than that of Party B. At the same time, because the power supply is supplied to Party C through the bus of Party B's substation, the protection setting and setting of Party B's substation become complicated.

Addendum: There are some good exceptions, but I personally don't like this way.

1. Compared with the T connection, because there is an extra level of switch, although the investment is high, there is an additional level of protection, and the protection effect may be better, or the selectivity is better.

2. It is easier to connect to the "ring network" power supply, and the ring network can be supplied in both directions, and the reliability of power supply is theoretically higher.

But this method can be used inside the power system, the power system is not afraid of complex wiring, complex operation, protection methods, excessive investment, etc., and I am responsible for the users, these users care very much, may be all shortcomings.

I just know that this is the equivalent of the two power lines, which is used for calculations. I've never heard of it really being like this.

This is different in the way the system is accessed.

T connection is to directly connect the new system to the original old line.

The latter is called "breaking loop", also known as "bridging", which is to cut off the original old line and connect the lines at both ends through the bus of the new system.

Obviously, it is more troublesome to break the loop than to connect it to T, but for the new system, the tightness and reliability of the system connection are greatly improved.

High-voltage lines usually refer to transmission lines that transmit voltages of more than 10kV (including 10kV). According to the GBT, the definition states that the high voltage does not usually contain 1000V. The voltage levels of China's domestic high-voltage transmission lines are generally divided into:

35kv, 110kv, 220kv, 330kv, 500kv, 750kv, etc.

The minimum distance between the line and the ground, in the case of the maximum calculated sag, should not be less than the following values:

The low-voltage line (380V) shall not be less than 6 meters through residential areas, and the low-voltage line (380V) shall not be less than 5 meters through non-residential areas;

Medium-voltage lines (6-10kv) through residential areas are not less than meters, and medium-voltage lines (6-10kv) through non-residential areas are not less than meters;

The 35 110kV line shall not be less than 7 meters through residential areas, the 35 110kV line shall not be less than 6 meters through non-residential areas, and the 35 110kV line shall not be less than 5 meters through areas with difficult traffic;

The 154 220kV line passes through residential areas not less than meters, the 35 110kV line passes through non-residential areas not less than meters, and the 35 110kV line passes through areas with difficult traffic not less than meters;

The 330kV line is not less than a meter through residential areas, the 35 110kV line is not less than a meter through non-residential areas, and the 35 110kV line is not less than a meter through areas with difficult traffic.

There is no clear distance regulation between the high-voltage line and the residential building in China, but there is a relevant standard that can be converted: the magnetic induction intensity of the location of the residential building < 100 microtesla, which meets the construction standard. Measured:

The safety distance of the high-voltage line below 1kV is 4 meters;

The safety distance of 1-10kv high-voltage line is 6 meters;

The safety distance of 35-110kv high-voltage line is 8 meters;

The safety distance of 154-220kV high-voltage line is 10 meters;

The safety distance along the 350-500kv high line is 15 meters.

To put it simply, the transmission and transformation line trajectory is the route map of the power supply of a transmission line from substation A to substation B (or the access substation room of the power consumption unit), that is, the path traveled by the transmission line. Track points are "nodes" on that path, similar to network nodes in electroengineering. The track point type T contact, contact, ordinary contact, grounding point, etc., refers to the connection method of the main line and the branch power supply line.

For example, a transmission line supplies power from a substation to a substation B, if it also needs to supply power from a substation to a substation C, in order to reduce investment, a transmission line is connected from a substation to a substation B in the middle of the transmission line, and it is supplied to substation C, then the way to connect another line from the main line is vividly called the "T" connection mode, and this connection point is called "T contact", and the C substation is the third place where the line is accessed.

If there are two such T-contacts, it constitutes a type connection. And so on, there can also be comb connections. You can look for books on this subject and it will be clearer.

Both the piercing clamp and the T-terminal need to strip off the outer sheath of the cable, but the piercing clamp does not need to strip off the insulation layer of the cable back to each core, and the T-terminal needs to remove the insulation layer of each core of the cable.

The contact surface of the puncture wire clamp is small, the firmness is poor, and the construction is simple and fast.

The contact surface of the T-junction is large, and the installation is firm and reliable, but the construction is relatively difficult.

The function of the T terminal block is basically the same as that of the DU pre-branch cable and the puncture ZHI clamp, and each has its own advantages.

The pre-branch inner cable is produced in the cable production capacity.

At the time, the branch cable will be pre-made, and the branch wire will be directly branched during construction. The advantages are the most stable, the disadvantages are the highest, and the calculation is difficult and laborious.

The piercing clamp is to use the built-in piercing blade to open the sheath, pierce the cable insulation, snap into the main cable (in contact with copper), conduct electricity, and then penetrate the distribution port in the clamp to access the distribution cable.

The T-terminal does not have a piercing blade, and needs to be stripped of the sheath and insulating skin. To put it simply, it is the principle of ordinary installation of sockets, which conducts electricity by crimping bare wires.

The puncture clamp is relatively large, the installation is simple and crude, the location of the electric well is large, and the cable model is very useful. The small size of the T-terminal is suitable for use in tight locations, even in the tray. Both can also be used together.

The piercing clamp does not need to dial the skin of the main line, and the T terminal is required.

The insulated piercing wire clamp is mainly composed of a reinforced shell, a piercing blade, a sealing gasket, a waterproof silicone grease, a high-strength bolt, a torque nut and an electric.

When the cable needs to be branched or connected, the cable branch terminal is inserted into the waterproof terminal cap cover, after determining the position of the main line branch, use a socket wrench to twist the torque nut on the wire clamp, the contact blade will pierce the cable insulation layer in the process, contact with the conductor, the sealing gasket ring pressure around the cable puncture position, the silicone grease in the shell overflows, when the torque reaches the set value, the nut torque mechanism falls off, the main line and the branch line are connected, and the waterproof performance and electrical effect meet the parameters required by the standard.

The T-terminal is composed of three parts: insulating base, junction frame and fireproof cover, and the junction frame is composed of wire clamps, screws, nuts and variable bearing frames and other parts. Through the combination of different shapes of wires, a double-layer connection can be formed, the lower layer is connected to the trunk line, the upper layer is connected to the branch line, and the trunk line is continuously connected in a "T" shape, and the product is a protective cover, especially suitable for use in narrow places such as cable tray and cable shaft, which can effectively prevent the harm of rodent infestation to the line.

The main cable adopts the branch cable from the T junction box, and there are two wiring methods:

1. Direct. You don't need to calculate the reserved margin with the T terminal wiring, just clamp it with a puncture wireJust count the number of pieces.

2，.If you use a T-terminal box, you need to calculate the reservation.

At the junction, a cable head needs to be calculated to make a margin, which is to prevent the branch cable head from being repaired after poor contact and overheating damage due to some reason.

There is no requirement, as long as the voltage drop meets the requirements.

"T-connection" and "connection" are the two ways to connect the power supply and the load.

The so-called T connection and connection are very vivid methods of grid connection.

The horizontal above T is the main line network, and the vertical below is the line you want to lead over, so how to connect it, it is connected through the T terminal.