Installation method of zero sequences current transformer

Zero sequences current transformer is used in 66kV and below voltage systems to detect zero-sequence current. Generally, all three live wires are passed through the inner hole of the transformer to measure the vector sum of the three-phase current, which is the zero-sequence current. . Under normal conditions, the primary current of the zero-sequence current transformer is very small, but under abnormal conditions, the zero-sequence current will also be very large. This requires a wide range of zero-sequence current transformer measurements. Therefore, the zero-sequence current transformer usually allows a larger multiple of overload, and the overload capacity is reflected by the "accurate limit factor".

Since the zero-sequence current transformer usually passes through three live wires, the internal space of the zero-sequence current is relatively large under the same primary current. "Inner hole diameter" is an important indicator of zero-sequence current transformers. Generally, it should be noted when ordering.

There are two types of zero-sequence current transformers: integral type and open type. Lets take a look at how the zero-sequence current transformer is installed?

1. The integral zero-sequence current transformer should be installed before laying the cable, and the cable should be installed through the transformer.

2. The installation of the open-type transformer can be carried out at any time, the specific installation method is as follows:

(1) Remove the connecting clamps of the transformers "K1" and "K2".

(2) Loosen and remove the two hexagon socket bolts on the top of the transformer, the transformer is divided into two parts.

(3) Put the transformer on the cable, wipe the two contact surfaces clean, apply a layer of anti-rust oil, align the two parts of the transformer, and screw on the hexagon socket bolts. The two parts of the transformer should be aligned to avoid affecting performance.

(4) Fix the connecting piece on "K1" and "K2".

(5) The upper and lower parts of the same open-type transformer cannot be interchanged with other transformers.