LX3-2,LX3-4,LX3-7(LJ),LXM series zero sequence current transformerDetailed product description：

I. Overview
LX3-2, LX3-4, and LX3-7 are equivalent to LJ zero sequence current transformers used in conjunction with relay protection devices or signal devices when generating zero sequence grounding currents in the system, to activate device components and achieve protection and monitoring.

2、 Model meaning

3、 Categories and main data of LX3-2, LX3-4, LX3-7 (LJ), LXM series zero sequence current transformers
(1) The new LX3-2, LX3-4, and LX3-7 are thick cable type zero sequence transformers, which are fully sealed with resin casting, resulting in better insulation performance, more beautiful appearance, and easier installation. This transformer is used in conjunction with DD11/60 type relays, with a secondary load of 10 Ω.

Figure 1: Outline Dimensional Diagram of Series Transformers

Table 1 Dimensions of LX Series Transformers (Part 1)

new model	old model	Inside d	External D	Thick M	Hole center main r	mounting hole spacing	zero-sequence current	secondary current
LX3-2	LJ-2	one hundred and ten	two hundred and thirty	one hundred and ten	one hundred and forty	one hundred and thirty	1-3A	0.06A
LX3-4	LJ-4	one hundred and forty	two hundred and eighty-five	one hundred and ten	one hundred and sixty-eight	one hundred and thirty	1-3A	0.06A
LX3-7	LJ-7	one hundred and eighty-five	three hundred and ten	one hundred and ten	one hundred and eighty	one hundred and thirty	1-8A	0.06A

(2) The external insulation of LJ-2, LJ-4, and LJ-7 cable type zero sequence transformers of the same product is wrapped with insulation tape.

Figure 2 External dimensions of LJ series transformers

Table 2 Dimensions of LJ Series Transformers

model	A	H	Internal diameter d	Outer diameter D	Weight (kg)
LJ-2	one hundred and forty-five	two hundred and ninety-five	one hundred and ten	two hundred and thirty	twenty-one
LJ-4	two hundred and twenty	three hundred and fifty-five	one hundred and forty	two hundred and eighty-five	twenty-nine
LJ-7	two hundred and forty	three hundred and eighty-five	one hundred and eighty-five	three hundred and ten	thirty-one

(3) LX3- φ 75, LX3- φ 100, and LX3- φ 125 are thin cable type zero sequence transformers.
The transformer adopts resin casting for full sealing, which has the characteristics of good insulation performance, beautiful appearance, and easy installation. This type of transformer is used in conjunction with DD11/0.2 type relays, with a primary zero sequence current of 10A, a secondary current of 0.2A, and a secondary load of 10 Ω.

Figure 3 LX series transformer external dimensions diagram three

Table 3 Dimensions of LX Series Transformers (III)

new model	old model	Inside d	External D	Thick M	mounting hole spacing	Hole center height r
LX3-Φ75	LJ-Φ75	seventy-five	one hundred and thirty-five	fifty-five	one hundred and ten	eighty-five
LX3-Φ100	LJ-Φ100	one hundred	one hundred and sixty	fifty-five	one hundred and ten	ninety-five
LX3-Φ125	LJ-Φ125	one hundred and twenty-five	one hundred and ninety-five	sixty-six	one hundred and ten	one hundred and twenty-five

(4) LXK - Φ 100, LXK - Φ 120 open-ended cable type zero sequence transformer.
The iron core of the zero sequence transformer is divided into two sides that can be folded, making it easy to install when cables have already been laid. The two sides of the transformer are resin cast, which has the characteristics of good insulation performance, beautiful appearance, and easy installation. This transformer is used in conjunction with DD11/60 type relays, with a primary zero sequence current of 3-5A, a secondary current of 0.06A, and a secondary load of 10 Ω.

Figure 4 External dimensions of LXK series transformers

Table 4: Dimensions of LXK Series Transformers

appearance	LXK Φ100	LXK Φ120
Internal Φ	one hundred	one hundred and twenty
External D	one hundred and ninety-five	two hundred and fifty
H	two hundred and twenty	two hundred and seventy-five
Y	one hundred and twenty-three	one hundred and fifty
M	eighty-five	one hundred

(5) LXM-1, LXM-2, LXM-3 busbar zero sequence transformers. This type of transformer is used in conjunction with DD11/60 type relays, with a primary zero sequence current of 2.4A, a secondary current of 0.06A, and a secondary load of 10 Ω.

Figure 5 External dimensions of LXM series transformers

new model	old model	Copper quantity	rated current	Thermal stability current	dynamic stable current
LXM-1	LXM-1	1 piece	1750A	24kV	60kV
LXM-2	LXM-2	2 pieces and	3000A	48kV	120kV
LXM-3	LXM-3	3 pieces and	4000A	72kV	180kV

Please specify if there are any differences in zero sequence current and relay parameters among the above models of transformers.
(6) Neutral point grounded cable type zero sequence current transformer.
1) At present, the types of high current grounding and low current grounding for neutral points in China's 6 and 10kV power grids are gradually increasing. Therefore, the specifications of their zero sequence current transformers are as follows:
(a) 150/5A,200/5A， Load 0.6 Ω.
(b) 40/0.5A，75/0.5A，100/0.5A， Load 13 Ω. In addition, other specifications of zero sequence current transformers can be designed and manufactured according to user requirements.
2) Model meaning

3) The main technical data is shown in Table 6.
Table 6 Main Technical Data

model	inner diameter d	Outer diameter D	Thickness M	hole center High Y	mounting hole spacing	Current once	Current once	Secondary load
LXZ-φ100	one hundred and ten	two hundred and thirty	one hundred and ten	one hundred and forty	one hundred and thirty	150A	5A	0.6Ω
LXZ-φ145	one hundred and forty-five	two hundred and eighty-five	one hundred and ten	one hundred and sixty-eight	one hundred and thirty	150A	5A	0.6Ω
LXZ-φ150	one hundred and fifty	two hundred and sixty	seventy	one hundred and sixty	one hundred and thirty	150A	5A	0.6Ω
LXZ-φ185	one hundred and eighty-five	three hundred and ten	one hundred and ten	one hundred and eighty	one hundred and thirty	150A	5A	0.6Ω
LXZ-φ200	two hundred	three hundred and twenty	seventy	one hundred and ninety	one hundred and thirty	150A	5A	0.6Ω

Figure 6 External dimensions of LXZ series transformers

LX3-2, LX3-4, LX3-7 are equivalent to LJ zero sequence current transformers