Medium Voltage CT & PT
The task of instrument transformers is to transform high currents and voltages proportionally and in-phase into small current or voltage values for measuring or protection purposes. Current transformers (CTs) may have multiple secondary windings with cores that are magnetically independent and can have varied characteristics. They can be configured with different types of cores for diverse accuracy needs, such as one for precise measurements and another for general protection purposes. Voltage transformers (VTs) typically have a single magnetic core and one secondary winding. Some VTs, especially those designed for single-phase systems, may also include an extra winding known as a residual voltage winding, which is used to detect earth faults.

Protective and Measuring Transformers for Medium-Voltage Equipment
Overview of MV CT and PT/VT transformer

LZZBJ9-10C1 Indoor MV Current Transformer
10kV current transformer, most popular item

LZZBJ9-12/150b/2 MV Current Transformer
335*155*220mm

LZZBJ9-12/150b/4 MV Current Transformer
460*150*250mm

LZZBW-10 Current Transformer
Outdoor type

LZZBJ9-10C2-10 MV Current Transformer
320*175*225mm

LZZJB6-10Q Current Transformer
290*150*216mm

LZZBJ9-10C MV CT
310*155*220mm

10P10 10P15 Current Transformer LZZBJ9-10A
335*155*220mm

LZZBJ9-12/175b/2
300*175*250mm

Multi-ratio MV Current Transformer LZZBJ9-12-175B-4
460*175*250mm

LZZB9-24-180B-2
351*180*306mm

20KV Current Transformer (LZZB9-24-180B-4)
471*180*306mm

LZZW10Q

LZZBJ9-12/185B/4
460*185*250mm

Indoor 10KV Current Transformer (LZZBJ9-12/185B/2)
355*185*250mm

35KV Current Transformer LZZBJ9-35-2
490*300*440mm 2 core

Mini type 10KV Current Transformer LZZBJ9-10M
290*150*200mm

LZZBJ9-35-3
490*300*440mm 3 core

LZZBW-15 current transformer
280*280*341mm, outdoor type

JDZX11-20
20kV indoor type

JDZ9-3/6/10
356*160*268mm

JDZX10-10A
330*160*236mm

JDZ10-3/6/10
315*150*214mm

JDZ10-10B
350*180*254mm

JDZX10-3-6-10
315*150*214mm

JDZX9-3/6/10
360*160*260mm

JDZ11-20
20kV indoor type

LZZW35
Outdoor type

JDZX9-35
410*240*488mm

JDZXW35
Outdoor type

JDZW9-35Q(G)
Outdoor type

JDZ10-3/6/10A
330*160*232mm

JDZ9-35
490*300*515mm

JDZ10-11
315*150*214mm

JDZ10-11A
330*160*232mm

JDZ10-11B
350*180*254mm

JDZX10-11
315*150*214mm

JDZX10-11A
330*160*236mm

JDZX9-11
360*160*260mm

JDZ9-11
356*160*268mm

JDZXW-15 voltage transformer
330*240*508mm, outdoor type

JDZ11-15
Current Transformer
Operating voltage Um: | 12/24/40.5kV |
Rated short-duration power-frequency withstand voltage Ud: | 42/65/95kV |
Rated lightning impulse withstand voltage Up: | 75/125/185kV |
Rated frequency: | 50/60Hz |
Rated primary current IPN: | 5A to 4000A |
Multi-ratio | 2x20 to 2x600 |
Secondary current ISN: | 1/5A |
Rated short time thermal current Ith: | 80kA or 100xIPN |
Rated dynamic current Idyn: | 120kA or 2.5xIth |
Core: | |
Protection (Factor) | 5P10, 5P15, 5P20, 10P10, 10P15, 10P20 |
Power Capacity | 10VA/15VA/20VA/30VA |
Measuring (Accuracy) | 0.2/0.2S/0.5/0.5S/1/3 |
Power Capacity | 10VA/15VA/20VA/30VA |
For example: Measuring only model 600A/5A, 0.2S, 10VA or multi-ratio 2x500A/5A, 0.2/0.5 10/15VA
Measuring with protection model: 600A/5A 0.2/10P10 10/15VA
Voltage Transformer
Operating voltage Um: | 3.6/7.2/12/40.5kV |
Rated short-duration power-frequency withstand voltage Ud: | 25/32/42/95kV |
Rated lightning impulse withstand voltage Up: | 40/60/75/200kV |
Rated frequency: | 50/60Hz |
Rated thermal limiting output of the residual voltage winding: | 230VA/4A |
Rated primary voltage maximum VPN: | 3kV, 6kV, 10kV, 40.5kV, 3/√3 V, 6/√3 V, 10/√3 V,40.5/√3 V |
Secondary voltage USN: | 100V, 220V, 100/√3 V, 220/√3 V |
Thermal limiting output Sth: | 200VA, 300VA, 400VA, 500VA, 600VA, 800VA, 1000VA |
Auxiliary residual voltage winding | Without or 100/3V, 110V/3V, 120/3V |
Rated output of the measuring winding | Class 0.2/0.5/1/3/5 |
Rated output of the protection winding | 3P or 6P |
Rated output of the power capacity | 10VA, 15VA,20VA, 30VA, 50VA, 60VA, 100VA,150VA, 200VA etc. |
For example: JDZ10-10A, 10/0.1KV, 100V, 0.2/30VA, Dual output voltage: JDZ10-10A, 10/0.1KV, 100/100V 0.2/0.5 10/15VA
JDZ10-10A 10/√3 / 100/√3 /100/3V 0.5/3P 15/20VA