Medium-voltage instrument transformers
Bar Primary Bushing Summary Current Transformer
TZLMA-1-1
The TZLMA-1-1 current instrument transformer is intended for to be used as a power source to supply protection relays circuits which protect the cores of a three-phase cable from earth connection, by transforming the zero components arising during the earth connection.
The transformer is intended for mounting into the KRZ power distribution system designed for up to 0,66 kV. The transformer meets the requirements of GOST 12.2.007.0-75 standard.
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Description
The TZLMA-1-1 current instrument transformer is intended for to be used as a power source to supply protection relays circuits which protect the cores of a three-phase cable from earth connection, by transforming the zero components arising during the earth connection.
The transformer is intended for mounting into the KRZ power distribution system designed for up to 0,66 kV. The transformer meets the requirements of GOST 12.2.007.0-75 standard.
The transformer features the “U” climatic execution, corresponds to the location 2 category to GOST 15150, is installed by slipping over a cable, and is intended for to be operated under the following conditions:
- installation altitude up to 1000 m above sea level, at maximum
- highest ambient air temperature during operation, while considering the heating effects in the inside of the KRZ: +55 °С
- lowest temperature of ambient air during operation: -45 °С
- air relative humidity: 100 % at 25 °С
- air pressure in accordance with the GOST 15543.1 standards
- operating environment without explosion hazards, not containing dust, without chemically active gases and vapours that could impair the surface layers of metal and insulation (type II atmosphere as per GOST 15150)
- transformer operation allowed in any position at the installation area
- the transformer insulation consists of a plastic sheath, with the “U” heat resistance to GOST 8865, made from thermoplastic material
- the transformer conforms to the M6 group of operating conditions to GOST 17516.1
- seismic resistance to up to No. 8 earthquake intensity degree as per MSK-64, at installation altitude up to 70 m above zero level
The warranty period is one year from placing the transformer into service, however up to three years since the moment of its dispatch from the manufacturer´s plant.
Note: * the sensitivity value applies to relay windings connected in parallel, and the resistance of connection wires of 1 Ω, at maximum.
The secondary winding outlets are labelled as „I1“ and I2“.
The transformer base plate contains two Ø 11 mm openings to attach the transformer at the installation place.
ATTENTION! MEASURES ARE TO BE TAKEN FOR THE TZLMA-1-1 TRANSFORMER IN OPERATION TO PREVENT THE OPENING OF ITS SECONDARY WINDING OUTLETS.
If the operation of the transformer becomes no longer to be necessary, its secondary winding has to be short circuited.
The earthing variant of the secondary winding is determined by the user, depending on how the transformer secondary side is connected. The metallic cover and the cable armour have always to be earthed.
Contour dimensions, installation, connecting dimensions and weight of the TZLMA-1-1 transformer.
Parameters
- Highest voltage for equipment: 0,66 kV
- Power frequency test voltage: 3 kV
- Lightning impulse test voltage: 25 A
- Nominal primary current: 1 A
- Nominal secondary current: 50 Hz
- Weight: 3,1 kg
- Thermal insulation class: E
- Operation conditions: operating temperature from -45°C to +55°C
- Standard: GOST 15150, GOST 15543.1
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