The excitation current is the main cause of the error of the current transformer, so reducing the excitation current can reduce the error
(1) The core is made of materials with high permeability, because the magnetic properties of the core not only affect the ratio difference and angular difference, but also affect the saturation multiple.
(2) Increase the cross-section of the iron core and shorten the length of the magnetic circuit; Increase the number of turns of the coil. Increasing or decreasing the core section or coil amperage will increase and decrease the saturation factor accordingly. The effect on the saturation factor must be taken into account when increasing the core section or coil ampoule to improve the ratio and angular difference.
(3) Limit the impact of secondary loads. In the field, the method of increasing the effective cross-sectional area of the connecting line is generally adopted, such as using a cable with a large cross-sectional area, or multi-core parallel connection to reduce the impedance value of the secondary load. It is also possible to use two current transformers of the same model and the same proportion in series, so that the load of each current transformer becomes half of the whole load.
(4) Appropriately increase the transformation ratio of current transformer. When running on site, a transformer with a large variable ratio is selected.
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1. The influence of the environment on the reliability of the relay: the average time between failures of the relay is the highest under GB and SF, reaching 820,000h, while in the NU environment, it is only 60,000h.
2. The influence of quality grade on the reliability of relays: when the relay of A1 quality grade is selected, the flat ...
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Siemens APT LA39 series button FAQ
1. What are the installation methods of LA39-A/B/C button?
There are five types in total: the Z1 diagonal screw unit, the Z2 straight screw unit, the Z3 nut device with fastening screws, the Z4 nut device without fastening screws, and the Z5 quick and convenient one-handed device
2. LA39 series products can be used ...
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TL series police lights frequently asked questions
1. How many light sources are there for the TL-70 police light?
There are 3 types, namely LED, incandescent and xenon.
2. What are the colors of the TL-70 police light?
There are 5 types, which are red, yellow, green, blue, and white.
3. What are the types of TL-70 police lights?
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Siemens APT Relays - Maintenance Methods for Solid State Relays
1. The influence of the ambient temperature
The load capacity of the solid state relay is greatly affected by the ambient temperature and its own temperature rise, during the use of the device, it should be ensured that it has good heat dissipation conditions, the rated working current of more than 10A products should be equipped with radiators, and the products above 100A should be dissipated.
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Siemens APT limit switches – what are the limits used for?
daily life
There are many applications of travel switches, and it is found in many electrical appliances. So what does such a simple switch do? It mainly plays the role of chain protection. The most common example is its use in washing machines and tape recorders (VCRs). ...
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Siemens APT Relays – What should I pay attention to when selecting relays?
1. When selecting a relay, it is necessary to understand the load and type of its contact, because the contact method of the relay of the same model is different, with multiple groups of contacts and single group contacts. When selecting a relay, you can choose the type of contact.
2. And in the peach ...
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Siemens APT current transformer - working principle and characteristics of current transformer
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The principle of current transformer is based on the principle of electromagnetic induction. A current transformer is composed of a closed core and windings. It has a small number of turns on the primary side winding, stringed in the line where the current needs to be measured, so it often has the full current of the line ...
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Siemens APT relay - the main structural features of high and low voltage relays
1. Electromagnet: The electromagnet of high and low voltage relay is usually composed of two parts: coil and core. When the high and low voltage relay inputs the electrical signal, the electromagnet coil will generate electromagnetic force, drive the iron core, and realize the on/off control of the relay.
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What are the main problems with Siemens APT Relays – Solid State Relays?
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Siemens APT current transformer – precautions for current transformers
1. Before the installation of the open current transformer, it must be connected to the meter (or other measuring devices) for the second time to ensure that the transformer is not open for the second time;
2. Place all the open current transformers connected to the secondary line on the site and wait for installation;
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Siemens APT - LW39 series 10,000 revolutions FAQ
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At present, there are four forms: 10A, 16A, 25A, and 63A
2. What are the positioning angles of the universal transfer switch?
At present, it is divided into four angles: 30°, 45°, 60° and 90°
3. There is no customer's ...
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Siemens APT helps Tianjin's advanced manufacturing industry
Tianjin is a typical industrial city. Due to the steady progress of "three districts and one base", the advanced manufacturing industry has developed rapidly in recent years. Siemens APT brought a variety of low-voltage control products to the 14th China (Tianjin) International Industry Fair held from March 15-18. Siemens APT has launched the PB1...
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3、 ...
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Siemens APT current transformer - precautions for the use of current transformer
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2. Estimation ...
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