Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

Compared to traditional oil-filled transformers, dry-type transformers offer several advantages. Key benefits of dry-type transformers include:Safety: Dry-type transformers are considered safer as they lack flammable liquid insulation (such as oil). They eliminate risks associated with oil leaks, spills, and related fire hazards. This makes them suitable for indoor installations, especially in areas where fire safety is a priority, such as commercial buildings, hospitals, and schools.Environment

Accurate time relay measurement requires systematic steps to ensure reliable results. Before measurement, confirm the relay model, rated parameters, and operating environment, maintaining ambient temperature at 20±5°C and humidity below 85%RH. Prepare a high-precision timer (resolution 0.001s), regulated power supply (±1% fluctuation), standard load (matching contact rating), and digital multimeter.Calibrate the timer and power supply, ensuring equipment error is within ±0.5%. Mount the relay on

Time relays are commonly used industrial control devices. Based on their timing characteristics, they can be classified into three types: on-delay, off-delay, and combined on/off-delay relays. Among these, on-delay time relays are the most widely used and readily available in the market. However, many on-delay relays have a limited number of contacts and only provide timed contacts without instantaneous ones, which poses inconvenience for electrical control circuit designs requiring immediate re

In electrical and electronic engineering, time relays are crucial control components. Operating on electromagnetic or mechanical principles, they delay the closing or opening of contacts within control circuits. This time-delayed action enables circuits to automatically perform specific operations after a set interval. Based on their timing characteristics, time relays are primarily classified into two types: on-delay and off-delay.1. On-Delay Time RelayAn on-delay time relay does not respond im

Common Faults and Troubleshooting:(1) Over time, the adjustable potentiometer used to set the delay time may suffer wear of the carbon film or accumulate dust, leading to inaccurate timing. To address this, apply a small amount of electrical contact cleaner around the potentiometer shaft, then rotate the shaft back and forth to clean the internal contacts. If the potentiometer is severely worn, replace it promptly.(2) Damage or aging of transistors can alter the parameters of the timing circuit,

As an electrical component capable of achieving time-delay control, time relays are widely used in various circuit systems. Correctly understanding and mastering the wiring methods of time relays is essential for electrical engineers and electronics enthusiasts. This article presents detailed wiring diagrams to explain the applications and wiring methods of two common types—on-delay and off-delay time relays—in practical circuits.1. On-Delay Time Relay1. Wiring Diagram ExplanationA typical on-de

I. Allowable TemperatureWhen a transformer is in operation, its windings and iron core generate copper loss and iron loss. These losses are converted into heat energy, causing the temperature of the transformer's iron core and windings to rise. If the temperature exceeds the allowable value for a long time, the insulation will gradually lose its mechanical elasticity and age.The temperature of each part of the transformer during operation is different: the winding temperature is the highest, fol

1. Definition of Condition-Based MaintenanceCondition-based maintenance refers to a maintenance method where decisions on whether and how to perform maintenance are determined based on the real-time operating status and health condition of equipment. It has no fixed maintenance methods or schedules. The prerequisite for condition-based maintenance is the establishment of equipment parameters and the comprehensive analysis of various operational information of the equipment, so as to make reasona

Traction Rectifier TransformersRated capacity: 800 to 4400 kVA; Voltage class: 10 kV and 35 kV; Rectifier pulse number: 12-pulse and 24-pulse. Compared with 12-pulse rectifier circuits, 24-pulse rectifier circuits can reduce the harmonic pollution of the power grid by 50%, and no filtering equipment is needed at this location. It is suitable for power supply systems of urban subways and rail transit.Excitation Rectifier TransformersRated capacity: 315 to 3000 × 3 kVA; Voltage class: 10 kV, 13.8

Operating Conditions in National Standard GB 6450-1986Ambient temperature: Maximum ambient temperature: +40°C Daily average maximum temperature: +30°C Annual average maximum temperature: +20°C Minimum temperature: -30°C (outdoor); -5°C (indoor) Horizontal axis: Product load; Vertical axis: Average coil temperature rise in Kelvin (note: not in Celsius).For Class H insulation products, the long-term temperature resistance of insulation materials is stipulated by the state as 180°C. However, the in