soft starter

Difference between DOL, Star Delta, VFD and Soft starter

DOL-Direct on line Starter: here the starting current will be 6 times of full load current. A bimetallic thermal overload relay provides protection against the over load. There will be no reduction of starting torque during starting. Star Delta Starter: In order to limit the starting current of motors this method is followed. Initially motor…

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How to calculate cable size for LT Motors

What is the difference between LT and HT Motors? Well, as the word LT (Low Tension i.e. Low Voltage) and HT (High Tension i.e. High Voltage) or low torque and high torque respectively describe the whole story itself. its also depends on the availability of supply voltage, i.e. in USA and EU, LT Motors ranges…

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battery

Battery charging calculation

How to Calculate the charging Time and Charging current for battery Charging? Easy Battery Charging Time and battery Charging Current Formula for Batteries. ( with Example of 100Ah Battery). Battery Charging Current and Battery Charging Time formula Here is the formula of Charging Time of a Lead acid battery. Charging Time of battery = Battery…

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numerical relay

Why Numerical Relay over Electromechanical Relay

Advantages of Numerical relays 1.      Compact Size Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays. It uses a flag system for the indication purpose whether the relay has been activated or not. While numerical relay is in compact size and use indication on LCD…

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relay

Circuit Breaker Tripping Schemes

Circuit Breaker Tripping Schemes Basically two types of tripping schemes which are given below:- Relay with make type contact. Relay with break type contact.   1) Relay with make type contact: In this scheme, the relays are connected in the stare, and contacts of each relay are connected in parallel and this parallel unit of…

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types of insulator

Causes of failure of insulator

The causes of the failure of insulator are :-   Cracking of insulator: The main cause of cracking is due the stress produced in the porcelain due to unequal expansion and construction produced in cement, steel and porcelain caused by seasonal heat cold, dryness, and dampness or by heating of the insulator. To avoid such…

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armature winding

Magnetic Saturation

If we increase the mmf of a magnet, the flux density inside the core to of the is also increased. Now we can ask a question, whether there is any limitation of increasing flux density in the core of magnet with increasing applied mmf. The answer is yes. There is a limit beyond which there…

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