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Fault/short circuit current is the available current from the source when a short circuit occurs. It is the maximum current the source can provide, defined as an RMS value, usually without any DC offset.
Surge current is the maximum instantaneous current that is drawn by "turning on" or energizing a device such as a motor or transformer.
Surge current will be less than fault current. If you assume a very strong source relative to the device rating, the surge current will be solely dependent upon the device in question (so fault current and surge current have no intrinsic connection). For a transformer, inrush may be 5-7 times the self cooled full load rating. Motors are usually less than this, and depending on the starting technique and configuration can be little (20-50%) over full load rating.
From these definitions, and the above paragraph, it should be clear that if you have a weak source relative to the device, the device may not be able to draw as much current as it would if connected to a stronger system. If this occurs, the voltage will dip.
An example would be a system where the available short circuit power is 600MVA; A 60MVA transformer is connected to this system bus. Energizing this transformer without any sort of controled closing could result in (7) x 60MVA = ~420MVA on inrush. This is relatively close to the available short circuit power (70%), so you can expect the system voltage to dip as a result. If the available short circuit current was around 20,000MVA, energizing such a transformer would not cause any significant system voltage dip.
What else can I help you with?
Which Mainly fault in computer hardware?
Static electricity, power surge, short current caused by dust or other contamination.
What is the surge current limit for a 40 A MCB?
A 40A MCB is a circuit breaker. The surge current limit is protected to 250A 8/s0uS. The limitation capability of a circuit breaker is that characteristic whereby a current less then the prospective fault current is allowed to flow under short circuit conditions.
Why use surge protecting resistor to generator rotor winding?
To limit the fault current used surge protective resistance in generator rotor winding to protect the rotor winding heavy damage.
What is the difference between an electrical surge and a brownout?
A surge is an over voltage and over current situation and a brownout is an under voltage situation.
Different between locked rotor current and starting current?
Locked rotor current is the current drawn by a motor when the rotor is prevented from turning, usually occurring during a fault condition. Starting current, on the other hand, is the initial surge of current required to start the motor and overcome inertia. Locked rotor current is typically higher than starting current.
What you mean surge produce in oil of transformer?
If there is a fault and thus high current flow and thus the substantial heat generation results into boiling effect on oil and gas / bubble formation takes place with in the oil chamber that surge out of the chamber. This is sometimes referred to as surge in oil.
What are the differences between a GFCI and a surge protector, and how do they each protect against electrical hazards?
A Ground Fault Circuit Interrupter (GFCI) protects against electric shock by quickly shutting off power when it detects a ground fault, such as current leakage. A surge protector protects against voltage spikes by diverting excess electricity to the ground. Both devices help prevent electrical hazards, but in different ways.
What is an unintended current closed connection between two points in a circuit called?
Power Surge
What is an unintended high current closed connection between two points in a circuit called?
Power Surge
What is difference between surge absorber and surge suppressor?
There is likely no difference. Neither is accepted terminology for a surge suppressive device (SPD). If these products have been tested by safety organizations such as CSA (Canada) or UL (US) or tested to international surge standards (IEEE, IEC), then they should bare the correct terminology, otherwise, they are not tested to provide protection to equipment during a surge. Surge Absorber acts as a load that utilizes the high current until it exhausts. but the surge suppressor diverts the high current into ground without reaching the sensitive parts of the circuit. Surge absorber degrades faster than a surge suppressor.
What is a surge in voltage or current in an electrical circuit called?
A transient, surge, spike, etc.
Will GFCI prevent surge damage?
No, GFCI (Ground Fault Circuit Interrupter) outlets are designed to protect against electrical shock hazards, not surge damage. For surge protection, you would need to use surge protectors or whole-house surge protection devices.
