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What is the difference between diffrencial relay and a distance relay?
They're completely different, used for different applications (usually). A distance relay uses both current and voltage. A differential relay uses only current. A differential relay usually has harmonic restraint capability, while distance relays ideally track system frequency. Differential relays require fast operation, while distance relays may not be required to operate as quickly. Distance relays have more issues with operating for out of zone problems than differential relays. There are many more, but this gives an idea.
How does the standby earth fault scheme work?
Restricted earth fault protection is used to protect a specific zone, and should not trip for a fault outside of that zone (usually limited to a transformer, and possibly extending to lowside, highside, and tertiary breakers). Stand by earth fault protection is a term I am not very familiar with, but I believe this would be protection that is meant for a specific zone as backup, and can operate for faults outside of this zone. An example might be a highside time overcurrent relay set looking into a transformer, where the transformer is protected by a differential (primary protection), and there is a lowside feeder with relays (primary protection). The highside overcurrent acts as a backup (secondary protection) for the transformer and the feeder, and is delayed due to the nature of a time overcurrent relay.
What is an Unrestricted Earth Fault?
I'm guessing this is in reference to a restricted earth fault, and you want to know what the opposite is? Restricted earth fault protection is designed to operate for earth faults within a specific zone. Unrestricted protection will operate for faults "anywhere", as long as the pickup can be satisfied. For example, REF (restricted earth fault) transformer protection looks for a small amount of neutral current, and if this exists, and the relay identifies this current as being within the zone of protection, the relay will trip. If it were unrestricted, the small amount of neutral current alone would be enough to cause a trip.
Where is construction joints in column?
To avoid reinforcement lapping zone and spliceing zone
Describe a zone in a hydronic heating system?
describe what is a zone in ahydronic heating system
What is a exchange zone?
exchange a zone
What is an exchange zone in track and field?
exchange a zone
What are the minimum markings on a day drop zone?
Code Letters.
How can we make the distance relay to operate in 3 zones?
as distance relay is an impedance relay & measures impedance interms of current & voltage. first zone : 85% of the selected ist portion's impedance interms of resistance & reactance. normally we use 85% to 90% of ist portion to avoid any human & other CT & PT's instruments errors. secound zone: selected zone ist + 50% of the secound selected portions. Third ZOne: selected zone ist + zone 2nd + 20% of the thrid selected portions. Distance relay is CT & PT operated relay & give us exact location of the fault after measuring the level of the fault current & voltage.
Why is baton exchange important in track an field?
The baton is used in relay races; 4x100m, 4x400m, etc, exchange is very important because if dropped, that team is automatically disqualified. Also if a team member steps out of their lines during the exchange they are disqualified. Futherore mastering a quick exchange is key to a faster time.
The conducting zone of the respiratory system does not?
exchange gases with the blood
What is acceleration zone in track and field?
The exchange zone on a 400 meter track is 20 meters long. For races involving 200 meter legs or less, a 10 meter acceleration zone may be marked on the track and used by the runner receiving the baton to accelerate to match speed with the incoming runner. With or without an acceleration zone, the baton must still be exchanged within the official 20 meter zone.
When DNS server exchange information among themselves it is known as?
Zone transfers
What is full form of ZTE?
Zero Time Exchange Zone Telecommunications Engineer
What is directional protection relay and how is it works?
Directionalized relays are relays that use a polarizing circuit to determine which "direction" (in the zone of protection, or out of the zone protection) a fault is. There are many different types and different polarizing methods - ground polarizing, voltage polarizing, zero sequence voltage polarizing, negative sequence polarizing, etc. The basic operation of this relay is just like any nondirectional relay, but with an added torque control - the directionalizing element. This element allows the relay to operate when it is satisfied that the fault is within the zone of protection (ie not behind where the relay is looking).
What are the markings on an Ice Hockey rink?
The markings are: Blue face off dots and red circles in each end zone, two blue face off dots outside each end zone, two blue lines separating the neutral zone from the two end zones. A red centre face off circle and dot at centre ice. A red centre line which separates the ice surface into two halves's. A red goal line in each end zone. Multiple names and markings for advertising, team name, arena name etc are also included on the ice surface in most arenas.
Where can I find the money exchange rate for China?
http://wwp.greenwichmeantime.com/time-zone/Asia/china/currency-china/index.htm offers a money exchange calculator where you plug in how much you want to exchange.
