0
Why Disconnect switch should be placed before current transformer cabinet?
Wiki User
∙ 13y ago
Usually disconnects are placed around any equipment that you may have to do maintenance on in the future and don't want to have to take larger outages than necessary. If the current transformer is on a substation bus, and you don't want to take an outage to that bus, but would like to take a look at the CT's, you should put disconnects around it to allow such maintenance activities.
Wiki User
∙ 13y ago
Add your answer:
Earn +20 pts
What usually happens at consumer end when the current carrying capacity of transformer is exceeded?
What should happen is that the circuit-breaker should trip to cut off the current before the transformer becomes damaged by overheating.
What component do you remove to isolate the secondary distribution center transformer before connecting the primary power cables?
the electric fusible disconnect EDF switches
What must happen to the electric current in power lines before it can safely enter your home?
step-down transformer
What kind of transformer is used to change the voltage of electric current in transmission lines before it enters houses in a neighborhood?
It's called a 'distribution transformer', as opposed to a 'power transformer' which is used in the transmission and primary-distribution electrical systems.
What is the difference between protective current transformer and metering currrent transformer?
Usually nothing. The only difference is what it is connected to and operates. The leads from the current transformer could power a meter for remote indication or a protective relay to trip the system offline.
What usually happens at consumer end when the current carrying capacity of transformer is exceeded?
What should happen is that the circuit-breaker should trip to cut off the current before the transformer becomes damaged by overheating.
What component do you remove to isolate the secondary distribution center transformer before connecting the primary power cables?
the electric fusible disconnect EDF switches
What are the factors affect the magnitizing inrush current in power transformer?
1- residual flux existing before enegizing the transformer . 2- size of transformer . 3- size of power system. 4- type of magnetic material of the core. 5- the method of energizing the transformer.
What must happen to the electric current in power lines before it can safely enter your home?
step-down transformer
What kind of transformer is used to change the voltage of electric current in transmission lines before it enters houses in a neighborhood?
It's called a 'distribution transformer', as opposed to a 'power transformer' which is used in the transmission and primary-distribution electrical systems.
Do you need to disconnect your television cable before cutting it?
There is no current in TV cable, there is no need to disconect it before cutting. Nothing will happen.
What happens when current travels through the second transformer before entering your home?
The voltage is stepped down to 240VAC from 7200VAC
What is the difference between protective current transformer and metering currrent transformer?
Usually nothing. The only difference is what it is connected to and operates. The leads from the current transformer could power a meter for remote indication or a protective relay to trip the system offline.
What is meant by current chopping?
When low inductive currents, such as magnetiing current of transformer, shunt reactors are interrupted by breaker, there is rapid deionization of contact space and may cause the current to be interrupted before its neutral zero. This phenomena is callad current chopping
Why it is necessary to disconnect the load when change the tap?
when the load is connected to draws some current. while changing the tap of the transformer the tappings related to the winding is changed , so the load current affects the transformer. hence while changing the tap it should be noted thatAnswerThere are two types of tap-changing mechanism -'off-load' and 'on-load'. Off-load tap changers physically disconnect the winding when changing from one tap setting to the next. Accordingly, the circuit is temporarily broken, and dangerous arcing will take place if the transformer is energised. Therefore off-load tap changers require that the transformer is disconnected while the mechanism is operated.On the other hand, 'on-load' tap changers use a mechanism which incorporates a 'make before break' contact arrangement, ensuring that no break is made in the circuit as the mechanism moves from one tap setting to the next, enabling it to operate with the transformer energised and supplying load. On-load tap changers are usually automatically operated, although this feature can be overridden and operated manually.
How do you disconnect ammeter from current transformer?
A CT's secondary winding must never be open circuited as it may provide a shock hazard to the user. The terminals to which an ammeter is connected to a CT is normally provided with a set of links that must be closed, short-circuiting the CT, beforethe ammeter can be removed. The ammeter must the be reinstalled before the shorting links are reopened.
Should you use a transformer to step down the voltage before putting it in an electric coil because it will increase the current?
That does seem like a good idea at first, but it has one really major problem, andit can never be used:It's true, you want a large current in the coil, because that makes for a strongelectromagnet. But the current in an electromagnet must be DC, and transformersonly work with AC.(If the input to a transformer is DC, the output from it is smoke.)AnswerA step-down transformer does not 'step up' current, as the question implies. The secondary current is determined by the load attached to the secondary winding. And, further to the first answer, electromagnets (if that's what the load is) work on both a.c. and d.c.
