What is busbar configuration?

What is busbar configuration?

The busbar arrangement uses bus coupler which connects the isolating switches and circuit breaker to the busbar. The bus coupler is also used for transferring the load from one bus to another in case of overloading. The following are the steps of transferring the load from one bus to another.

What are the different types of busbar arrangements used in substations?

Single Bus-Bar Arrangement

• Single Bus Bar.
• Single Bus Bar with Bus Sectionalized.
• Main and Transfer Type.
• Double Bus Bar Double Breaker.
• Sectionalized Type Arrangement.
• One and Half Breaker.
• Ring Arrangement.
• Mesh Arrangement.

How many types of busbar schemes are there?

The types are: 1. Single Bus-Bar Arrangement 2. Single Bus-Bar Arrangement with Bus Sectionalization 3. Main and Transfer Bus Arrangement 4.

Why busbar is used in substation?

A busbar is an electrical junction used for collecting electric power from the incoming feeders and distributes them to the outgoing feeders. The main purpose of a busbar is to carry electricity and distribute it. Busbars are used to make the systems more efficient.

Why bus PT is required?

A PT is an instrument transformer. It is used to convert the bus voltage to a safer lower value for metering and indication . It provides both isolation and scaling.

What is bus bar in substation?

In electric power distribution, a busbar (also bus bar) is a metallic strip or bar, typically housed inside switchgear, panel boards, and busway enclosures for local high current power distribution.

What is the major factor considered when selecting a busbar scheme?

An important factor in selection of bus-bar scheme is the degree of reliability of supply expected during maintenance or faults.

How much current can a busbar carry?

Thumb Rule for Busbar Amp Size Both aluminium and copper have their own ability to withstand currents. A 1 Sq.mm of aluminium busbar can withstand 0.7 Amperes. A 1 Sq.mm of copper busbar can withstand 1.2 Amperes.

Why CT is star connected?

In potential transformer the primary and secondary windings are star connected, because in star configuration, the line voltage is root 3 times of phase voltage, hence the voltage distribution to each winding is reduced or divided by 1.732 times. Due to that the insulation cost on the primary winding comes lesser.

Why is PT secondary earthed?

To prevent the secondary circuits from attaining dangerously high potential to ground, these circuits have to be grounded.

What is bus PT and line PT?

Line pt means to measure incoming line voltage. Thebus pt means measure. The bus needs to be protected under the bus’s voltage. Protection for motor feeders.

How busbar is rated?

The IEEE states a busbar should be rated at the highest amperage passing through any section of the busbar, with a maximum of a 50° C rise in temperature from an ambient temperature of 50° C.

Why is CT secondary earthed?

If the secondary is not connected to a load, then it tries to maintain the counter magnetic field, and voltage levels may skyrocket. Levels can get so high, the air around the CT may start to break down and lose its insulating properties. This is why you should always make sure the secondary side of the CT is shorted.

Why is PT always open?

Due to low voltage regulation, the secondary terminal voltage will remain constant and hence if we keep the PT terminals open, nothing is going to happen as the secondary voltage is low (110 / 1.732 = 63.5V). Mind that the same is not true for CT. CT secondary terminals should never be kept open.

Why is PT connected in parallel?

PT needs to be connected in parallel because we need to measure the voltage.