How do you read TCC?

TCC of a Transformer: A circuit breaker should ideally be to the right side and above of a transformer inrush curve. This indicates that a circuit breaker will not trip under inrush current conditions. If the breaker curve is to the left of an inrush curve then it would indicate nuisance tripping.

How do you plot time curve current?

Draw a vertical line to the point where it intersects the curve. Then draw a horizontal line to the left side of the graph and find the time to trip. For example, in this illustration a circuit breaker will trip when current remains at 6 amps for 0.6 seconds.

How do you plot TCC?

Plotting a TCC Curve from a One-Line

1. Select only one item by clicking on the item.
2. Select more than one item, by holding down the CTRL key and select items individually, clicking the items that you would like to plot.
3. Drag the mouse to form a box around the items you would like to plot.

What scale are time current curves illustrated?

Current is shown on the horizontal axis using a logarithmic scale and is plotted as amps X 10X. Time is shown on the vertical axis using a logarithmic scale and is plotted in seconds X10X. The light blue curve is a switchgear feeder circuit breaker curve.

What is a TCC curve?

A time current curve (TCC) plots the interrupting time of an overcurrent device based on a given current level. These curves are provided by the manufacturers of electrical overcurrent interrupting devices such as fuses and circuit breakers.

What are the various time current characteristics available for an overcurrent relay?

1) Operates in a definite time when current exceeds its Pick-up value. 2) Its operation criterion is only current magnitude. 3) Operating time is constant. 4) There is no intentional time delay.

How do you read tripping characteristics?

The Trip Curve

1. The X axis represents a multiple of the operating current of the circuit breaker.
2. The Y axis represents the tripping time. A logarithmic scale is used in order to show times from . 001 seconds up to 10,000 seconds (2.77 hours) at multiples of the operating current.

What is a damage curve?

Damage curves are defined in the IEEE standards in per unit on the nominal base rating (kVA) of the transformer, and are not adjusted with changes to the core, winding material or method of cooling.

What is a time current curve?

What is tripping characteristics of MCB?

Types of MCB based on Tripping Characteristics

What is time current curve?

What is a time-current curve?

How fast a breaker will trip. Time-current curves are used to show how fast a breaker will trip at any magnitude of current. The following illustration shows how a time-current curve works. The figures along the bottom (horizontal axis) represent current in amperes. The figures along the left side (vertical axis) represent time in seconds.

What are timetime current characteristic curves (TCCS)?

Time Current Characteristic Curves play a significant role in achieving proper protection coordination among the electrical safety devices. Learn more as we cover basics of power system protection, TCCs for the solid state and thermal magnetic trip, importance, procedure and rules of selective coordination here.

What does the bottom part of the time current curve show?

The bottom part of the time-current curve shows the performance of the instantaneous trip component (short circuit) of the circuit breaker. The maximum clearing time (time it takes for breakers to completely open) decreases as current increases.

What is the significance of time current curves for power Protection coordination?

Studies are required for protecting the crucial power system equipment. Selective and protection coordination is done with the help of Time Current Curves (TCCs). This article discusses the significance of power protection coordination and how time current cufrves are used for the purpose of selective coordination.

https://www.youtube.com/watch?v=8ZjqsoiG-nc