The current carrying capacity of a conductor is determined by its internal resistance to the flow of current, which is known as capacitance. The higher the capacitance, the lower the current carrying capacity of the conductor. The electrical conductivity of a conductor, which is also known as resistance to electric current, affects the capacity rating of a conductor.
Capacitance is affected by ambient temperature, air pressure, and air volume. The greater the difference between these three factors, the greater the effect on the capacitance. A current carrying capacity of one hundred thousand volts per inch would be affected by variations in temperature from twenty degrees to thirty degrees Fahrenheit and from ten to sixty degrees Fahrenheit. Likewise, a gauge that reads nine hundred thousand volts per inch at fifteen degrees Fahrenheit would be affected by variations in air pressure.
The short circuit strength is the maximum current carrying capacity of a busbar, which is usually expressed as a percentage of maximum electrical current. This value is affected by a variety of environmental conditions including ambient temperature rise, atmospheric pressure, and humidity. When busbars are placed in temperatures that are consistently high or low, the current carrying capacity of individual conductor bars is different from one another. Short circuits weaken or increase the strength of individual conductors depending on the conditions. A ten degree drop in temperature increases the short circuit strength of all busbars placed in the same room for an hour.
To calculate current carrying capacity of busbars, it is important to determine the inductor color code, which is typically printed on the metal frame of each individual busbar. Inductor color code values are printed in letters of the alphabet. Following the letter code, the letter indicates that conductor is to be connected with what amount of current. Following the color code, the next numbers indicate the voltage that is applied to the conductor, then the next number indicates the resistance value of that particular conductor.
To calculate current carrying capacity of busbars in outdoor weather, one must determine the cold temperature and the hot temperature. After determining these two temperatures, one can determine the air temperature outside and the cold air temperature inside the area of application. If the air temperature is cold, the electrical resistance value of the busbar will be lower than that of an air temperature that is high. Conversely, a busbar placed in a hot area will have higher resistance than one placed in an area where the air temperature is cool. To calculate current carrying capacity of busbars in indoor weather, one must determine the relative humidity. Relative humidity can be determined by using a hygrometer to measure the moisture content in the air.
In addition to considering the variations in temperature rise along with the changes in air temperature, it is important to consider changes in relative humidity because power losses caused by these temperature rise may also affect the operation of a bus duct system. Power losses are especially problematic in hot areas where electricity use is widespread. The calculation of current carrying capacity of busbars must take into account any changes in the temperature rise in the interior of the area of installation because of insulation heating losses. In the case of insulating materials such as fiberboard, any changes in the room’s temperature will also affect the thermal conductivity of that particular room. Any insulation heating losses must be accounted for in the current carrying capacity of busbars calculations.
Current carrying capacities of busbars must be calculated using specific, current design tools. These tools are available from suppliers specializing in bus duct construction equipment. To calculate current carrying capacity of a bus, a current design tool is used that identifies the distance between the center of a conductor in a conductor box and its termination on the inside of a bus. The distance from the center to the termination should be six inches on each end and one inch inside the box. These measurements are referred to as conductor box end dimensions.
Using the formula derived from equation (2), we can calculate the current carrying capacity of a busbar as follows. Compute the voltage across the terminals by multiplying the voltage by the ampere-hours per minute specified in the last step of the calculation. Multiply the amperes per minute by the terminal’s dead time, or the time the busbar has been in operation for, to arrive at the ampere-hours per minute of actual current consumption by the bus. If the ampere-hours per minute is smaller than the terminal’s dead time, the current consumption per minute is greater than the terminal’s dead time.
It is necessary, therefore, to adjust the specifications of the AC voltage and amperes per minute needed to reach the specifications of the AC wihner busbar system. To achieve this, the current consumption needs to be measured with the equipment itself in operation. This will allow the designer to compensate for the loss of efficiency associated with the design of a bus wihner electrical system. It is also important to consider the load requirements for a power supply that is being considered. The DC load should include the DC to operate all of the equipment in a factory, as well as the machines that are being run in the plant. The bus load is a lower number than the total amperes used in each circuit.
There is an effective way to calculate the current carrying capacity of a busbar using a discrete model. By considering the potential losses associated with all of the potential paths that a current can take through any given circuit, it is possible to calculate the amount of current losses. The resulting value is then compared to the maximum allowable current carrying capacity of the circuit breaker. In order to convert this value into a usable rating, it is necessary to use one of the many formulas that are based on this concept.
An important consideration in the calculation of a busker’s DC to AC power ratio is the potential gain from switching different AC power sources. For example, if two different alternating current sources are selected, there will be a greater DC current carried by the busbar. Therefore, it is necessary to compensate for the potential losses associated with AC power switches. A way to overcome the potential losses involved in switching AC power sources is to build a substation that is capable of switching both AC power sources. This will allow the Busch Company to provide AC power to the entire distribution system while only maintaining a minimum level of DC current flowing through the busbars.