How to calculate load for LT panels

Understanding how to calculate load for LT panels is one of the most important aspects of electrical planning in any industrial, commercial, or residential setup. LT panels distribute electrical power to machines, lighting systems, motors, HVAC units, and various auxiliary devices, which means the total connected load must be accurately assessed before designing or selecting the panel. When engineers start the process of how to calculate load for LT panels, they first consider every equipment that will draw power from the LT distribution system. This includes motor loads expressed in HP or kW, lighting loads, heating and cooling equipment, plug loads, and machinery with continuous or intermittent operation. Each of these loads is converted into kVA based on its power factor, because panel sizing is always calculated using the apparent power rather than the real power alone.

While understanding how to calculate load for LT panels, engineers also evaluate how much of the total connected load will actually run at the same time. This is where demand factors come in. Motor loads typically run at 70–80% of their rated capacity, while lighting loads may run at 80–90%. By applying these demand factors, the practical running load becomes clearer and helps avoid oversizing or underestimating the panel requirement. Another essential part of how to calculate load for LT panels is the diversity factor, which accounts for the fact that all loads do not operate simultaneously. For large facilities with multiple motors, pumps, compressors, or production equipment, diversity factor becomes extremely important in determining realistic power consumption.

Once every load is listed, converted into kVA, and adjusted for both demand and diversity, the values are summed to get the total running load. This calculated kVA is then converted into current (Amps) using standard three-phase formulas based on 415V LT supply. Current calculation is crucial because the LT panel’s main breaker, cable size, busbar rating, feeder breakers, and protection devices all depend on the final amperage. When professionals work on how to calculate load for LT panels, they ensure that the resulting amperage is not just accurate for present demand but also practical for future expansions. Most electrical consultants recommend adding a 25–30% safety margin so that the LT panel can support additional machines, increased production load, or future equipment upgrades without major modifications.

Properly understanding how to calculate load for LT panels ensures not only accurate panel sizing but also electrical safety, reduced downtime, improved energy efficiency, and longer lifespan of components. An undersized panel can lead to overloading, overheating, frequent tripping, and equipment failures, while an oversized panel increases unnecessary costs. Therefore, a scientific and structured approach to load assessment is essential. By analyzing connected loads, applying appropriate factors, converting to kVA and Amps, and adding allowance for future scalability, electrical engineers can determine the right LT panel rating for any application. Mastering how to calculate load for LT panels leads to reliable power distribution, stable operations, and long-term electrical performance across industries.

We provide top Industrial Services

Isotechpl is leading Environmental Chamber Manufacturers and exporting company for Environmental Test Chamber, Scientific Instruments with specialization in all the Sectors with all the necessary Standards having accuracy just equivalent to Imported Calibration Instruments, resulting in import substitute for Indian users.

The company ensures maximum satisfaction both in Quality and Product up-gradation of environmental chambers, maintaining the highest industry standards.