PowerCalc won GOLD in Consulting-Specifying Engineers' annual contest for Product of the Year 2016.
Our last newsletter discussed the 7 reasons for winning: the power of (1) the PowerCalc algorithm, (2) the PowerCalc panel, (3) the PowerCalc process, (4) PowerCalc for NEC compliance, (5) the PowerCalc Wizard, (6) PowerCalc in the cloud, and (7) the PowerCalc experience.
Let’s discuss Reason #1 in more detail: the PowerCalc algorithm.
Bottom-Up Process to Automate Design
It sounds small, but the impact is big: design from the bottom – up.
PowerCalc implements this disruptive and patented approach adding electrical loads of each branch circuit to sum up the Total Electrical Load for a facility. PowerCalc designs from the branch circuit to the power grid.
Top-Down Fails Inside Facility
Most electrical engineering software is for the transmission of electricity in the power grid (outside of the facility) and designs from the top-down (power grid to the facility). And, most electrical engineering software for design inside the facility has simply adopted this top-down approach used in the power grid.
This simple adoption fails to recognize that there are two different and separate power distribution systems: (1) the transmission system in the power grid (outside the facility) and (2) the power distribution system inside the facility.
Simply, the power grid’s top-down approach to design the distribution of electricity in the power distribution system inside the facility never worked, never works and never will work.
Confusion: Expensive Mistake
The recurring comment from our customers is how their expensive “power grid” software is sitting on the shelf and never used for their work: the design of power distribution system inside facilities. These purchases are expensive mistakes.
Apparently, these software companies promote confusion by using the terms “distribution” and “transmission” interchangeably when discussing electrical issues in the power grid.
Let’s clear up this confusion: the distribution of electricity in the power distribution system inside the building must meet code and regulatory requirements which are very different from those applicable to the transmission of electricity in the power grid. For this reason alone (and there are lots of other reasons) the design of power distribution systems inside the facility and outside the facility (power grid) are very different.
Power grid software (outside the facility) just does not work inside the facility. In contrast to the concerns for electrical engineering design inside of facilities, these power grid software applications for outside the facility insure that connected systems are compatible and in harmony: (1) within the power grid itself or (2) between the power grid and the power distribution system. Typically, these calculations are “studies” to check that connected systems act together as one electrical system. Examples are fault current studies, harmonic current studies, power flow studies and similar calculations including the actual connection of the building’s power distribution system to the power grid/electrical service.
What is Bottom-Up design inside the facility?
It is a unique approach: PowerCalc starts at the beginning by calculating and aggregating data from each branch circuit to the power grid/electrical service (bottom-up). For each branch circuit, there are 3 inputs: electrical load in KVA, number of poles (1, 2, or 3 poles) and electrical load type (LTG, Heading, AC, etc.). These 3 inputs provide over 300 NEC and other code compliant outputs. Check out More on NEC and Inputs/Outputs.
Why Bottom-Up design is necessary inside the facility?
PowerCalc’s over 7 million integrated equations tied to proprietary databases provides accurate and compliant results. And the integration allows for instant changes across the power distribution design…upstream and downstream. So, it is never a problem to add or change equipment, a room, a wing or any change/update.
Automation drives productivity. This new accuracy and efficiency is game changing: save over 40% in design time and money. Save Time/Save Money. Also, far fewer building department comments, lawsuits, corrections for construction errors and weekend hours.
There should never be an error in the Total Electrical load for any project. Yet, the miscalculation of the Total Electrical Load is one of the most common problems in electrical engineering design.
The proper and only fail-proof way to design the power distribution system in a building is to add all the electrical loads from the branch circuit out to the service entrance with adjustments for changes (bottom-up). Values are aggregated in a 3 step process (1) add all electrical loads by type, (2) apply code demand factors to each load type and then (3) add all electrical loads.
In contrast, guestimating the size of the electrical load in conjunction with pre-sets of panelboard sizes, equipment disconnects, feeders and overcurrent protection devices at the start of the project leads to an inaccurate baseline on which to build the power distribution system design.
This is construction, so change is the standard in our business. So, how can anyone know the size of the electrical service at the start of a project? No one can guestimate the Total Electrical Load in conjunction with the factors identified above at project start. Only by adding all the electrical loads from the branch circuit out to the service entrance can the engineer correctly size and adjust for changes in the electrical load for the project.
The Total Electrical Load drives the success of your electrical engineering design. An addition or subtraction error in the Total Electrical Load results in either electrical equipment being oversized at potentially great cost to the developer or undersized at potentially great risk to the safety of the facility’s occupants.
Let me know what you think…and in our next issue we’ll talk about the power of PowerCalc’s panel. Also, be sure to sign up for our blog at powercalc.co, we start to publish on the 14th.
James Khalil, P.E.
Inventor of PowerCalc