NO BLANKS -- proprietary databases for compliance with NEC IEEE and other standards.
Compliance with NEC and Other Codes
PowerCalc is smart with a proprietary database. It automatically calculates all electrical engineering values to design the entire power distribution system in a building in compliance with the NEC, IEEE Standards 141 and 399, other applicable codes and engineering standards and NEMA requirements. more on NEC and other standards
Electrical values across the entire power distribution system are integrated by over 7 million+ calculations.
PowerCalc selects appropriate values from its fully populated proprietary data base for compliance with the NEC and other applicable codes and engineering standards. This proprietary data base includes the NEC look up tables. more on inputs / outputs
Manual Override
Although PowerCalc automatically defaults to the appropriate values of the NEC and other standards, the user can elect to manually override these inputs / outputs for project and design requirements.
PowerCalc™ is a new way to do the electrical design of the power distribution system in the cloud and automated. Just 3 inputs per circuit results in over 300 NEC compliant outputs for an accurate total electrical load. 1 Line Diagram is automatically, graphically and simultaneously generated. Complete with the free user guide for electrical engineering. Start a free 30-day trial today: www.powercalc.co
To take you behind the scenes at PowerCalc, we’re putting together a mini-series about our people and all the things they do.
As part of our Quality Program, Jessica and James work together consistently on all coding changes and updates. We are continuously testing to ensure the quality of our software in compliance with the best agile and lean software development processes.
More on our series Quality at PowerCalc.
Over Memorial Day 2017, members of the PowerCalc team were with colleagues at the joint meeting of the Engineering Societies of Alabama and Mississippi in Orange Beach, AL.
We had a lot to say and demonstrate.
More on Alabama and Mississippi Engineering Societies 2017.
CONSULTING-SPECIFYING ENGINEER’S
The announcement is just in that PowerCalc is a finalist in Consulting-Specifying Engineer’s Product of the Year contest. The winners are decided by your vote…and electricals, we need your vote!
PowerCalc is in the “Software: Design, Modeling, Analysis” category. And for more details, here is the summary from our application:The winners will be announced in mid-July with gold, silver and bronze awards. Meanwhile, the full list of finalists will be listed in the April 2016 issue of Consulting-Specifying Engineer magazine.
EASY, FAST, SMART, and GREEN electrical engineering design for buildings. PowerCalc™ is the first SaaS-based software that completely automates the electrical engineering calculations for the Building, Construction, and Facility Management Industries in compliance with the National Electrical Code (NEC). Just 3 easy inputs per circuit calculates over 300 NEC compliant outputs – a building’s entire power distribution system from the light bulb to the power grid. And changes are instantaneous.
More on our participation in the Consulting-Specifying Engineer’s Product of the Year contest.
A while ago, we started a discussion on the conductor. It seems like a relevant topic to re-consider in a multi-part series.
In analyzing the power distribution system in a building, the electrical engineer and designer can think of the panelboard as the heart, the conductor as the veins and arteries, and the electrical power as the blood. Continuing this analogy, the important characteristics of the conductor include whether it is fat or skinny, thickly or thinly dressed in insulation, and multicolored or monochromatic for phase and ground/neutral conductors respectively.
Most of the requirements of the National Electrical Code (NEC) are centered on the conductor. And there are many types: service conductors, service entrance conductors, feeder conductors, branch circuit conductors, ground conductors, and neutral conductor. Each type is part of the facility’s power distribution network allowing electricity to flow from the service at the power grid to the branch circuit load.
The factors to be considered in meeting the NEC’s meticulous and confusing requirements include: total load served, continuous and non-continuous load, coincidental and non-coincidental load, conductor insulation (TW, THW, THHN, etc.), system voltage and phase, voltage drop, temperature limitation, temperature correction factor, adjustment factor (number of conductors in a raceway), special conditions/applications (current carrying conductor and tap rule), ground electrode conductor, equipment grounding conductors, conductors in parallel, and load types (receptacle, lighting, or air conditioning). PowerCalc and the NEC
The complexity of this intertwined distribution network results in tedious calculations for the electrical engineer and designer. All are simplified with just 3 inputs per branch circuit by PowerCalc: load (kVA), load type, and number of poles.
More on Anatomy of a Conductor Part 1.
Once the size of the conductor is calculated and the number of conductors determined, the electrical professional continues by calculating the size of the conduit containing these current carrying conductors. See NEC Chapter 9, Table 1, Annex C1 through C12A. When the base current value is determined, the electrical professional then proceeds through the following sequence of calculations to determine:
(1) the overcurrent protection device (OCPD), see NEC Article 240
(2) the ground conductor, see NEC Article 250
(3) the voltage drop, see NEC Article 215
With these basic calculations completed, the electrical professional then applies the remaining factors: continuous and non-continuous load, coincidental and non-coincidental load, temperature limitation, temperature correction factor, adjustment factor (number of conductors in a raceway), special conditions/applications (current carrying conductor and tap rule), ground electrode conductor, conductors in parallel, and load types (receptacle, lighting or air conditioning).
More on Anatomy of a Conductor Part 2 - Sizing the Conductor
Base Current Value
In Part 1, we discussed the different types of conductors in relation to their location in the building's power distribution system and the service provided. Anatomy of a Conductor, Part 1 The types are service conductors, service entrance conductors, feeder conductors, branch circuit conductors, ground electrode conductor and neutral conductor. The factors to consider in meeting the NEC's detailed but confusing requirements were also listed. Then in Part 2, we discussed sizing the conductor. Anatomy of a Conductor Part 2
Back to factors, those for consideration by the electrical professional can be organized into three categories: (1) Primary Factors, (2) Secondary Factors and (3) Ancillary Factors.
Primary Factors are those used to determine load as "seen" by the conductor: (1) system voltage, (2) system phase, (3) equipment # of poles, (4) equipment utilization voltage and (5) total electrical loads.
Secondary Factors are those that impact the size and type of conductor as referenced in the NEC. These include: (1) temperature limitations, (2) temperature correction factor, (3) adjustment factor, (4) equipment grounding conductor, (5) load type (receptacle, lighting, motor and welding equipment), (6) conductor insulation (TW, THW, THHN and others), (7) ground electrode conductor and (8) material (CU or AL).
Last, there are the Ancillary Factors that support the Secondary Factors. These are design driven and considered in relation to installation. They include: (1) voltage drop, (2) conductors in parallel, (3) tap rule, (4) current carrying conductor, (5) demand load calculation and (6) amperage interrupting capacity (AIC).
The outcome of applying the Primary Factors is the base current value in AMPS. The designer based on design requirements and location, then applies the Secondary Factors to obtain conductor size and the associated overcurrent protection device (OCPD). Once these 2 basic values are determined, then the designer finally applies the Ancillary Factors to complete the design and specify the correct wire size and insulation rating.
Voltage Levels
The Primary Factors are applied as part of the following basic engineering equation for power to determine the base current value (l).
P = l x V x √3 for a 3 Φ distribution system
P + l x V for a single Φ - 1 pole and single Φ - 2 pole distribution system
Where P stands for Power (VA); V stands for Volt (V); l stands for Current (A)
Any electrical circuit, in its simplest form, consists of two wires which carry electrical current at a voltage level (electrical potential). The motion of the free electrons (charges) in a given electrical potential in a solid conductor constitutes an electric current (l). Said electric current (l) travels at the speed of light (186,000 miles/second). The unit of electric current is Ampere (Amps). One Ampere of current = 6.251 x 10 to the power of 18 electrons pass given cross section in 1 sec.
The higher the voltage, the higher the current flow for a given resistance. The flow of current (l) in an electric circuit is impeded by the resistance (R) [R = V / l] and produces heat (wasted energy). This wasted energy can be calculated by the following equation: P = l² R.
It is because of this equation, one should properly size the conductor to minimize wasted energy.
Distribution systems in a building are classified according to the voltage level used to transfer the power needed to operate its equipment. The most common distribution system voltage levels that are widely used in the United States are:
480Y / 277 V 3 Φ; 208Y / 120 V - 3 Φ; 230 V closed Δ, 3 Φ; 230 V open Δ; 230 V - 2 poles, 1 Φ; 120 V - 1 pole
In summary, the voltage, the phase, equipment # of poles, equipment utilization voltage and total electrical loads determine the base current value.
More on Anatomy of a Conductor Part 3 - Voltage Levels and Base Current Value.
NEC Article 100 "Definitions" defines branch circuit (BC) as "The circuit conductor between the final overcurrent protection device (OCPD) protecting said circuit and the outlet(s)." The same article also defines outlet as "A point on the wiring system at which current is taken to supply utilization equipment."
Combining the base current value previously calculated in Part 3 of this series, with the two definitions above, the complete design of the branch circuit requires the following:
A branch circuit is rated according to the trip setting of the OCPD that protects the circuit conductors (NEC Section 210.3), with some exceptions that will be discussed at length in future articles.
NEC Article 100 also tells us that there are four (4) types of branch circuits:
The NEC distinguishes and defines these four (4) types of branch circuits because it limits the OCPD rating of any branch circuit with more than one outlet to 15, 20, 30, 40 and 50 Amps (See NEC 210.3). This requirement also applies to branch circuits other than individual branch circuits. As an example, if you have a 60 Amp or 25 Amp branch circuit with two (2) or more outlets, then this requirement is not applicable.
NEC Article 100 also includes in the definitions of receptacle (RCPT), that a duplex RCPT is considered to be two (2) outlets. Any branch circuit for a duplex RCPT must also conform to the requirements of NEC 210.3, and any outlet rated above 50 Amps should be connected on an individual branch circuit.
As a field note: it is an observation that an indoor air handling unit (AHU) with heating strip and the associated outdoor condensing unit (CU) are sometimes observed to be designed on a single one (1) 60 Amp circuit. This is a direct violation of NEC 210.3.
More on Anatomy of a Conductor Part 4 - Branch Circuit Basics.
NEC 210.20 Overcurrent Protection requires branch circuit conductors and equipment to be protected as related to the load. Turning to NEC 240.4 Protection of Conductors also states requirements for the branch circuit as related to the conductor's ampacity specified in NEC 310.15, Tables 310.15(B)(16) - 310.15(B)(21) and Tables 310.60(C)(67) - 310.60(C)(86).
The rule is to protect the circuit conductor by applying a circuit breaker at the supply side of said circuit conductor with Trip Amp rating that is equal or less than said circuit conductor's rating. In the case of the motor circuit, this rule is reversed to allow the motor startup in-rush current to go through the OCPD without tripping and opening the circuit.
Where a circuit supplies only motor operated load, then Article 430 should be applied. An example, 5 HP Motor, 208 V, 3 phase, follows:
1. Circuit conductor rating = base current value (FLA) x 1.25 (NEC 430.22)
From Table 430.250, the 5 HP@ 208 V, 3 phase motor FLA = 16.7 Amps
Circuit Conductor Rating = 16.7 x 1.25 = 20.88 Amps
From Table 301.15(B)(16) select #10 Conductor 60 degrees Celsius
2. OCPD = Base current value (FLA) x 2.5 (NEC Table 430.52)
= 16.7 x 2.5 = 41.75 Amps
From NEC 240.6 Standard Ampere Rating select 405Amps
From the above equation, one can determine that Trip Amp setting of OCPD could be more than twice as much as the circuit conductor rating. This indicates that the conductor is NOT properly protected and could overheat under certain conditions such as motor overload or excessive voltage drop.
Where the circuit supplies only air conditioning equipment, then Article 440 should be applied.
Where the circuit supplying loads consisting of motor operating utilization equipment that is "fastened" in place and has a motor larger than 1/8 HP in combination with other loads, the base current shall be calculated as follows:
1.25% x the largest motor + the sum of other loads
Base current = 1.25 largest FLA + sum of other loads
In summary, the electrical professional should always specify the rating of the OCPD and the rating of the circuit conductor as a "pair". The circuit conductor rating is based on the load and the OCPD rating is based on the load type.
There are other factors that affect the conductor rating such as the ambient temperature and the number of conductors in a raceway.
More on Anatomy of a Conductor Part 5 - More on Branch Circuit Basics.
In the previous articles, we learned how to calculate the base current value for the branch circuit. Using this current value, the designer should determine / select the correct conductor size for the branch circuit. The selection of the conductors for the branch circuit should be based on the secondary factors and the auxiliary factors previously discussed or to be addressed in future articles in this series.
To refresh, the secondary factors are: (1) temperature limitation, (2) temperature correction factor, (3) adjustment factor, (4) equipment grounding conductor, (5) load type, (6) conductor insulation type, and (7) material the conductors are made of.
We will now examine one of the Secondary Factors - temperature limitation and its effect on selections related to the design of the branch circuit conductors.
The temperature limitation of branch circuit conductors is mentioned in two articles of the NEC.
(1) NEC Article 110 Requirement for Electrical Installations Section at 110.14 (C) Electrical Connections states: "The temperature rating associated with the ampacity of a branch circuit conductor shall be selected and coordinated so that as NOT to exceed the lowest temperature rating of any connected termination, conductor, or device." The same paragraph goes on to state: "Conductors with temperature ratings higher than specified for terminations shall be permitted to be used for adjustment, correction, or both."
(2) NEC Article 310 Conductors for General Wiring, Section 310.15 Ampacity for ConductorsRated 0 - 2000 Volts, Paragraph (3) Temperature Limitation of Conductors continues these requirements: "No conductor shall be used in such a manner that its operating temperatures exceeds that designed for the type of insulated conductor involved."
When you look at the ampacity tables, you will see that each table is broken into two parts that identify the material the conductors are made of (CU conductors and AL conductors). Each part is then broken into 3 columns that identify the different temperature rating of the branch circuit conductor. These temperatures are 60, 75, and 90 degrees Celsius. Each of these columns then lists the Type of Insulation (TW, THW, and THHW) used in the branch circuit conductor. Then, you can determine the branch circuit conductor size and its associated ampacity.
In summary, the temperature rating of the branch circuit conductor should match termination points where the branch circuit conductor lands. The higher rated ampacity for the branch circuit conductor(s) cannot be used unless the terminals where the branch circuit conductors land have comparable ratings. Most termination for systems rated at 600 V or less are rated for 60 degrees Celsius for branch circuits rated 100 Amps or less, and 75 degrees Celsius for branch circuits rated over 100 Amps. For systems rated over 600 V, the terminals are designed for branch circuit conductors rated for 90 degrees Celsius and higher.
More on Anatomy of a Conductor Part 6 - More on Branch Circuit Basics, Temperature Limitation.
Concepts of the NEC is one of our topics at next month's Engineering Societies of Alabama and Mississippi's summer meeting on June 10-12th in Biloxi, Mississippi.
The NEC has dual purposes of safety and cost/resource effective design. To summarize: (1) safety concerns (avoid underdesign) and (2) efficient design concerns (avoid overdesign).
Underdesign. As electrical professionals, we are familiar with safety concerns...don't underdesign a power distribution system due to concerns over potential electrical fires. Public safety is always our first concern.
Overdesign. But the second concept, overdesign is also a key part of the NEC. For the most part, this concept is overlooked in today's electrical design. It is simply too difficult to do all of the necessary calculations to implement efficient design. Why - time constraints, looming deadlines and lack of knowledge about the NEC's requirements.
Despite our difficulty in avoiding overdesign, it is a primary concept behind all the NEC articles put together over the years since the first article was written. Right up there with the concept of safety.
To avoid overdesign and right size design a power distribution system, the NEC breaks the demand load into resistive, motor (inductive) and lighting loads. Breaking the demand load into types of loads allows for the design of an optimum power distribution system.
By just adding all the loads (kVAs) up, the demand factors offered by the NEC cannot be applied. Loads must be tracked by load type in order to reduce the connected load sum by the relevant demand load. This process is outlined in NEC Article 220 Branch Circuit, Feeder and Service Calculations. Unless this process is followed, the total load cannot be reduced so the power distribution system is overdesigned.
A threshold issue when we put together PowerCalc, was to track demand loads incorporating the NEC's demand factors as a default in the automatic calculations. The user can always override these factors, but the NEC baseline is always recognized.
What's the result of not paying attention to this mandate of the NEC? Electrical professionals have over coppered facilities causing developers, owners and clients to get some big bills for overdesigned power distribution systems (specifying too much or oversized electrical equipment).
Electrical equipment is expensive, and clients and the world appreciate money and resources saved by not specifying unnecessary equipment. The savings are always substantial when overdesign is avoided.
So, back to Biloxi, we've touched on a few issues, but there are a lot more. For engineers who design facilities, we promise a compelling discussion. Hope to meet our colleagues and will work on a video to share with those who cannot attend.
Biloxi is an incredible place and these Engineering Societies put together a great program and have a lot of fun.
More on Concepts of the NEC: Safety & Efficient Design.
We'll be speaking about:
Morning Session: Automation, Cloud and Real Time: Technology for Electrical Engineering
Afternoon Session: Conceptualizing the NEC: Translation to Code
Initially, we'll discuss how automation makes electrical engineering easier, faster, smarter and greener. You'll even get to see the first automatic, graphic and real time 1 Line Diagram.
Then, we'll turn to the NEC for a discussion of how it is organized...the concepts behind the PowerCalc software. This includes a discussion of the NEC's dual purposes of safety and cost/resource effective design.
For engineers who design facilities, we promise a compelling discussion. Hope to meet our colleagues, and will work on a video to share with those who cannot attend.
Biloxi is an incredible place and these Engineering Societies have put together an incredible program.
More on Mississippi/Alabama anual convention.
It's all about technology and workplace collaboration in today's world. In Biloxi, we had the opportunity to discuss these issues with engineers at the Mississippi-Alabama Engineering Societies' meeting from June 10 -13th.
Our first topic was Automation, Cloud and Real Time: Technology for Electrical Engineering followed in the afternoon by Concepts of the NEC: Translation to Code.
Understanding and adopting advancements in software is vital to the practice of engineering. And importantly, this is a subject best handled by the engineers who understand what their practice is about rather than by coders divorced from the engineering process.
So, down at the Gulf there were lively discussions about NEC compliance and software. How to automate the electrical engineering design process to increase productivity, skills and collaboration while reducing the labor intensive burden of NEC compliance.
PowerCalc (covered by US Patent # 7,636,650) took center stage as the lab rat illustration of how the automation of electrical design for power distribution systems in buildings makes electrical engineering easier, faster, smarter and greener.
Slides Presentation Alabama and Mississippi Engineering Societies 2018 - Concepts of the NEC.
The inventor, James Khalil, PE, walked through how he conceptualized the NEC to write software that produces incredibly accurate results all in compliance with the NEC. Read his discussion below.
More on Mississippi/Alabama engineering societies: Concepts of the NEC.
August 28: West Palm Beach
August 30: Miami
September 11: Orlando
September 13: Tampa
We'll be speaking about:
First Session: Automation, Cloud and Real Time: Technology for Electrical Engineering
Second Session: Conceptualizing the NEC: Translation to Code
Initially, we'll discuss how automation with 7 +million calculations makes electrical engineering easier, faster, smarter and greener. You'll even get to see the first automatic, graphic and real time 1 Line Diagram.
Then, we'll turn to the NEC for a discussion of how it is organized...the concepts behind the PowerCalc software. This includes a discussion of the NEC's dual purposes of safety and cost/resource effective design.
For engineers who design facilities, we promise a compelling discussion. Hope to meet our colleagues, and will work on a video to share with those who cannot attend.
The Florida Engineering Society has put together an incredible program. Mark your calendar!
The headline and sub-header tells us what you're offering, and the form header closes the deal. Over here you can explain why your offer is so great it's worth filling out a form for.
More on Automation / Concepts of the NEC for Florida Engineering Society.
We'll be speaking about:
First Session: Automation, Cloud and Real Time: Technology for Electrical Engineering
Second Session: Conceptualizing the NEC: Translation to Code
Initially, we'll discuss how automation with 7 +million calculations makes electrical engineering easier, faster, smarter and greener. You'll even get to see the first automatic, graphic and real time 1 Line Diagram.
Then, we'll turn to the NEC for a discussion of how it is organized...the concepts behind the PowerCalc software. This includes a discussion of the NEC's dual purposes of safety and cost/resource effective design.
For engineers who design facilities, we promise a compelling discussion. Hope to meet our colleagues, and will work on a video to share with those who cannot attend.
The Florida Engineering Society has put together an incredible program.
We had a great time with all the engineers in West Palm Beach and Miami. And, we look forward to meeting more engineers in Tampa and Orlando!
More on Orlando and Tampa: Automation / Concepts of the NEC for Florida Engineering Society.
Our patented technology calculates all the values for the 1 Line Diagram with our 7+ million equations. And now, these electrical engineering values are also visual. PowerCalc makes electrical engineering design so easy!
To respond to all of your questions, we are providing free webinars every Thursday through March 29th, 2018 at noon EST. So, join to discuss the 1 Line Diagram, PowerCalc, the NEC, electrical engineering, particular projects, your engineering issues, your engineering calculations, whatever is on your mind.
Watch PowerCalc's technology in action on a school for the Broward County School System in Florida, the largest school system in the country. It is an incredible illustration of the effectiveness of PowerCalc's 1 Line Diagram for renovation projects. The 1 Line serves as the starting point to determine the renovation design's impact on the existing power distribution system.
Find out why Ken Everett from Seattle says:
"I started using PowerCalc not long ago and I'm not very computer savvy. It is really amazing how simple PowerCalc is to use and how user friendly. I just got my first set of drawings back from the Seattle Building Department with zero corrections / comments...it was great. I would recommend PowerCalc to anyone."
Demonstration of PowerCalc™ basics, 1 Line Diagram, voltage drop, fault current calcs and AIC ratings. Q and A.
More on our Webinar PowerCalc Overview, Voltage Drop, Fault Current Calc and AIC.
Deep Dive into Voltage Drop: What it is, why it is, and how Powercalc calculates it automatically.
More on our Webinar Deep Dive into Voltage Drop.
Deep Dive into Fault Current Calculation: What it is, why it is, and how Powercalc calculates it automatically.
More on our Webinar Deep Dive into Fault Current Calculation.
Deep Dive into AIC Ratings: What it is, why it is, and how Powercalc calculates it automatically.
More on our Webinar Deep Dive into AIC Ratings.
Final Webinar, Roundup on PowerCalc, 1 LIne, Voltage Drop, Fault Current and AIC.
More on our Webinar Deep Dive into AIC Ratings.
Auto design of Power Distribution System + 1 Line Diagram + Fault Current Calc.
We've done lots of demos for new users and put together a video for you. Watch and see how PowerCalc(tm) makes electrical design easier, faster, more accurate, and more profitable.
Click on the arrow to walk through the demo of PowerCalc(tm). First, we start at the circuit, move on to the panels, and watch the 1 Line Diagram being simultaneously built throughout the process.
More on our Webinar On Demand Demo: get started with PowerCalc (tm).
PowerCalc is patented software that calculates all the values for the power distribution system in a building and the 1 Line Diagram with 7+ million integrated equations. Just 3 inputs per circuit (load kVA, load type, and # of poles) results in over 300 NEC compliant outputs.
