2018 NFPA 70E Update – What’s New? What’s Changed?
Published: June 2017 By Jim Phillips Based on Jim’s article originally published in theMay 2017 Issue of Electrical Contractor Magazine. It is hard to imagine that three years have passed since I wrote […]
Arc Flash Study Top 10 FAQs Part #3
How Does Everyone Else Do This? By Jim Phillips 3-Part Series ARC FLASH LABELS What do you list on an arc flash label when the prospective incident energy is […]
Arc Flash Study Top 10 FAQs Part #2
How Does Everyone Else Do This? By Jim Phillips 3-Part Series ELECTRICAL SAFETY PRACTICES Does your company or client permit energized work where the incident energy is greater than […]
Arc Flash Study Top 10 FAQs Part #1
How Does Everyone Else Do This? By Jim Phillips 3-Part Series There are many frequently asked questions about performing an arc flash study (risk assessment) and understanding electrical safety […]
Forensic Electrical Engineering Blog #3
Past – Present – Future 3-Blog Series By Jim Phillips, P.E. Blog #3: Evolution in Forensic Electrical Engineering There has been much advancement in the field of forensic electrical […]
Forensic Electrical Engineering Blog #2
Forensic Electrical Engineering Past – Present – Future 3-Blog Series By Jim Phillips, P.E. History of Forensic Electrical Engineering Some historical articles suggest the field of electrical investigations began […]
Forensic Electrical Engineering Blog #1
Past – Present – Future 3-Blog Series By Jim Phillips, P.E. Blog #1: What is Forensic Electrical Engineering? Welcome to my 3-part blog series about the Past, Present and […]
Moisture Content in Electrical Cabinet
Question: Hello, At one facility I find that the condensation gathers on the inside surface of an enclosure, which can cause the rusting, short circuits, and breakdowns in electric and […]
IEEE 1584.1-2013
Question: Hello, good afternoon. Does the standard contain new information to consider for arc flash analysis? Thank you Answer: No because we’re still on the 2002 edition. The new […]
Liability and Legal Action
It’s no secret that the United States is a very litigious country. Sometimes the more “interesting” interpretations that people use regarding codes, standards, design etc. tend to be more influenced […]
Evaluation of Onset to Second Degree Burn Energy in Arc Flash
Our interest in determining accurate onset to second degree burn energy and its significance in computing the arc flash boundary is focused on the prevention of injury to the skin […]
Include Date on Arc Flash Label?
According to the 2015 Edition of NFPA 70E 130.5(2), The arc flash risk assessment “…shall be reviewed periodically, at intervals not to exceed 5 years, to account for changes in […]
Adjusted Pickup Method – Shift Factor
I have been looking into the adjusted pickup method and associated shift factors used when multiple source bus configurations are being coordinated [ex. parallel generator systems two or more] and […]
Non-melting clothing
Our company in the past 2 years has implemented an electrical safety and control of hazardous energy program for employees world-wide. Our daily work-wear clothing minimum requirement is non-melting clothing, […]
Behavior of Apparel Fabrics During Convective and Radiant Heating
Personal protective equipment (PPE) recommended for arc flash is not always designed for arc flash exposure. The purpose of this paper is to warn of the dangers posed by using […]
Safe Return-to-Service Following a Maintenance Outage
Best Practices for a Safe Return-to-Service Following a Maintenance Outage Charles M. McClung, MarTek Limited Russell R. Safreed, PE, MarTek Limited Abstract Returning electrical equipment to service after a planned […]
2015 NFPA 70E Changes
The following is an article that I wrote a few years ago listing the major changes for the 2015 edition. It was originally published in the May 2014 issue of Electrical […]
Short Circuit Data – Per Unit, Amps and Symmetrical Components
Making Sense of the NumbersUtility Company Short-circuit Data For Arc Flash Studies Electrical Contractor Magazine – November 2012Jim Phillips, P.E. One of the first steps in performing an arc flash […]
How Many Arc Flash Labels on Equipment?
Question of the Week Some equipment may have multiple arc flash labels for a variety of reasons. Different operating configurations Equipment is long/large – including busway Equipment has different incident […]
Medium or high voltage training in U.S.
Recently a Fortune 500 company called asking if service technicians were “certified” to work on 4160 V equipment. This isn’t in the context of say the New Brunswick province where […]
Face equipment or face away during switching?
Weekly Question: This week’s question was submitted from one of our forum members. I will post it here When locking out or resetting a tripped breaker on a CAT 4 […]
ATS Protection and UL
In looking at the latest edition [7th] of UL 1008 for transfer switches I came across the following: “The circuit breaker must include an instantaneous trip response and shall not […]
Hot Stick Testing
Question: Everyone, I got this question from a client. He asked if it’s necessary to have their hot sticks tested? Understand this company has nothing higher than 480 volts on […]
Regenerative Drive Contributions to Upstream Fault
Is there any information on what a regenerative drive will allow a motor to contribute to an upstream fault? I know ANSI has some standards for motor contributions based on […]
Arc Flash Labels-PPE Category
In the NFPA 70E-2015 Handbook, page 122, 130.5(D) states incident energy or PPE category shall be on the equipment arc flash label, but not both. Yet when reviewing Annex H […]
Reducing Arc Flash I/E At Fire Pump Controllers
Question: What are you guys recommending to reduce incident energy levels on fire pump controllers fed directly from the secondary side of utility transformers? Answer: Can’t be done. This is a […]
Work on an energized disconnect
Recently, a client asked if there was something I could point to in the NFPA 70E Standard that specifically prevented a qualified electrician from working on a disconnect after it […]
120 Volt Arc Flash
I believe it to physically impossible to sustain an arc flash at 120 V but can someone point me to the proof? Can someone indicate where a code specifically states […]
Arc Flash Label Updating – How Many Times?
NFPA 70E requires that an Arc Flash Risk Assessment be updated when a major modification or renovation takes place. It shall be reviewed periodically, at intervals not to exceed 5 […]
Picture of the Week
Hopefully you’ll never have to experience this on the job! Male chimpanzee Chacha screams after escaping from nearby Yagiyama Zoological Park as a man tries to capture him […]
Using gloves with a stick
1910.269 requires arc flash protection for hands with exceptions when wearing leather protectors over rubber gloves, and when wearing heavy duty work gloves. The workers state that sticks should be […]
DC Arc Flash Boundary
Could i use the (DB) empirically derived model equation of IEEE Std 1584-2002 to calculate the Flash-protection boundary (for box configurations) and the Lee (DB) equation (for open air configurations)? […]
100A panel with 200A “gutter mounted” main. WTF??
Came across this today while surveying. The original drawing shows this panel with a 100A branch mounted main. Well, someone needed that breaker for another panel and removed it and […]
ANSI Z535 – Series of Standards for Safety Signs and Tags
Many safety labels use either Caution, Warning or Danger with a specific color associated with it. The U.S. National Electrical Code and NFPA 70E both reference ANSI Z535 to provide […]
Maintenance of LV components inside HV cabinet
Good Morning All, I am from the Safety Office and our organization prohibits working on electrical components/systems above 600V. I have a situation that I need advice on. Here is […]
RELT or ARM Arc Flash Labels
It always seems as if we are kicking the dead horse on arc flash labels but I was just interested in your opinion of how to label a piece of […]
Maximum distance where arc flash label is still readable
This week’s question is very subjective and is based on all kinds of variables such as lighting, eye sight etc. For an average person under normal conditions: What is the […]
I wonder what the withstand rating is on these?
I’ve known about these switches in this old house for at least 15 years but never took any pics. I was over there today and thought I would share to […]
2017 NEC 240.87 Instantaneous Trip
The NEC requires that where a circuit breaker’s highest continuous current trip setting is rated or can be adjusted to 1200 Amps or higher, a method for reducing the arc […]
Low Fault Current on Utility System
Here is the situation: It is a municipal system, very rural, and has long single phase runs with low fault current. For example: 2400 delta single phase lateral ends up […]
Easy way to get a series combo rating – sometimes??? Maybe?
Hi all. As I continue to slog through my list of 104 buildings on campus I need to do studies on I discovered yet another over-dutied situation yesterday. Common scenario, […]
Do you use equipment/methods based on IEC Standards?
This week’s “Question of the week” is coming from Frankfurt, Germany. This week I have the privilege of attending the International Electrotechincal Commission’s 80th General Meeting as the International Chairman […]
Jim Phillips, P.E. Awarded the Member of the Institution of Engineering and Technology – MIET
Jim Phillips, P.E. Awarded the Member of the Institution of Engineering and Technology – MIET LATEST NEWS October 10, 2016, Scottsdale, AZ: On February 15, 2016 – Stevenage (London), England […]
Arc Rated Clothing Causing Health Effects
We have gone to wearing cotton HRC2 (8.6 cal/cm2) uniforms and about 10% of the employees have found the clothing to cause burning and itching with at least one case […]
Air Conditioner Motor Contribution
I’d like to hear how some of you are handling Air Conditioner motor contributions in your models. I’m working off a one-line to build the model (while the site is […]
Lock Out / Tag Out Simple vs. Complex
OSHA and NFPA 70E refer to a Simple LOTO as involving only one person/conductors/circuit part(s). A Complex LOTO is when there are conditions such as more than one person/circuit/shift/source involved […]
IEEE 1584 and Overdutied Breakers
I guess this directed at IEEE 1584 Committee members (Jim) and I know you can’t say too much but is overdutied breakers/equipment going to addressed in the new IEEE 1584? […]
Jim Phillips, P.E. Joins Electrical Safety UK as Associate Director
Jim Phillips, P.E. Joins Electrical Safety UK as Associate Director LATEST NEWS October 3, 2016, Scottsdale, AZ: On August 4, 2016 Jim Phillips P.E. joined Electrical Safety UK as an Associate […]
Replacing AF Labels
I will be updating arc flash labels on numerous working locations which means the old label has to be removed and a new one applied. By design these labels are […]
Aluminum vs. Copper IE differences
I’m pushing through the brilliant book “Industrial Power System Grounding Design Handbook” by Dunki-Jacobs and Co. In it, the authors indicate that copper is endothermic (absorbs energy when converting from […]
How far would you go?
All – I found this installation the other day while in an area I am not officially in charge of. I called the person in charge and recommended he have […]
Falsified Arc Flash Study
As a electrical engineer who performs arc flash studies and investigates electrical accidents I have come across a company who is faking their arc flash studies. They go into companies […]
International Electrotechnical Commission Committee 78 Approves New Chairman
International Electrotechnical Commission Committee 78 Approves New Chairman LATEST NEWS September 26, 2016, Scottsdale, AZ: Jim Phillips, P.E., founder of Brainfiller.com and ArcFlashForum.com was recently nominated and approved as the […]
AF Boundary Marking
Hi, As per NFPA 70E, we have 3 boundaries to mark(AFB, limited and restricted). It is easy to mark and follow only one boundary which is greater than two. Sometimes […]
Short sleeves versus long sleeves
The industrial plant I work in has a policy that you must have long sleeves when inside an electrical room. Yesterday we had our annual “cold day”, where all turbine […]
Application range of methods in IEEE1584
Hello everyone, The application range for the empirical method is clearly defined : 208V to 15kV and a bolted fault current between 700A and 106kA. But for the theoretical method, […]
Arc flash detection relay
What is the practice for the use of arc detection relay trip time in the arc incident energy calculations? NFPA-70E recognized arc detection relay but kept under “Other Methods” as […]
Jim Phillips to Speak at 2016 IEEE/ESMO Conference
LATEST NEWS September 12, 2016, Scottsdale, AZ: Jim Phillips, P.E., founder of Brainfiller.com and ArcFlashForum.com, will be a speaker at the 2016 IEEE/ESMO conference held in Columbus, OH on […]
NFPA 70E
AS I understand it in NFPA 70 E 130.7 table any Panel 240 volts and below require Category 1 PPE. Also NFPA says any voltage 120 volts Phase to Phase […]
Underrated/Over dutied panels in an old building…..WWYD?
We’ll call this a hypothetical question. Say you are running a short circuit and arc flash study on a 50 year old building as part of a multi-building study. You […]
Have you ever read IEEE 1584?
Just Curious – Have you ever read IEEE 1584 – IEEE Guide for Performing Arc Flash Hazard Calculations? -All of it -Some of it -No Click to ANSWER.
Bus Duct and Arc Flash Hazard?
I was asked to evaluate some “newer” bus duct technology that are finger safe, use a turn and lock connection or similar methods without turning off the power. It seems […]
Adding fuses or a CB in a pad mount transformer secondary
Hi All. I know I’ve seen a picture or two of your typical oil filled pad mounted transformer that had fuses or a breaker installed right off the paddles on […]
Grounding….
Looking at the IE calculation there is a variable for grounding depending on what type system you have installed, and noticed that the grounding type can have a significant effect […]
Using Grounding Resistors
One of the forum member’s posts prompted this weeks question of the week. It is about grounding, more specifically – high and low resistance grounding. (some may use reactance grounding). […]
MCA – Minimum Circuit Amps?
How does one calculate the normal operating current of a load from the MCA rating, given that is all you have. Thanks. CLICK to Answer.
Preload indicating washers
Anyone ever heard of a preload indicating washer? Looks very simple. It’s a washer that crushes when the fastener reaches 80% of yield. According to Sandia Report SAND2008-0771 they are […]
Using the series rating charts – real example
Don’t mean to beat this topic to death. Well, yeah, I guess I do, but since I had another example of being over dutied/under rated come up today I thought […]
NFPA 70E and Improved Electrical Maintenance
The duration of an arc flash can be greatly affected by the condition of electrical protective devices – i.e. circuit breakers, relays etc. NFPA 70E has been placing an increased […]
Tested vs. Engineered Series Ratings
One more question about series ratings. NEC 240.86 addresses series ratings “Selected Under Engineering Supervision in Existing Systems” and “Tested Combinations” Please refer to last week’s post and NEC 240.86 […]
Racking in medium voltage breakers – does this exist?
The question of the week on racking in medium voltage breakers got me thinking about this video: https://www.youtube.com/watch?v=rdQR7-Ap6YQ and what else could be done to prevent it from happening again. […]
Series Ratings NEC 240.86
The National Electrical Code article 240.86 addresses series ratings with the following: Where a circuit breaker is used on a circuit having an available fault current higher than the marked […]
IEEE 1584 – Required Certification for Products/Services?
I have heard a rumour that IEEE1584 are up to their old tricks again. Back in 2012 it was to introduce royalties for use of the equations. This time I […]
New to Arc Flash, Short Circuit and Coordination studies
Hi. I currently work as an Engineer in the energy management field. I would like to branch off in to doing Arc Flash, Short Circuit and Coordination Studies. How would […]
ArcPro and Windows 10
Has anyone found a way to run ArcPro on Windows 10? I cannot even install it on Windows 10. Not sure about any 3rd party programs that could emulate a […]
X factor for Disconnect switches
Hello What is the optimal X factor for disconnect switches. I assumed it is 2 because that’s the default value that ETAP gives you. Am I correct for assuming this? […]
PE/Certification (moved from IEEE 1584 Certification thread)
There is a long and well documented fight between the NSPE as the “political arm” of professional engineering and various industry groups which have all but made “industrial exemption” here […]
Arc Flash Shields in disconnect boxes
I repair UL listed appliances that are sometimes directly wired into a fused or unfused disconnect box if they exceed 50A. Sometimes I need to test the voltage on both […]
Existing Overdutied Equipment
This week’s question is a continuation of last week’s topic regarding overcurrent devices that do not have an adequate interrupting rating. When the calculated short circuit current is greater than […]
PPE Selection when Interacting with non-labeled Equipment
Hi All, To put my question in context, I train Industrial Maintenance and Construction Electricians at a Community College. Some of the students are new to the field and are […]
Fiber Optic Arc Flash Detection Modeling
I will start by stating that I am not 100% familiar with these types of systems [Fiber Optic Light Detecting]. In recent MV switchgear submittal the manufacturer [I assume at […]
Arc Flash Boundary – Calculated, Larger, Something Else?
It has been a while since a question of the week was asked about the Arc Flash Boundary. This is the distance from a prospective arc flash where the incident […]
Non Specific incident energy
I have started working at a manufacturing plant where the past practice is to put <1.2 cal on their arc flash labels. The thought being that any run less than […]
Does your company/client(s) have photovoltaic systems?
No secret, there has been quite an increase in the use of photovoltaic (PV) systems. This week’s question is pretty simple: Does your company/client(s) have photovoltaic systems installed? Yes No […]
Photo reminder of the importance of electrical safety.
Here is a photo that is a not so subtle reminder about the importance of electrical safety. Tombstone Photo READ MORE
Improvised U.S. to International Power Adapter
Here is a photo of an improvised global receptacle adapter. Improvised International (Australia) Power Adapter Photo READ MORE
Short Circuit Calculations and Conduit Material
I recently came across a previous study that was completed for a facility that assumed a specific type of conduit [non-metallic/magnetic; PVC] vs what was actually installed [Rigid Meal Conduit], […]
Harmonic Correction Unit?
Would a Harmonic Correction Unit impact the incident energy during an arc flash in an MCC line-up? READ ANSWER
Normalized incident energy explained?
Can someone explain incident energy normalized, what is it and how it is obtained .Utilizing the Incident Energy at Working Distance -Empirically Derived Equation -NFPA 70E-D4.3, En = incident energy […]
Need some TCC curves for two fuses – can’t find them
Hi all. I have a pad mounted transformer with internal primary side 15KV rated fuses. There are two types in series. One is an expulsion fuse GE# 9F54WLD303 and one […]
Overdutied Protective Devices and Catastrophic Failures
People seem to love to watch videos of electrical explosions. One type of failure is when a protective device is applied beyond its interrupting rating and catastrophically fails (explodes) when […]
Utility Short Circuit Current Data, Arc Flash and Change
Webinar – Utility Short Circuit Current Data, Arc Flash Studies and Changeby Jim Phillips, P.E. [See more about Jim Phillips] It goes up, it goes down, sometimes it is thought […]
Arc Flash Hazard Calculation Studies
In the earlier years of NFPA 70E and the emergence of arc flash protection requirements, many people would use the NFPA 70E Hazard/Risk Tables to determine what arc rated PPE […]
IEEE 1584 – 125 kVA Transformer / Less than 240 Volts Exception
One sentence in the IEEE 1584 Standard, IEEE Guide for Performing Arc-Flash Hazard Calculations, frequently has people scratching their heads: Equipment below 240V need not be considered unless it involves […]
Grounding Power Distribution Systems
The NEC contains specific articles that dictate when you shall ground, when you shall not ground, and when you are permitted – but not required – to ground. These code […]
OSHA, NEC, NFPA – Pieces of the Puzzle
The next time you are near the bulletin board at work, look for the poster that has the words “It’s the Law” and “OSHA” on it. It has probably been […]
Testing for Improved Power Distribution Reliability
Those responsible for a facility’s operation hear the same thing over and over again – reduce costs and improve productivity. Much attention has been given to reducing raw material and […]
