Jun
18

10 Things about Arc Flash Safety

10 Arc Falsh

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Jun
11

Proposed NFPA Standards for Electrical Inspections In the Works

Electrical Inspector GettyImages 177311145 1024

The National Fire Protection Association (NFPA) has two new standards in the works related to electrical inspections and the inspectors who perform them.

The NFPA Technical Committee on Electrical Inspections began work on the proposed standards a year and a half ago. NFPA 78: Guide on Electrical Inspections, and NFPA 1078: Standard for Electrical Inspector Professional Qualifications, both received public input through mid-February this year, and the technical committee is working now on finalizing the first draft of the standards, according to Jeff Sargent, Regional Electrical Code Specialist at NFPA, in a live seminar this afternoon.

The first drafts of the two proposed standards will be released Aug. 22, 2018. If there are no amendments the committee expects to have the final standard by August 2019. If there are certified amendments, the standards will go through a second draft process and be released in August 2020, Sargent said.

He added that the Technical Committee on Electrical Inspections is still looking for more committee members.

NFPA members can find more information, including applications to join the committee, at the NFPA site:

NFPA 78: Guide on Electrical Inspections

NFPA 1078: Standard for Electrical Inspector Professional Qualifications

 

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Jun
04

The 10 Biggest Grounding Mistakes to Avoid

There’s more to proper grounding and bonding than meets the eye. When tackling this type of work, the end goal is obviously to prevent unwanted voltage on non-current-carrying metal objects and facilitate the correct operation of overcurrent devices. But that doesn’t mean wiring everything to a ground rod and calling it a day. In order to provide safe installations to the public, there are certain subtleties you must follow in order to meet applicable NEC rules.

Proper grounding and bonding prevent unwanted voltage on non-current-carrying metal objects, such as tool and appliance casings, raceways, and enclosures, as well as facilitate the correct operation of overcurrent devices. But beware of wiring everything to a ground rod and considering the job well done. There are certain subtleties you must follow to adhere to applicable NEC rules and provide safe installations to the public and working personnel. Although ground theory is a vast subject, on which whole volumes have been written, let's take a look at some of the most common grounding errors you may run into on a daily basis.

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Failure to Install a Second Ground Rod Where Required

A single ground rod that does not have a resistance to ground of 25 ohms or less must be augmented by a second ground rod. Once the second ground rod is installed, it's not necessary for the two to meet the resistance requirement. As a practical matter, few electricians do the resistance measurement and simply drive a second ground rod. If you install a second rod you must locate it at least 6 feet away from the first rod. Greater distance is even better. If both rods and the bare ground electrode conductor connecting them are directly under the drip line of the roof, ground resistance will be further diminished. This is because the soil along this line is more moist. Ground resistance greatly increases when soil becomes dry.

2GroundingMistakesGroundingSatellite


Installation of a Satellite Dish Without Proper Grounding

If you look at all of the satellite dish installations out there, you’ll inevitably find many that are not grounded. Of those that are, there is still a good chance that the installation is not fully compliant. Common mistakes installers should avoid include making the grounding electrode conductor too long or too short, using unlisted clamps at terminations, having excess bends, or connecting to a single ground rod but not bonding to other system grounds. The grounding means for a satellite dish must be located at the point of entrance to the building. In this particular installation, the grounding conductor is integral with the coax from the dish, but the installer did not bond it to other system grounds.

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Improperly Connecting the Equipment-Grounding Conductor to the System Neutral

The grounded conductor (white) and the grounding conductor (bare or green) should not be connected together except by the main bonding jumper in the service equipment. You must connect a grounded neutral conductor to normally noncurrent-carrying metal parts of equipment, raceways, and enclosures only through the main bonding jumper (or, in the case of a separately derived system, through a system bonding jumper). Make this connection at the service disconnecting means, not downstream. It's a major error to install a main bonding jumper in a box used as a subpanel fed by a 4-wire feeder. It's also wrong not to install it when the panel is used as service equipment.

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Failure to Properly Attach the Ground Wire to Electrical Devices

Wiring daisy-chained devices in such a way that removing one of them breaks the equipment grounding continuity is a common problem among electricians. The preferred way to ground a wiring device is to connect incoming and outgoing equipment-grounding conductors to a short bare or green jumper. The bare or green insulated jumper is then connected to the grounding terminal of the device.

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Failure to Properly Attach the Ground Wire to Electrical Devices

Wiring daisy-chained devices in such a way that removing one of them breaks the equipment grounding continuity is a common problem among electricians. The preferred way to ground a wiring device is to connect incoming and outgoing equipment-grounding conductors to a short bare or green jumper. The bare or green insulated jumper is then connected to the grounding terminal of the device.

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Improperly Grounding Frames of Electric Ranges and Clothes Dryers

This image shows two NEC-compliant 4-wire receptacles and an obsolete 3-wire receptacle in the middle. Before the 1996 version of the NEC, it was common practice to use the neutral as an equipment ground. Now, however, you must ground all frames of electric ranges, wall-mounted ovens, counter-mounted cooking units, clothes dryers, and outlet or junction boxes that are part of these circuits by a fourth wire — the equipment-grounding conductor. An exception permits retention of the pre-1996 arrangement for existing branch circuit installations only where an equipment-grounding conductor is not present. If possible, the best course of action is to run a new 4-wire branch circuit from the panel. If you must keep an old appliance, be sure to remove the neutral to frame bonding jumper if an equipment-grounding conductor is to be connected.

7Submersible pump 30 07 2012

Failure to Ground Submersible Well Pumps

Once upon a time, submersible well pumps were not required to be grounded because they were not considered “accessible.” Over the years, however, people started pulling the pump out, laying it on the ground, and energizing it to see if it would spin. As a result, if the case became live (due to a wiring fault), the overcurrent device would not function, causing a shock hazard. Per the 2008 NEC, a fourth equipment-grounding conductor is required that you must now lug to the top of the well casing. Although many electricians assume that one wire is a “ground” in a 3-wire submersible pump system, in actuality, submersible pump cable consists of three wires (plus equipment-grounding conductor) twisted together and unjacketed. Yellow is a common 240V leg, black is run, and red is start, which the control box energizes for a short period of time. Prior to the new grounding requirement, everything was hot.

7GroundingMistakesNon GroundingReceptacle

Here is a non-grounding type receptacle typically found in older homes. The NEC doesn’t say you have to immediately replace all noncompliant equipment with each new edition of the Code. Although it’s acceptable to leave the old “two prongers” in place — because an intact functioning equipment ground is such an obvious safety feature — most electricians tend to replace them. When you find yourself working with non-grounded receptacles, your best course of action is to run a new branch circuit back to the panel, verifying presence of a valid ground. Another possibility is to replace the two-prong receptacle with a GFCI. If replacement is necessary — and acquiring a ground is not feasible — you can also install a new non-grounding receptacle.

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Failure to Bond Equipment Ground to Water Pipe

How many times have you seen an improper connection like this in the field? Here someone used a water pipe clamp to improperly connect a ground wire to this ground rod. Screw clamps and other improvised connections do not provide permanent low impedance bonding. The worst method would be to just wrap the wire around the pipe or to omit this bonding altogether. In a dwelling unit, a conductor must be run to metallic water pipe, if present, and connected with a UL-listed pipe grounding clamp. This bonding conductor is to be sized according to Table 250.66 of the NEC, based on the size of the largest ungrounded service entrance conductor or equivalent area for parallel conductors.

GFCI Outlet1

Not Installing GFCIs Where Required

With the passage of each new Code cycle comes the increased use of GFCIs in more applications. As an electrician, make sure you know when and where these devices are mandatory. In dwelling units, for example, the 2008 NEC notes that GFCIs are required on all 125V, single-phase, 15A and 20A receptacles in: bathrooms; garages; accessory buildings with a floor at or below grade level not intended as a habitable room, limited to storage, work and similar areas; outdoors; kitchens along countertops; within 6 feet of outside edge of laundry, utility, and wet bar sinks; and boathouses. In other than dwelling units, GFCIs are required on all 125V, single-phase, 15A and 20A receptacles in bathrooms, kitchens, rooftops, outdoors, and within 6 feet of the outside edge of sinks.

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May
21

The Evolution of Electrical Safety and NFPA 70E

Examining significant changes in the 2018 edition of the standard

It’s that time of year again — when the days start to get a little bit longer and for those of us up north, a little warmer, too. It is also that magical time every three years when we get to celebrate the latest revision of NFPA 70E, Standard for Electrical Safety in the Workplace, hitting the bookshelves and digital marketplaces in its various forms.

The 2018 edition of NFPA 70E seems to be everywhere you turn in the electrical industry as companies dive in and get to work on updating safety programs to the newly revised requirements. The good news is that safety directors need not panic, as there were few changes that substantially shift the concept of safe work practices around electrical equipment. Many of the revisions in this cycle were aimed more at a continued effort made over the course of the last few cycles. For instance, there’s the hierarchy of risk control methods, an increased emphasis on preventive maintenance for personnel safety, and Art. 120, which was entirely rearranged to follow a more logical progression for establishing an electrically safe work condition.

Many of the more significant changes, though, have happened within Art. 130: the idea of risk assessment and the importance of accurately assessing what hazards to employee health exist when performing tasks in the field; old tables are gone, and new tables with increased usability for the NFPA 70E user have surfaced; and material that lived within the Annex is now incorporated within the document. Let’s break these revisions down, and look at the potential impact they will have on how electrical professionals approach electrical safety.

The hierarchy of risk control methods

The concept of a hierarchy of risk control methods is by no means new. It has been a concept within OSHA and was also in an informational note in previous editions of NFPA 70E, which has provided guidance on how employees are protected from hazards in the workplace. However, for the 2018 cycle, a section was added within Art. 110 for the risk assessment procedure to require preventive and protective measures to be implemented in accordance with the following hierarchy:

  1. Elimination
  2. Substitution
  3. Engineering Controls
  4. Awareness
  5. Administrative Controls
  6. Personal Protective Equipment (PPE)

This requirement comes in the form of Sec. 110.3(H)(3). Again, this is not a new concept, but is new to the requirements of NFPA 70E. The addition of this hierarchy mirrors a shift in the attitude toward electrical safety. For years, electrical contractors across the country have been adopting a “No Live Work” policy. As nice as it might be to dream of a world where there is never energized work being performed, the reality is at times there simply is no other option. Imagine trying to troubleshoot a roof top HVAC unit without being able to check voltage and current levels. It would be difficult, if not impossible, to say the least.

So, what does this mean for risk assessment procedures going forward? Simply put, it means that all other possibilities must be exhausted prior to an employee being exposed to a hazard. In other words, dressing up in an arc flash suit is the absolute last resort for protecting employees from arc flash hazards. This should come as refreshing news, since the tests that arc-rated PPE must pass allow for a 50% probability that the clothing will allow enough thermal energy to pass through and cause a second-degree burn.

The purpose of NFPA 70E is to provide a practical safe working area for employees relative to hazards arising from the use of electricity. With this in mind, it helps to simplify the process of risk assessment and follow the hierarchy of risk control methods. The priority is to de-energize equipment. This eliminates the need to expose employees to electrical hazards because the hazard is no longer present. It should be noted, too, that during the process of establishing an electrically safe work condition, one of the steps includes verifying the absence of voltage; the hazard cannot be considered eliminated until after it has been proven that voltage has been removed and operation of the test instrument has been confirmed. This might mean that an employee would need to dress in appropriate PPE to perform this test because until it has been verified that the hazard is gone, it must be assumed that one still exists. However, even this process has seen new and innovative technology emerge and aims at protecting employees from ever having to be exposed to an assumed potential hazard. Permanently mounted absence of voltage testers are emerging to assist employees in verifying the hazard has been removed, without being exposed to a hazard during the verification process.

The Risk Assessment Procedure might also lead what was previously thought to be “justified” energized work to become unjustified during the planning process. For example, as a matter of preparing for the worst and hoping for the best, often it is necessary to develop an alternative plan just in case an unforeseen and catastrophic event occurs. Think about this for a moment: How would we care for patients in the ICU wing of a hospital if energized work were to cause an unexpected shut down of the system? If a back-up plan can be determined for when the system has an unplanned shutdown, it makes sense to implement this plan first and never expose employees to the hazard. This hierarchy now requires that elimination of the hazard to be the priority, and your well-crafted back-up plan just became the first step in ensuring safe work practices.

Re-organization of Art. 120

Previous editions of NFPA 70E had all the right pieces for establishing an electrically safe work condition, but it needed a little tweaking for all the requirements to fall into the right order. The technical changes within Art. 120 are relatively minor in the grand scheme of things, with the exception of permission to use the aforementioned permanently mounted test device for verification of absence of voltage. However, by re-arranging the order in which tasks are listed in Art. 120, the process for establishing an electrically safe work condition is easier to implement.

Previously, the Article started out with the section on verification of an electrically safe work condition. This was leading to some confusion as users of NFPA 70E were jumping around Art. 120 to find the different requirements they needed (as they were following the steps outlined in Sec. 120.1). With the new arrangement, however, Art. 120 is reorganized to increase usability and to provide a more logical flow with the following section layout:

• Section 120.1 (Lockout/Tagout Program)

• Section 120.2 (Lockout/Tagout Principles)

• Section 120.3 (Lockout/Tagout Equipment)

• Section 120.4 (Lockout/Tagout Procedures)

• Section 120.5 (Achieving an Electrically Safe Work Condition)

Now all the requirements for each of these important topics can be found in one place. In addition to reorganizing the requirements that belong in Art. 120, certain requirements were removed and relocated to other sections of NFPA 70E as appropriate. For example, lockout/tagout training and auditing requirements were moved into Art. 110 under the appropriate sections that deal with training and auditing.

The continued evolution of risk assessment

Assessing the amount of risk of injury or damage to health that an employee will face during any given task can be a monumental undertaking; until only a few cycles ago, it was almost impossible. Then something amazing happened. The evolution of risk assessment, in my opinion, is the number one indicator that a fundamental shift in the safety culture of our industry is taking place. Only a few short years ago, certainly at times throughout my career, the attitude toward performing energized work was cavalier at best. I can remember as an apprentice being asked to perform work in switchgear that was energized. I had no PPE, no justification for performing energized work, and certainly no formal risk assessment procedure. The guidance from my journeyman was simply: “Don’t drop your wrench or touch any of the bus bars over here. This stuff is expensive, and takes a long time to get. And, oh yeah, it will hurt, A LOT!”

Fast forward to today, and the procedures in place would never have allowed a conversation like that to take place. However, only with a significant change in the way our industry views safety can we appropriately and accurately assess the risk associated with given tasks and take the necessary steps to minimize our exposure to hazards. The concept of risk assessment has forced employees and employers to be honest with themselves and with each other about what could happen if a wrench is dropped or
accidental contact is made with energized components. The days of such a “macho” attitude of invincibility have given way to more informed discussions about how bad it could be and whether it is worth the risk.

The latest evolution in the risk assessment arena is a major shift in the approach to minimizing the worker’s exposure to hazards. In earlier editions of the standard, the PPE Category method contained a table that specified whether arc flash PPE was required based upon a list of common tasks. However, with the addition of the hierarchy of risk control methods being included in the requirements, now the appropriate method to protect the worker might not be PPE. In fact, PPE must be the last resort for protection. In addition, there was nothing to specify whether additional measures were required to protect workers from equipment that had undergone an incident energy analysis; many users wanted to use a hybrid of the PPE Category “Yes/No” table and the values determined for incident energy — a practice that NFPA 70E specifically prohibited.

This confusion was discussed at length by the committee, and the result is a new Table 130.5(C). This table now applies to either method employed for arc-flash risk assessment. However, it should be noted that this table no longer tells the user whether arc flash PPE is required. Rather, this new table helps in determining if additional measures are needed to protect workers by specifying whether an arc flash is likely to occur for given tasks. This process works in parallel with the hierarchy of risk control methods as well, which is why the table no longer specifies a need for PPE. Per the hierarchy, PPE is only to be used after the other five methods have been exhausted.

One more important distinction about this table is that it does not end the risk assessment procedure. This table is only an estimate of the likelihood of an arc flash occurring, as opposed to the former table, which specified that for some tasks PPE was not required. The risk assessment procedure can still determine there is a need to take additional steps to protect employees, even though Table 130.5(C) lists the likelihood of an arc flash as a “No.”

Let’s look at the example of performing thermal imaging during a maintenance inspection. Per the table, the process of removing the equipment covers does pose an increased likelihood of causing an arc flash; however, once the covers are removed and the thermography is performed outside the restricted approach boundary, the likelihood of occurrence changes to “No.” But does that mean there is no situation where an arc flash could injure the thermographer?

Let’s consider a motor control center (MCC) with automatic control features. If the covers are off and the motor starters are being operated through automatic means, an arc flash hazard might still exist and must be accounted for in the protection of the worker performing the thermography. Unfortunately, there is no “easy” button when it comes to electrical safety, but being armed with knowledge of how the risk assessment procedure is intended to protect workers will go a long way in reducing loss and injury due to electrical incidents.

An increased emphasis on maintenance

The need for proper maintenance of electrical equipment is not a new idea. However, this is one of those areas where the equipment in question is often an “out of sight, out of mind” situation until it fails. There is even equipment where the common course of action is to “set it and forget it.” Equipment failure is the indication that it needs attention, like a light bulb. The maintenance issue continues to surface through risk assessment procedures; however, it is becoming an ever-increasing cog in the personnel safety wheel. If the safety of employees depends on proper operation of certain electrical components, how can it be known whether equipment will operate if there is no record of maintenance?

In the 2015 edition of NFPA 70E the concept of “Normal Operation of Equipment” was added to justified energized work. This included tasks such as operation of SWD/HID circuit breakers to turn on and off lights in a warehouse or jogging a motor starter in an MCC. Normal operation has very specific conditions that must be met for a normal operating condition to exist. The equipment must meet the requirements outlined in Sec. 130.2(A)(4), including the need to be properly installed and maintained. This thrusts maintenance firmly into the forefront when it comes to what is considered “Normal Operation” of equipment.

In addition to the normal operation requirement, the evolution of the risk assessment procedure is also pushing maintenance to the top of the priority list. After all, if all my assumptions and calculations are based on specific operating parameters of given equipment, it is very important that the equipment work as advertised. The only way to be certain that this will happen is to ensure that equipment has been properly maintained and the maintenance documented. Documentation is crucial to track the history and accurately assess what level of risk the future holds.

Honorable mentions

With so many things going on in the evolution of electrical safety, it becomes difficult to spend meaningful time discussing them all in one place. But there are a few additional changes worth noting:

• Two new steps in establishing an Electrically Safe Work Condition.

• Release stored electrical and mechanical energy.

• PPE conformity assessment

• Annex H PPE table incorporated into the requirements.

• Risk assessment must account for human error.

This is by no means meant to be a complete list of all the changes within the 2018 edition of NFPA 70E. By starting a conversation about some of the more important concepts in electrical safety, we can continue to support the shift in attitude of an entire industry segment. At the end of the day, we are all after the same thing. Everyone wants to go home in one piece. Evolving standard work practices take time and buy in from those affected. Only by spreading this message of a revised electrical safety culture can we ever hope to work in a field where nobody gets a ride in an ambulance due to taking an unjustified risk.

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May
14

What Is Electrical Grounding?

Electrical grounding or “Grounding” originally began as a safety measure used to help prevent people from accidentally coming in contact with electrical hazards. Think of your refrigerator. It is a metal box standing on rubber feet with electricity running in and out of it. You use magnets to hang your child’s latest drawing on the metal exterior. The electricity running from the outlet and through the power cord to the electrical components inside the refrigerator are electrically isolated from the metal exterior or chassis of the refrigerator.

If for some reason the electricity came in contact with the chassis, the rubber feet would prevent the electricity from going anywhere and it would sit waiting for someone to walk up and touch the refrigerator. Once someone touched the refrigerator the electricity would flow from the chassis of the refrigerator and through the unlucky person possibly causing injury.

Grounding is used to protect that person. By connecting a green ground wire from the metal frame of the refrigerator, if the chassis inadvertently becomes charged for any reason, the unwanted electricity will travel through the wire back to your electrical panel, and tripping the circuit-breaker stopping the flow of electricity. Additionally, that wire must be connected to something that is in turn connected to the earth or ground outside. Typically this connection is a grounding electrode, such as a ground rod.
Grounding and Earthing

A typical grounding electrode

The process of electrically connecting to the earth itself is often called “earthing”, particularly in Europe where the term “grounding” is used to describe the above-ground wiring. The term “Grounding” is used in America to discuss both below-grade earthing and above-grade grounding.

While electrical grounding may have originally been considered only as a safety measure, with today’s advances in electronics and technology, electrical grounding has become an essential part of everyday electricity. Computers, televisions, microwave ovens, fluorescent lights and many other electrical devices, generate lots of “electrical noise” that can damage equipment and cause it to work less efficiently. Proper grounding can not only remove this unwanted “noise”, but can even make surge protection devices work better.

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