ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 [2]  All   Go Down

Author Topic: Outdoor GFI and my city  (Read 1170 times)

Tim McCulloch

  • SR Forums
  • Hero Member
  • *
  • Offline Offline
  • Posts: 22187
  • Wichita, Kansas USA
Re: Outdoor GFI and my city
« Reply #10 on: July 19, 2021, 06:27:40 PM »

I have a (temporary) stage setup at an arts center. The city is demanding that ALL outdoor electrical be on GFCIs.

We are a little old school in the lighting department. Inside, they have a breaker panel with with camlock outputs. We run the camlock cables to a dimmer pack. The dimmer pack runs socapex out the door of the building to the stage, and connects to the lights hanging from the roof.

The city has asked if we can get a 100 amp 3 phase GFCI breaker. I've called around. It seems that it doesn't exist, at least for their electrical panel (Square-D).

Is there a way to comply with what they want?

And more complicated probably, is there a document that I can give them from somewhere showing what the "industry standard" is and how they are being overly cautious? I think they kind of just don't understand what we are doing...

Thanks!

Tell the City that it's THEIR issue to provide proper protection of THEIR ELECTRICAL SERVICE and ask that the public utility supervisor speak to the city manager's office.
Logged
"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

Stephen Swaffer

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2475
Re: Outdoor GFI and my city
« Reply #11 on: July 20, 2021, 02:18:46 PM »

That is why I pointed it out that it is not a receptacle.  Code requires it on receptacles-what might get plugged into that receptacle is unknown.  My suspicion is that this was targeted at RV's, at least originally.

As an electrician, I view a load, even a distributed load like a lighting system differently.  Especially, IF it is professionally designed and maintained with assured grounding.

In my experience, administrators-be they government or private-often don't really understand and land on the side of safe over sorry.  Don't get me wrong-I am not suggesting short cutting safety, but I have seen many times where unnecessary pain was cause in the name of safety.  In the long run, that is not productive as the "behind the scenes" work around are often unsafe.
Logged
Steve Swaffer

Brian Jojade

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2091
    • HappyMac Digital Electronics
Re: Outdoor GFI and my city
« Reply #12 on: July 20, 2021, 03:40:43 PM »

Tell the City that it's THEIR issue to provide proper protection of THEIR ELECTRICAL SERVICE and ask that the public utility supervisor speak to the city manager's office.

In a nice way, of course.

Even still, if they decide to put a GFCI on the main feeder for you, and your load trips that GFCI because of the combined leakage, that's going to make for a long show.  Yeah, it may not be YOUR fault directly, but you're the one that will look bad if it doesn't work.
Logged
Brian Jojade

Guy Holt

  • Full Member
  • ***
  • Offline Offline
  • Posts: 130
Re: Outdoor GFI and my city
« Reply #13 on: July 22, 2021, 01:06:58 PM »

Even still, if they decide to put a GFCI on the main feeder for you, and your load trips that GFCI because of the combined leakage, that's going to make for a long show.  Yeah, it may not be YOUR fault directly, but you're the one that will look bad if it doesn't work.

In my experience, arguing over semantics with an inspector is not a winning strategy.  The NEC gives them wide latitude in interpreting the code book. What they say is the Code whether they are right or wrong. Besides, the 2020 Code extends the 100A 3-Phase GFCI requirement to outlets as well as receptacles, so it is a non-starter if they are following the 2020 Code.

In the film industry we have been doing this successfully before it was even required by Code.  The first high amperage multi-phase ground fault protection device was developed by Bender for the production of Titanic (they couldn’t have Leo and Kate get shocked in the water tank, now could they?).

Brian Jojade is right that the combined leakage current over your entire distro will exceed the 5mA trip threshold required by Code – making the Littelfuse 100A GFCI mentioned previously not an option.  In your situation you have two options.  Putting a GFCI dongle at the Soco break-out is not one of them.  GFCIs require constant voltage to operate and so can’t be used on dimmed circuits. Guardian in LA has GFCI boxes (model LG620) with Socos in and out and Bender RCM420 Class A GFCIs inline of each circuit of the Soco (six GFCIs in each box.) They get around the voltage issue by powering the GFCIs with a separate non-dimmed circuit. The problem is that they have to be shipped from LA and are not cheap to rent. The other option is to throw yourself on the mercy of the inspector and show them that you can achieve the same objective (establishing and maintaining effective safety) by using a 3-phase GFPE (which is what I do for film base camps.)

The NEC Section 100 definition of a GFCI is a “Class A device” as specified by UL943. UL943 defines GFCIs as devices having a fixed trip setting of 5mA (+/- 1mA). Even though they can be set-up to offer ground fault protection that meets the UL 943 safety standard at specific current levels, the 3-phase GFPE provided by LifeGuard, Shock Block, and Shock Stop are not technically GFCIs because they offer user adjustable trip thresholds (the Shock Stop 400D is my favorite because it can double as a variable disconnect as well.) Since they do not meet the complete UL943 standard, they technically do not meet the Code requirement for GFCI protection where prescribed. But, as I said at the outset, the Code gives the AHJ a great deal of discretion in how to apply the rules. Section 90.4: Enforcement states:

“… the authority having jurisdiction may waive specific requirements in this Code or permit alternative methods where it is assured that equivalent objectives can be achieved by establishing and maintaining effective safety.”

Absent a better alternative, the use of a GFPE is an easy sell to your AHJ.  To seal the deal, show them a solidly connected EGC with an impedance less than 1Ω and remind them that a low impedance ground is the basis upon which UL943C permits trip thresholds higher than 6mA in industrial GFCIs and is the basis of one of only two exceptions in the Code to Section 210.8(B)(4). According to Section 590.6(B)(2)(a)(1)), in industrial settings, equipment that is not compatible with the 6mA trip threshold of Class A GFCIs may be exempted from the requirement for GFCI protection stipulated in 210.8(B)(4) if the equipment grounding conductor is regularly tested. 

The importance of a low impedance EGC in electrical safety cannot be overstated.  To receive an electrical shock an individual must make contact with a voltage source. Statistically this occurs most often when an internal wire shorts to the case of the equipment they are handling. How do you prevent a shock?  Remove the voltage before anyone can come in contact with it. If, the equipment case or cabinet is solidly bonded all the way back to the source, according to Ohm’s law (V=IR or I=V/R) a ground fault current sufficient to trip the upstream overcurrent device will be generated as soon as it is turned on, removing the voltage before anyone can make contact with it – a simple but effective means of preventing shocks.

With a solidly connected ground, the AHJ should have no problem in this case with waiving the specific requirement in Section 210.8(B)(4) for a Class A GFCI.  After all, GFPE with a trip threshold and a trip time within the UL943 safety standard, and a low impedance ground that will eliminate deadly touch potential, achieves the same objective (establishing and maintaining effective safety) as a Class A GFCI.   

Guy Holt, Gaffer, ScreenLight & Grip                 
Logged

Guy Holt

  • Full Member
  • ***
  • Offline Offline
  • Posts: 130
Re: Outdoor GFI and my city
« Reply #14 on: July 22, 2021, 02:52:39 PM »

I found this doing a very quick search......

https://www.motionlabs.com/gfci-protection-live-performances/


I remember hearing an "interpretation" of the code at one time that more or
less said if the outlets did not have public access GFI's were not needed.
That interpretation may have been complete bunk as well.

IMO, Jim Herrick at Motion Labs is mistaken in his analysis of the requirements for GFCIs contained in the 2020 Code. On more than one occasion he uses the argument that if GFCIs are not explicitly mentioned in a Code Article they are not required. In fact, the opposite is true.

Probably because I authored a series of articles on the NEC for Protocol called “Cracking the Code” a major manufacturer of distribution equipment (who shall remain nameless) reached out to me recently for my take on the 2020 Code revisions pertaining to the use of GFCIs.  They said their customers are “waking up from their Covid 19 stupor to find the Code has changed.’ Where my response is not published anywhere, I have posted it here in its entirety because context is everything when it comes to this subject.

“Dear John Doe,

Unfortunately, there is no simple answer to whether the 2020 NEC section 210.8(B) now requires CLASS A protection for 100A, 60A, 30A 3 phase receptacles of portable distribution equipment. Given the way the Code is structured, it comes down to where power is being used and by whom.

As explained in Section 90.3 Code Arrangement, Chapters 1 thru 4 apply generally to all electrical installation and Chapters 5 thru 7 apply to special occupancies, special equipment, or other special conditions. As clearly stated in the organizational chart of the Code, Chapters 5, 6, & 7 “supplement or modify Chapters 1 through 4.”  So, the first question one must ask when looking at special occupancy chapters is, do they supplement or modify the requirements of Section 210.8 (B). If not explicitly modified in the chapters pertaining to special occupancies, the rules in the first four chapters (pertaining to the sizing of overcurrent protective devices, phase conductors, neutral conductors, equipment grounding conductors, and ground electrode conductors), apply to the special occupancies as well.

For example, the requirements of subsections (C) and (D) of Section 210.23 Branch Circuit Permissible Loads, disallow 40-ampere and larger branch circuits from serving 5k and 10K stage lighting fixtures. Section 210.23(C) permits 40- and 50-Ampere branch circuits to supply only cooking appliances that are fastened in place and fixed lighting units - not portable ones. While Section 210.23(D) states that branch circuits larger than 50 amperes shall supply only “non-lighting outlet loads.” Where these two sections appear in Article 210 Branch Circuits, they apply generally and therefore preclude the use of portable 5k and 10K fixtures anywhere.

Since portable 5k and 10K fixtures are commonplace in motion picture stage lighting, Article 530 excludes motion picture and television studios from this general requirement. The pertinent section of Article 530 is Section 530.23 Branch Circuits and reads as follows: “A branch circuit of any size supplying one or more receptacles shall be permitted to supply stage set lighting loads.’ The purpose of 530.23 is to exclude motion picture and television studios from the requirements of Section 210.23 relating to connector rating and branch-circuit loading (subsections (C) and (D)). The significance of this for your customers is that, given Code structure, the general requirements relating to GFCI protection found in Article 210.8 (B) apply to the special occupancy they work in unless explicitly excluded in the Article that pertains to that special occupancy.  So, to answer your question, we must survey the relevant special occupancies to see if they exclude or modify the GFCI requirement of NEC section 210.8(B)

Article 520: Theatres, Audience Areas of Motion Picture and Television Studios, Performance Areas, and Similar Locations

The pertinent section of Article 520 is 520.9, Branch Circuits which states “The requirements in 210.8(B), other than 210.8(B)(4), shall apply.” Before we get too alarmed at government regulatory over-reach, let’s look at where Sections 210.8(B) requires the use of GFCIs. They are required in bathrooms (Subsection (B)(1)), kitchens or areas with a sink (B)(2), rooftops (B)(3)), receptacles installed within 6ft of a sink (B)(5),  indoor damp and wet locations (B)(6), locker rooms with associated showering facilities (Subsection (B)(7)), garages and similar areas (Subsection (B)(8)), crawl spaces (B)(9), laundry areas (B)(11), bathtub and shower stalls (B)(12), and the unfinished areas of basements of “a building or structure, indoor or outdoor, designed or used for presentation, dramatic, musical, motion picture projections, or similar purposes and to specific audience seating areas within motion picture or television studios” (Section 520.1 Scope). In short, not on-stage lighting and special effects.  Your theatre customers don’t have much to be concerned about unless a set includes a kitchen or bathroom with working plumbing. And, of course, receptacles outdoors are excluded as well.
As a side note: the exceptions in 210.8(B)(4) for branch circuits dedicated to de-icing equipment (Exception 1) and branch circuits loaded under the supervision of qualified personnel (Exception 2) that you have identified as a possible “golden ticket” do not apply here since they pertain only to outdoor receptacles which are already excluded from the GFCI requirement of Section 210.8(B) by Section 520.9.

Article 525: Carnivals, Circuses, Fairs, and Similar Events

This article covers the installation of portable wiring and equipment for carnivals, circuses, fairs, and similar functions, including wiring in or on all structures (Section 525.1 Scope.) Section 525.3 Other Articles, states explicitly “wherever the requirements of other articles of this Code and Article 525 differ, the requirements of Article 525 shall apply to the portable wiring and equipment.” (Section 525.3(A))

There are two relevant sections in Article 525 that modify the requirements of Section 210.8(B). The first is Section 525.23(A), Ground-Fault Circuit-Interrupter (GFCI) Protection which states:

“In addition to the requirements of 210.8(B), GFCI protection for personnel shall be provided for the following:
(1) All 125v, single phase, 15 and 20-ampere non-locking-type receptacles used for disassembly and reasonably or readily accessible to the general public.
(2) Equipment that is readily accessible to the general public and supplied from a 125-volt, single-phase, 15- or 20-ampere branch circuit.”

The second is Section 525.23(B) which states:

“Receptacles that are not accessible from grade level and that only facilitate quick disconnecting and reconnection of electrical equipment shall not be required to be provided with GFCI protection….”

Note that, with the exception of excluding receptacles not accessible from grade level (i.e. not accessible to the general public) and egress lighting, Article 525 does not exempt these special occupancies from the requirements of Section 210.8(B), especially the requirement for GFCIs outdoors. Instead, Section 525.23(A) adds any 125v, single phase, 15 and 20-ampere non-locking-type receptacle readily accessible to the general public regardless of its location. Note this section supplements rather than modifies the requirements contained in Section 210 (B)(4).

Where Article 525 does not exempt outdoor receptacles, the users of your products for carnivals, circuses, fairs, and similar functions must provide GFCI protection as required by Section 210.8(B): on outdoor receptacles of 125-volt through 250-volts “… supplied by single-phase branch circuits rated 150 volts or less to ground, 50 amperes or less” (Section 210.8(B)).  And where Article 525 has no explicit exemption for distribution equipment handled by qualified personnel, GFCIs are required on “all receptacles supplied by three-phase branch circuits rated 150 volts or less to ground, 100 amperes or less” (Section 210.8(B)).

This last requirement of 210.8(B)(4) creates an interesting dilemma for users of distros with 100A-120/208V 5 wire Pin & Sleeve inputs. Since the requirement for GFCI protection on receptacles supplied by three-phase branch circuits rated 150 volts or less to ground, 100 amperes or less appears only in Article 210 which “provides the general requirements for branch circuits” (Section 210.1 Scope), if this style of distro is used downstream of you’re a 4 Way 100A Pin & Sleeve box, the 100A cable serves as branch circuit wiring and Class A GFCI protection is required on the four 100A 3-phase branch circuits.

An analysis for Disney Land, conducted by an electrical engineering firm, concluded that Section 210.8(B)(4) requires Class A devices on 3-phase pin and sleeve receptacles all the way up to and including 60A and 100A receptacles. In their analysis, there are “no applicable exceptions or “outs” from the requirement based on the current Code language for branch circuit wiring.” If, however, distros with 100A-120/208V 5 wire Pin & Sleeve inputs are connected directly to a power supply (either a small 25kVA gen-set or transformer secondary), the 100A cable acts as feeder wiring and Class A GFCI protection is not required.

Article 545: Manufactured Buildings and Relocatable Structures

Since this article defines trailer mounted studio dressing rooms as relocatable structures (Section 545.2, Definitions), Article 545 applies to the basecamps of motion picture productions. There are two relevant sections in Article 545. The first, Section 545.28, pertains to the relocatable structure itself and states: “In addition to the requirements of 210.8(B), all receptacle outlets installed in compartments accessible from outside the relocatable structure shall have GFCI protection for personnel.” Which means the 50A RV receptacles of basecamp trailers that are used to patch between its on-board generator and “shore power” are required to have GFCI protection because they are accessible from outside the trailer.

The second, Article 545.22 (A) Feeder, pertains to the power supplied to relocatable structures. An Informational Note in this section states: “for temporary installations of feeder conductors, see Article 590.” The provisions of Article 590 require GFCI protection in temporary electric power and lighting installations (590.1 Scope). But unlike the articles we have discussed thus far, Article 590 also offers an acceptable alternative to the use of GFCIs: Assured Equipment Grounding Conductor Programs (AEGCP). The rationale behind an AEGCP is that frequent and regular inspection and testing of all equipment grounding conductors, receptacles and attachment plugs by personnel trained in electrical hazards (i.e. ¬¬qualified personnel), will assure that the continuity of the Equipment Grounding Conductor (EGC) is maintained and that a low-impedance grounding path will protect workers sufficiently against the hazards of electrical shock by reducing deadly touch potentials and facilitating the operation of over-current devices.

Unfortunately, an AEGCP is not an option for a basecamp generator operator.  Article 590.6(A) and (B), are quite explicit that the use of an AEGCPs is permitted only for receptacles in “industrial establishments” used to “supply temporary power to equipment used by personnel during construction, remodeling, maintenance, repair, or demolition of buildings, structures, or equipment, or similar activities.” (Section 590.6).  Since the distribution of power to basecamp trailers does not fit this description, Article 590 does not remove the requirement for GFCI protection for outdoor receptacles of “125-volt through 250-volt receptacles supplied by single-phase branch circuits rated 150 volts or less to ground, 50 amperes or less, and all receptacles supplied by three-phase branch circuits rated 150 volts or less to ground, 100 amperes or less” (Section 210.8(B)) in basecamp distribution systems.

Article 530: Motion Picture and Television Studios and Similar Locations

The pertinent section of Article 530 is 530.23, Branch Circuits which states “the requirements in 210.8(B), other than 210.8(B)(4), shall apply.”  This explicit exclusion of outdoor receptacles would be good news if not for the fact that Article 530, is widely interpreted by AHJs outside California to mean that it does not pertain to location filming. Section 530.2 defines a “Motion Picture Studio” as
“A building or group of buildings and other structures designed, constructed, or permanently altered for use by the entertainment industry for the purpose of motion picture or television production.”
And a “Shooting Location” as  “A place outside a motion picture studio where a production or part of it is filmed or recorded.”

So, by definition they are not the same occupancy. The NEC Handbook makes this distinction even more explicit when it describes the “Similar Locations” of Article 530’s title as “... those locations presenting special hazards, that is, temporary structures constructed of wood or other combustible material....”  Many AHJs take this to mean that the exemption to Section 210.8(B)(4) permitted by Article 530.23 does not extend outside the confines of a stage. And, since there is no special occupancy chapter for shooting locations, the requirement for GFCIs on outdoor receptacles contained in Section 210.8(B)(4) apply to location filming by default. Given the ramifications, Code Panel 15 (which consists of mostly entertainment industry representatives), has proposed major revisions to Article 530 for the next 2023 Code cycle that will, if adopted, significantly modify the Section 210.8(B)(4) requirement for GFCI protection outdoors.

Typically, revisions to Code articles consist of, either tweaks to existing language to make the intent of a passage clearer, or the addition of new passages required by evolving technologies.  To resolve a number of issues, Code Panel 15 is instead proposing to replace Article 530 in its entirety.  The scope of the new article covers ”motion picture and television production in facilities and locations …“ (new Section 530.1,Scope), as well as base-camp (new Section 530.45 Portable Trailers and Production Vehicles). It also requires “distribution systems, generators, battery systems, and other power-sources, … be deployed, energized, and while energized, operated and continuously supervised by trained, qualified, and employer-authorized personnel” (new Section 530.4 Supervision by Qualified Personnel).

The structure of the proposed new Article 530 makes a distinction between Production Areas (Part II) and Support Areas (Part III) and the GFCI requirements for each. Section 530.11 Branch Circuits states “the requirements of 210.8(B), other than 210.8(B)(4), shall apply” in production areas, thereby eliminating the requirement for GFCI protection outdoors for small cord set lighting. Whereas the new Section 530.44 requires GFCI protection in support areas in “125-volt, single-phase, 15- and 20-ampere non-locking type receptacles used for disassembly and reassembly or readily accessible to unqualified personnel.”  In other words, Section 530.11 exempts outdoor 15- and 20-ampere receptacles used by qualified personnel in production areas, while there is no such exemption for 15A and 20A receptacles used by unqualified personnel in support areas - 15A and 20A receptacles used by qualified personnel in support areas are exempted (New Section 530.44). Unfortunately, it will be 2023 at the earliest before the revisions will be adopted in any state (if they are adopted at all), which means that GFCI protection must now be provided for outdoor receptacles of 50-amperes or less on location and in basecamp as presently stipulated by Section 210.8(B)(4).

As you can see, given the way the Code is structured, whether a GFCI is required on a receptacle comes down to where power is being used and by whom. If things weren’t complicated enough, the Code’s three-year cycle and the power it invests in the local authority having jurisdiction (AHJ) further complicates this issue.

Further Complications

According to the NFPA website, the NEC has been “adopted in all 50 states.” That statement glosses over the complex reality of local building codes, which may or may not line up with state actions. A more accurate statement would be the NEC has been “adopted in all 50 states, but not by all 50 states.” Not every state has compliance with the NEC written into its codes or regulations. For example, as of January 2020, Arizona, Mississippi, and Missouri did not have state-wide adoption of any version of the NEC, and only the state of Massachusetts had adopted the most recent version of the Code.
 
The patchwork of codes across the country is in part due to the Code investing authority for code enforcement to a local “Authority Having Jurisdiction” (AHJ). In Section 90.4 Enforcement the Code states:
“... The authority having jurisdiction for enforcement of the Code has the responsibility for making interpretations of the rules, for deciding on the approval of equipment and materials, and for granting the special permission contemplated in a number of the rules.”

Who is this “authority having jurisdiction” that the Code invests with such power? The NEC definition isn’t much help. In fact, in an Informational Note that accompanies the NEC definition, it states: “The phrase ‘authority having jurisdiction,’ or its acronym AHJ, is used in NFPA documents in a broad manner, since jurisdictions and approval agencies vary, as do their responsibilities.” The Article 100 informational note goes on to state:

“Where public safety is primary, the authority having jurisdiction may be a federal, state, local, or other regional department or individual such as a fire chief; fire marshal; chief of a fire prevention bureau, labor department, or health department; building official; electrical inspector; or others having statutory authority. For insurance purposes, an insurance inspection department, rating bureau, or other insurance company representative may be the authority having jurisdiction. In many circumstances, the property owner or his or her designated agent assumes the role of the authority having jurisdiction; at government installations, the commanding officer or departmental official may be the authority having jurisdiction.”

Where approval agencies vary widely, a patchwork of rules and regulations has developed across the country. States with state-wide licensing requirements typically have an electrical or licensing board with the power to give examinations and issue licenses. Some states have no state-wide licensing requirements, leaving this matter entirely to local jurisdiction. Some states exempt certain types of work or classes of installations from electrical code compliance, inspection, or licensing requirements. Other states amend, alter, or reject the NEC in lieu of regional regulations as voted on by local governing bodies. So, where does that leave your customers? Having to navigate a patchwork of code permutations and a variety of AHJs. Depending on where the work is taking place, the AHJ may be the local city electrical inspector, the fire marshal, or even a studio’s safety officer.

For example, as the first state in the nation to adopt the 2020 Code, Massachusetts now requires GFCIs on outdoor set lighting of 150 V or less, and 50 A or less (Section 210.8 (B)(4)). Whereas the County of Los Angeles exempts outdoor sets from the requirement for ground fault protection with GFCIs. How two AHJs, on opposite sides of the country, can come to opposing positions says a lot about the nature of the Code. Let’s explore how it came to this, its ramifications for the distribution of power on set, and what we can do about it.

The Massachusetts Board of Electrical Examiners defines filming locations as a separate occupancy than motion picture and television studios and so does not extend the Section 530.23 GFCI outdoor exemption to location productions. To accommodate a local industry, LA County location permits temporarily change the occupancy of a filming location to a motion picture studio. This simple provision accommodates a local industry while keeping the Code in force generally. This is just one example of many across the country, of an AHJ modifying the Code to suit the needs of a local industry. So, despite its authoritative position and having “National” in its title, NEC standards are merely templates local governments use to create and enforce their own electrical code that meets their own needs. Which raises the question: if the proposed 2023 revision of Article 530 is adopted as part of the 2023 Code, will it also be adopted by local municipalities as well? Based on precedent it is not likely to be adopted in Massachusetts.

Even if the proposed 530 exemption is adopted by the NEC, it most likely will not be adopted in the state of Massachusetts. The basis for the exemption to Section 210.8(B)(4) proposed by Code Panel 15, the “Qualified Person” argument, is the same as has been used in the past for the 400% rule (Section 530.18(A). As you know it goes something like this: set lighting is planned in advance, and the loads on each circuit and on each phase of power is closely monitored. Where loads are not casually connected, as they might be in a typical general-use situation, care is taken by qualified personnel to ensure that circuits are not overloaded. Massachusetts has yet to adopt the 400% rule of 530.18(A) even though it has probably been a part of Article 530 from its inception. Why would the MA Board of Electrical Examiners grant an exemption to a requirement pertaining to life safety when they won’t grant one based upon the same premise (use by qualified personnel) pertaining to equipment safety? If anything, we will see a continued expansion of GFCI requirements. The 2020 Code added 3-phase 100A/120V receptacles. It is only a matter of time before 3-phase 400A/120V Camlok style receptacles are added now that the technology exists.

What we can do:

Option 1: Ignore the issue

Some electricians here say we should just lay low until the revised Article 530 is adopted in 2023. I don’t agree. A lot can happen in two years and the changes could not be adopted. In my opinion, Code Panel 15 is fighting an uphill battle. The “Qualified Person” argument is weak and has been losing ground in other industries for the last several code revision cycles.

Prior to 1996, the NEC permitted either the use of an Assured Equipment Grounding Conductor Program (AEGCP) or the use of GFCI protection for all 125-volt, single-phase, 15-, 20-, and 30-Ampere receptacles and outlets on construction sites. In the 1996 rendition of the Code, two significant changes occurred in Section 305.6, "Ground-Fault Protection for Personnel." First, the scope of the GFCI requirements was greatly expanded by removing the limitation to construction sites only.  Prior to the 1996 NEC, GFCIs were required only on construction sites. The 1996 NEC removed this limitation and expanded the scope of the GFCI provision to include all "temporary wiring installations utilized to supply temporary power to equipment used by personnel during construction, remodeling, maintenance, repair, or demolition of buildings, structures, equipment, or similar activities "

The second significant change was a corresponding restriction on the use of AEGCPs. Prior to the 1996 Code, either the use of a GFCI or adherence to a AEGCP would meet the requirements of this section. In the 1996 NEC, the use of an AEGCP was strictly limited to receptacles and outlets other than 15- and 20-ampere, 125-volt. Subsequent revisions to the Code continued to restrict the use of AEGCPs and expand the scope of GFCI protection to include first 30-ampere receptacles and finally 50-ampere receptacles. The use of an AEGCP in lieu of GFCIs is now restricted to only remodeling/construction in industrial establishments (no longer permitted in new construction) and only when equipment is not compatible with GFCIs.  All of our equipment, with the possible exception of dimmer racks, is compatible with current GFCI technology.  And what Code Panel 15 is proposing is not even as rigorous as an AEGCP.  An AEGCP requires periodic testing and rigorous record keeping – none of which is required in the proposed Article 530. It is a losing argument. The tide is against it.

If your customers wait for the proposed new Article 530 to go into effect, they could be waiting a very long time.  Given the rate at which municipalities across the country revise their municipal codes it could be many years before the revised Article 530 is adopted universally across the country. For example, as of January 2020, Kansas, Illinois, and Indiana were still operating under the 2008 version of the NEC.

Option 2: Do what other industries have done

The significant changes to the 2017 NEC had a major effect on the marina industry.  The odyssey for ground-fault protection (GFP) of marine equipment began with the addition of Sec. 555.3 in the 2011 NEC. This section called for “ground-fault protection” on the main overcurrent protective device (OCPD) servicing a marina or boatyard. This “ground-fault protection” was to have a maximum 100mA capacity. In lieu of this “ground-fault protection” on the main, individual ground-fault circuit interrupter (GFCI) protection on each branch circuit or feeder was permitted. But confusion existed with this provision before the ink dried on the paper, as this new requirement was aimed at “protection for personnel” not ground-fault protection (GFP) for equipment. Yet the title and the Code language referenced “ground-fault protection.”

For the 2017 NEC, this maximum 100mA capacity was reduced to 30mA. Once this 30mA maximum GFP requirement went into practical application it proved to be unreliable. Through a cumulative effect, it did not take but a few boats leaking current into the water around a marina before the 30mA level was exceeded. This 30mA maximum required GFP requirement virtually shut down new construction of marinas and boatyards in jurisdictions enforcing the 2017 NEC. Desperately in need of relief from this 30mA maximum GFP requirement, the marina industry trade group petitioned the NFPA to change these requirements. The NFPA listened and the changes were made by a Tentative Interim Amendment (TIA).

TIAs are the only means of changing Code requirements between the three-year code revision cycle and are issued by the NFPA for the purpose of adding to, changing, and/or clarifying existing code language between the period of standard publications. When a TIA is approved and published, it amends the current code standard and becomes new code. We can petition for a TIA to remove the 210.8(B) requirement for GFCI protection of single-phase 50A receptacles and three-phase 100A receptacles.

Option 3: Work with the local AHJ on a case-by-case basis

The Code gives a local AHJ a great deal of discretion in how to apply NEC regulations. Section 90.4: Enforcement states:

“… the authority having jurisdiction may waive specific requirements in this Code or permit alternative methods where it is assured that equivalent objectives can be achieved by establishing and maintaining effective safety.”

Absent a better alternative, the use of Ground-Fault Protection Equipment (GFPE), like the Shock Stop 400D with Bender RCM420, that conforms to UL1053 may be an easy sell to a local AHJ.  To seal the deal, show them a solidly connected EGC with an impedance less than 1Ω and remind them that it is the basis upon which UL943C permits trip thresholds of 20mA for protection of personnel and is the basis of the only alternative to GFCI protection offered by the Code. According to Section 590.6(B)(2)(a)(1)), in industrial settings, equipment that is not compatible with the 6mA trip threshold of Class A GFCIs may be exempted from the requirement for GFCI protection stipulated in 210.8(B) if the equipment grounding conductor is regularly tested for continuity.
 
The importance of a low impedance Equipment Grounding Conductor in electrical safety cannot be overstated.  To receive an electrical shock an individual must make contact with a voltage source. Statistically this occurs most often when an internal wire shorts to the case of the equipment they are handling. How do you prevent a shock?  Remove the voltage before anyone can come in contact with it. If, the equipment case or cabinet is solidly bonded all the way back to the source, according to Ohm’s law (V=IR or I=V/R) a ground fault current sufficient to trip the upstream overcurrent device will be generated as soon as it is turned on, removing the voltage before anyone can make contact with it – a simple but effective means of preventing shocks.

With a solidly connected ground, the AHJ should have no problem with waiving the specific requirement in Section 210.8(B)(4) for a Class A GFCI.  After all, the Shock Stop 400D set for a trip threshold and a trip time within the UL943 safety standard, and a low impedance ground that will eliminate deadly touch potential and generate, according to Ohm’s Law (I=V/R), sufficient fault current to trip the upstream breaker almost instantaneously, achieves the same objective (establishing and maintaining effective safety) as a Class A GFCI.”                     




Logged

Brian Jojade

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2091
    • HappyMac Digital Electronics
Re: Outdoor GFI and my city
« Reply #15 on: July 22, 2021, 07:37:20 PM »

In my experience, arguing over semantics with an inspector is not a winning strategy. 

Yup.  Arguing won't work.  Putting together a valid case scenario and convincing them of the safety could work, but their word is the last, so if you don't win the argument, then all you need to do is comply somehow.

Clearly, having this sorted before game day is critical.
Logged
Brian Jojade

Guy Holt

  • Full Member
  • ***
  • Offline Offline
  • Posts: 130
Re: Outdoor GFI and my city
« Reply #16 on: July 26, 2021, 01:15:13 PM »

Oh, and crown iTech amps? Yeah, those trip GFCI's automatically, so those would be out of the question too.

In motion picture production we have a number of lights that also leak so much residual current that they also automatically trip a standard GFCI. The thing about residual current is that it is, for the most, at high frequencies. So that these lights do not nuisance trip their GFCIs, the manufacturers of film style GFCIs (Bender, Littelfuse, & Shock Stop) incorporate low band pass filtration and more forgiving trip curves.

The UL943 trip curve is a lot more forgiving than your standard GFCI.  Standard GFCIs are very aggressive. Instead of using the UL943 curve they use a more aggressive response that is lower and faster than that required by UL943 (typically 250ms at 6mA where UL943 permits 5.59 seconds at 6mA.) The more aggressive response of these GFCIs is permissible because the UL943 standard is the absolute highest current vs. time response allowed but it is not mandatory. That is, a device will fail UL testing if it responds slower than the standard requires; but will pass if the response time is less than the standard requires, even if it is a lot less. While the more aggressive trip curve of most GFCIs does not generally pose a problem in the one-tool- per-circuit application for which they are designed, it has proven to be a problem in electrically noisy environments like motion picture production.

Baked into equipment, high frequency leakage current cannot be eliminated, but it can be filtered. Since it poses no shock hazard, UL 943 permits manufacturers to employ high frequency filters, called band pass filters, to filter out frequencies above
100Hz. Blind to high frequency leakage currents, GFCIs with band pass filters are less prone to nuisance tripping in noisy environments; but band pass filters are expensive and since they are not required by UL943, most manufacturers of GFCIs do not incorporate them into their products. Fortunately, Bender, Littelfuse, and Shock Stop incorporate band pass filters into most of their products to guard against nuisance tripping by the high frequency leakage currents generated by HMIs, Kinos, and LEDs.

These manufacturers also employ sophisticated microprocessors to obtain trip curves that more closely approximate that of UL943. While they don’t take advantage of the maximum allowable response time of UL943, (the typical response time at 6mA is 900ms) it is far greater than most GFCIs which are typically 250ms at 6mA. As a result, film GFCIs, like Shock Blocks, LifeGuards, and Shock Stops, are far more accommodating of transient switch-on surges (while ensuring adequately safe response time) than are GFCIs that trip almost instantaneously at 6mA. Unfortunately, these manufacturers do not employ these features in their 15- or 20A GFCIs.

Fortunately, there is another option. Where 15- and 20A circuits must be GFCI protected, NEC Section 215.9 of the Code permits the feeder to be GFCI protected instead. Section 215.9 reads as follows:
 
“Feeders shall be permitted to be protected by a ground fault circuit interrupter installed in a readily accessible location in lieu of the provisions for such interrupters as specified in 210.8 and 590.6(A).”

Since this section prescriptively identifies feeder GFCI protection “in lieu of” that required in 210.8, it permits the use of film GFCIs (like the Shock Block SB100, LifeGuard LG100, and Shock Stop 60-100), with breakout boxes to satisfy the Code's requirement for GFCI protection on all single-phase branch circuits of 150V to ground or less, rated 50 amps or less. With a more accommodating trip curve and high frequency filtration, it is better to use a film GFCI just upstream of a breakout  box, then to use individual GFCI dongles on each 20A circuit of the box.

Guy Holt, Gaffer, ScreenLight & Grip

Logged

Brian Jojade

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2091
    • HappyMac Digital Electronics
Re: Outdoor GFI and my city
« Reply #17 on: July 26, 2021, 02:17:02 PM »

That's awesome info Guy! 

Sounds like a perfect solution for this scenario.  But then I searched for the price for the equipment you listed.  Ouch.  Yeah, not something I can just causally throw into a gig bag!  Good stuff to have, for sure.  But if the city demands it, that would definitely have to be a line item up charge.
Logged
Brian Jojade

Guy Holt

  • Full Member
  • ***
  • Offline Offline
  • Posts: 130
Re: Outdoor GFI and my city
« Reply #18 on: July 26, 2021, 03:03:18 PM »

That's awesome info Guy! 

Sounds like a perfect solution for this scenario.  But then I searched for the price for the equipment you listed.  Ouch.  Yeah, not something I can just causally throw into a gig bag!

You can only rent the film versions of the Bender and Littelfuse GFCIs. The Shock Stops are for sale or rent. (Full disclosure: we are a dealer for Shock Stops).

Guy Holt, Gaffer, ScreenLight & Grip
Logged

ProSoundWeb Community

Re: Outdoor GFI and my city
« Reply #18 on: July 26, 2021, 03:03:18 PM »


Pages: 1 [2]  All   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.067 seconds with 25 queries.