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Sole Connections

Posted By Keith Lofland, Monday, September 16, 2013

Question: At 250.66(A) and (B), the Code refers to a "sole connection to the grounding electrode.” Please explain what sole connection means; and is the term sole connection defined anywhere in the NEC? PM

Answer: The words "sole” or "solely” appear many times throughout the NEC, but are not defined in Article 100 or in the ".2” sections of individual chapters. The dictionary defines it as an adjective that means "only”; in this situation it is the only connection to the grounding electrode system. Synonyms that show up under a word search are: only, solitary, single, individual, singular, lone, one and only, and exclusive.

This term sole connection is referring to the only connection to the actual grounding electrode itself, and not necessarily a sole or single ground rod. Using the ground rod scenario as an example, if the singular grounding electrode in question consists of two ground rods (one rod supplementing the other), the grounding electrode conductor and the bonding jumper to the second ground rod would be considered the sole connection to this grounding electrode system.

The sole connection clarification was made crystal clear by action taken by code-making panel 5 for the 2014 NEC. The revised language at 250.66(A) and (B) is an attempt to clarify the sole connection sizing provisions for grounding electrode conductors to rod, pipe, plate, and concrete-encased electrodes. The plural language added at 250.66(A) and (B) makes it clear that the sole connection provisions are still relevant, even if more than one of these types of electrodes are installed or are present at a building or structure. As an example, let’s say a single ground rod was installed to supplement a metal underground water piping system that qualified as a grounding electrode [3.0 m (10 ft) or more in contact with the earth]. The ungrounded service-entrance conductors involved are sized at 4/0 AWG copper, which would require a 2 AWG copper grounding electrode conductor. Installing a 2 AWG copper grounding electrode conductor from the service disconnecting means to the metal water piping system would be in order. Section 250.66(A) would permit a 6 AWG copper grounding electrode conductor from the service disconnecting means to the ground rod, or a 6 AWG copper grounding electrode conductor from the metal water piping system to the ground rod, as this 6 AWG copper grounding electrode conductor would be the sole connection to the ground rod. However, using this same scenario, with the two ground rods involved connected together with a bonding jumper [as required in 250.53(A)(2)], has caused some confusion as to whether or not the connection to the first ground rod is now the sole connection, since both a grounding electrode conductor and a bonding jumper are now connected to this first ground rod. The plural language and revised text at both 250.66(A) and (B) should make it clear that the Code considers these two ground rods to be one electrode as far as the sole connection sizing provisions are concerned, and 6 AWG copper conductor could be used at both ground rods.

This revision should clarify that if a grounding electrode conductor is installed to multiple concrete-encased electrodes connected together with a bonding jumper(s), the maximum size grounding electrode conductor to the first concrete-encased electrode or any bonding jumper(s) between the multiple concrete-encased electrodes is not required to be larger than a 4 AWG copper conductor.

— L. Keith Lofland

IAEI Director of Education

Tags:  Focus on the Code  September-October 2013 

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Are there any provisions in the NEC that address the de-energizing of rooftop photovoltaic (PV) wiring in an emergency situation for first responder emergency personnel?

Posted By James Rogers, Friday, April 26, 2013

Question

Are there any provisions in the NEC that address the de-energizing of rooftop photovoltaic (PV) wiring in an emergency situation for first responder emergency personnel? JC

Answer

This answer will be solely in reference to the National Electrical Code (NEC) as there are many local requirements across the country that attempt to address this issue.

Let’s begin with de-energizing. It is well understood that when electrical circuits and equipment are de-energized, they are disconnected from a source of power utilizing a disconnecting means. Using this analogy, your question could be rephrased to inquire if there is a requirement for a disconnecting means for PV circuits; that direct answer is yes.

The language found in the 2011 NEC at 690.14(C)(1) which — states, "The photovoltaic disconnecting means shall be installed at a readily accessible location either on the outside of a building or structure or inside nearest the point of entrance of the system conductors” — first appeared in the 2002 edition of the NEC. When you examine this language, it closely resembles the requirements for service or service disconnecting means. That is predominately due to the fact that many people think of PV systems as being the same as a service. However, they are, in fact, dramatically different from a service as they are a finite power source; whereas, a service is considered infinite for most system design issues. That being said, the design considerations for a disconnecting means required for a service and that required for a PV system are different. The major concern for a service is infinite fault current, and the major concern for a PV system is the ability to extinguish a direct current (dc) arc.

The 2005 NEC added an exception to the disconnecting means requirement found in 690.14(C)(1). This exception referenced 690.31 and allowed the disconnecting means to be located anywhere in the building, provided the PV conductors were installed in metal raceways. You can see as you follow this that the requirement was really focused on the ability to isolate the PV conductors from the other portions of the electrical system and not on the safety of emergency responders. In an effort to enhance some of the basic safety concerns expressed by the fire service in particular, requirements have been added to adequately label the wiring methods that contain these PV conductors so that properly trained emergency response personnel will know that these conductors are more than likely energized.

As you can see, there is not, and never has been, a requirement for rooftop disconnects to assure that the energized conductors could not leave the array area once the disconnect was opened. In 2014 NEC, there will be a new requirement located at 690.12 for an emergency shutdown procedure. Once activated, this emergency shutdown procedure will use electronics to limit the voltage output at the string or module level to not more than 80 volts. However, that voltage may actually decrease to 50 volts when everything in the 2014 NEC process plays out. This requirement still needs some refinement in areas such as who initiates the procedure and how is the procedure initiated. This is the closest approach to totally disconnecting the output of a rooftop system for emergency responders that has ever been made. This requirement was added in response to the work performed by a special committee established by the NFPA NEC Technical Correlating Committee to examine the safety of emergency responders when they respond to buildings that have PV installations.

James J. Rogers
IAEI Representative, CMP-4

Tags:  Focus on the Code  May-June 2013 

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What’s Happening to Table 310.15(B)(7)?

Posted By John Stacey, Friday, April 26, 2013

Question

In the 2011 NEC, does Table 310.15(B)(7) override any ampacity adjustment factors, such as temperature correction factors, or do any ampacity adjustment factors render Table 310.15(B)(7) noncompliant?

Answer

No and No. Is there a Table 310.15(B)(7) in the 2014 NEC? No.

In the 2014 NEC, you will find that the table is gone; but don’t throw it away yet! The new language will allow the size of the conductors to be the same as in the 2011 NEC, unless correction or adjustment factors are required. Certain wiring methods have additional limitations, such as an SE cable used as a feeder running through insulation, so check the article that applies to the wiring method being used.

There were several proposals and comments in the 2014 NEC revision cycle to delete the table and the text entirely; there were some to fix the confusing wording; and there were many concerns expressed about misuse of the table. The correction or adjustment factors were not being used, and there was really no clear way to apply correction or adjustment factors since Table 310.15(B)(7) is based on service and feeder ratings, not conductor temperature ratings. The table only listed the conductor size with no regard for the temperature rating of the conductor, ambient temperature, the number of current-carrying conductors or other installation factors.

The most commonly used wiring type for services and feeders to individual dwelling units are SE cable (SER or SEU). For services, SE cable is allowed to be used at its listed rating of 75°C. For interior branch circuits and feeders, Section 338.10(B)(4)(a) limits SE cable run through insulation to be limited to its ampacity in the 60°C column of Table 310.15(B)(16). Note that Section 310.15(A)(2) Exception allows up to 10 feet or 10% (whichever is less) to run through insulation without limiting the SE cable to 60°C. This applies to other wiring methods as well; if less than 10 feet or 10% runs through an area of lower ampacity, it is acceptable to use the higher ampacity for the entire run.

New Language.

The new 2014 NEC language states:

310.15(B)(7) For one-family dwellings and the individual dwelling units of two-family and multifamily dwellings, service and feeder conductors supplied by a single-phase, 120/240-volt system shall be permitted be sized in accordance with 310.15(B)(7)(a) through (d).

(a) For a service rated 100 through 400 amperes, the service conductors supplying the entire load associated with a one-family dwelling or the service conductors supplying the entire load associated with an individual dwelling unit in a two-family or multifamily dwelling shall be permitted to have an ampacity not less than 83% of the service rating.

(b) For a feeder rated 100 through 400 amperes, the feeder conductors supplying the entire load associated with a one-family dwelling or the feeder conductors supplying the entire load associated with an individual dwelling unit in a two-family or multifamily dwelling shall be permitted to have an ampacity not less than 83% of the feeder rating.

(c) In no case shall a feeder for an individual dwelling unit be required to have an ampacity greater than that of its 310.15(B)(7)(a) or (b) conductors.

(d) Grounded conductors shall be permitted to be sized smaller than the ungrounded conductors provided the requirements of 220.61 and 230.42 for service conductors or the requirements of 215.2 and 220.61 for feeder conductors are met.

Informational Note No. 1: It is possible that the conductor ampacity will require other correction or adjustment factors applicable to the conductor installation.

Informational Note No. 2: See example in Annex D.

This code allowance is still limited to individual dwelling units of one-family, two-family and multifamily dwellings. It is only allowed for 120/240-volt systems sized between 100 and 400 amperes. Any other systems (such as 208Y/120 volt) are not allowed to use this section of the NEC. Note that 310.15(B)(7)(c) applies to all feeders in dwellings. This means that if you have two subpanels, the ampacity of the conductors is not required to exceed the size of the service or feeder conductors calculated in 310.15(B)(7)(a) or (b). For example, if you have a 200-amp service fed by 4/0 AWG aluminum conductors and two 200-amp subpanels, the conductors to the subpanels will not be required to be larger than 4/0 AWG aluminum, unless there are temperature correction or adjustment factors that must be applied to the feeders. This is logical since there is no way the load on an individual subpanel feed can be greater than the load on the service conductors.

Using the new 310.15(B)(7)

Start by choosing the rating of the service disconnecting means or overcurrent protective device based on the load calculation for the service or feeder. The "rating” is the size of the service disconnecting means for the service or the overcurrent protective device for a feeder. The conductors are then required to have an ampacity of at least 83% of the service or feeder rating. If no other adjustments or corrections are required for the installation, then per Table 310.15(B)(16) we would size the conductors in the 75°C column. We are generally limited to 75°C by 110.14(C) since equipment terminations for 600-volt equipment is typically 75°C.

Let’s consider a 200-amp service rating: 200 amps multiplied by .83 results in a 166-amp conductor required for the service conductors. This would require a 2/0 copper or a 4/0 aluminum in the 75°C column per Table 310.15(B)(16). This is the same as the table was in the 2011 NEC.

What if a 200-amp feeder runs through an attic with a 125°F ambient temperature? The conductor in the attic is more than 10% of the length of the conductor, so we can’t use 310.15(A)(2) Exception. Table 310.15(B)(2)(a) requires a correction of 76%. Now we need a conductor that is 166 amps after a 76% correction is applied. Using a 90°C conductor, a 3/0 AWG copper conductor at 225 amps multiplied by .76 equals 171 amps, which meets the 83% and 166-amp conductor requirement.

If a 100-amp service is required — 100 multiplied by .83 equals 83 amperes. Therefore, the conductor required by Table 310.15(B)(16) in the 75°C column would be a 4 AWG copper conductor at 85 amperes or a 2 AWG aluminum at 90 amperes; either satisfies the 83-ampere conductor requirement. This is the same sizing that was allowed in the 2011 NEC.

Now let’s look at a feeder with four 100-amp SER cables that are bundled or touching (not maintaining spacing for longer than 24 inches). Each feeder feeds individual dwellings in a multifamily. What size conductors are required?

The rating is 100 multiplied by .83 equaling an 83-amp conductor. A 4 AWG copper or 2 AWG aluminum from 310.15(B)(16) in the 75°C column would have worked, except that there are 8 current-carrying conductors bundled. Section 310.15(B)(3)(a) requires a 70% correction. Now we need a conductor that is 83 amperes after having a 70% correction. Using a 90°C conductor allows us to start our calculation in the 90°C column. A copper 2 AWG conductor in the 90°C column is 130 amperes, which when multiplied by .70 equals 91amperes, which satisfies the 83-ampere conductor required.

What if our feeder is SE cable running through insulation? Section 338.10(B)(4) allows us to start our calculation using the rating of the conductor to do any correction or adjustments; however, the final ampacity cannot exceed the values in the 60°C column. Now we have to pick a conductor that has at least 83 amperes in the 60°C column. A 3 AWG copper or 1 AWG aluminum conductor having 85 amperes in the 60°C column would satisfy the 83-ampere requirement for a 100-ampere feeder that runs through insulation (for more than 10 feet or 10% of the length of the run, whichever is less).

The bottom line is that the old table at 310.15(B)(7) will still work, unless the installation requires that temperature correction or adjustment factors be applied. With the new language, we use 83% of the service or feeder rating for sizing the conductors, after all code requirements are applied.

John Stacey
IAEI Representative, CMP-6

Tags:  Focus on the Code  May-June 2013 

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Would addition of the control circuit conductors in one conduit of this power circuit run in parallel be a violation of having the same number of conductors and the same electrical characteristics

Posted By Jeff Sargent, Wednesday, February 13, 2013

Question

A parallel conductor branch circuit is run from a switchboard to a 3-phase rooftop air-conditioning unit using two metric designator 63 (2½ in. trade size) conduits with four 4/0 AWG copper conductors (3-phase, 1 EGC) in each conduit. One of the conduits also contains six 10 AWG Class 1, 120-volt control circuit conductors. Would the addition of the control circuit conductors in one conduit of this power circuit run in parallel be a violation of having the same number of conductors and the same electrical characteristics in each conduit? DB

Answer

The objective of 300.10(H) is to evenly divide the current across the conductors arranged in parallel. The requirements of 300.10(H) covering the conductors and the cable assemblies or raceways containing the parallel conductors have been developed based on the objective to evenly distribute the current through having parallel paths that have essentially the same impedance or in the case of dc circuits, resistance.

The provision of 310.10(H)(3) specifies that a raceway is to have the same number of conductors and the same electrical characteristics. The provision for the same number of conductors was developed based on a revision in the 2005 NEC submitted by a member of CMP-6 indicating that he had observed an installation of parallel conductors where multiple sets of the paralleled conductors had been installed in one raceway, while a single set had been installed in another raceway. The intent of the provision on the same number of conductors was based on having the same number of conductors in parallel in each raceway or cable.

The provision for raceways or cables to have the same electrical characteristics would be the primary consideration as to whether the control conductors in one of the parallel raceways results in a noncompliant installation. The same case could be made for branch-circuit conductors for a service receptacle or lighting outlet being run in the raceway with one of the parallel sets. Does installing these conductors in the raceway with one of the parallel sets now create different electrical characteristics and this becomes a physics exercise based on the thermal impact of the additional conductors? Can the AHJ turn this down simply because of the presence of the control conductors? I think so, because without calculation the AHJ now no longer knows whether the raceways have as close as possible to the same electrical characteristics. With that being said, the AHJ could turn to the provision in Section 725.51(B) that covers when it is necessary to apply ampacity adjustment (derating) factors to Class 1 circuit conductors that are installed in the same raceway with power conductors. Ampacity adjustment is required where the Class 1 circuits carry continuous current in excess of 10% of the control conductor ampacity and where the total number of power conductors and control circuit conductors exceeds three. Ampacity adjustment is not required where the continuous current does not exceed 10% of the control circuit conductor ampacity.


Jeff Sargent
NFPA Regional Electrical Code Specialist

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Tags:  Focus on the Code  March-April 2013 

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Dry-Type Transformer, Grounding & Bonding Terminations

Posted By Keith Lofland, Wednesday, February 13, 2013

Question

Grounding and bonding termination points in dry-type transformers are seemingly an issue in that the NEC apparently is silent on where in a dry-type transformer grounding and bonding conductors should be landed (terminated). In addition, many times installers utilize poorly chosen termination means such as installing a lug over a vented portion of the bottom of the transformer. Are there such termination requirements in the NEC and if so, where are they located? PC

Answer

Up to this point in the NEC language, I would agree with your assessment that the NEC might be silent on this issue other than perhaps 110.3(B) and the transformer manufacturer’s specifications. However, a proposal has been accepted by CMP-9 for the 2014 NEC to address grounding and bonding connections in transformer enclosures (see ROP Proposal 9-144). This new proposed provision located at 450.10(A), incorporates specific requirements for installing an equipment grounding terminal bar in transformer enclosures in accordance with 250.12 (Clean Surfaces). Section 250.12 requires nonconductive coatings (such as paint, lacquer, and enamel) on equipment to be grounded to be removed from contact surfaces to ensure good electrical continuity. Under this proposed requirement, this terminal bar would be prohibited from installation on or over any vented portion of the transformer enclosure. This type of termination utilizing the venting openings results in a less than effective grounding and bonding connection. These venting openings have not been evaluated as grounding and bonding connections and should not be depended upon to serve as an effective ground-fault current-fault return path.

An exception to this rule has also been proposed to address transformers with pigtail leads used as the connection means incorporating any of the methods at 250.8 (Connection of Grounding and Bonding Equipment) in lieu of an equipment grounding terminal bar.

Keith Lofland – CMP-9
IAEI Director of Education

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Tags:  Focus on the Code  March-April 2013 

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Is it code-compliant to install Type NM cable exposed in an attached residential garage? How about a detached garage?

Posted By Charles Palmieri, Saturday, September 01, 2012
Updated: Monday, February 04, 2013

Question

Is it code-compliant to install Type NM cable exposed in an attached residential garage? How about a detached garage? What about a detached residential building such as a storage shed? BG

Answer

Thank you for the inquiry. For clarity, I will frame my response. First, I will substitute the term residential with the term dwelling which is defined in NEC Article 100. Second, I will consider the attached garages or detached garages and storage sheds to be directly associated with one- and two-family dwellings. Third, all structures considered will be of Types III, IV, and V construction. For this discussion, I will focus my response to the language of the 2011 National Electrical Code and before I begin, I will state my understanding of your question. You wish to know if nonmetallic-sheathed cable is permitted to be installed as an exposed wiring method in an attached or detached garage or in a detached building such as storage shed. Whenever there is a need to determine the permitted uses of any wiring method, I begin by reviewing the XXX.10 Uses Permitted section for that specific wiring method. I will start by reviewing 334.10 which generally states that nonmetallic-sheathed cable is permitted to be used in accordance with its following five (5) listed items. For this discussion we will only consider the language in list items (1) and (3).

The language of 334.10(1) permits the use of nonmetallic-sheathed cable in one- and two-family dwellings including their attached or detached garages and their storage buildings. This section was revised for the 2011 edition of the NEC by inserting the words "and their attached or detached garages, and their storage buildings” after the word "dwellings.” The new language was added to make it clear that the use of nonmetallic-sheathed cable as an exposed wiring method in one- and two-family dwellings, including their attached and detached garages and storage sheds, is permitted. To further support this conclusion, I look at the previous editions’ language in 334.10(1) which stated that nonmetallic-sheathed cable was permitted in one- and two-family dwellings. This language did not prohibit exposed cable installations in a dwelling or its attached garages, but it was silent in regard to installations in detached garages or other detached structures associated with a dwelling.

Under previous editions of the Code, installations in detached structures associated with dwellings were guided by the language of 334.10(3). That section addresses installations of nonmetallic-sheathed cable in other structures which are not dwellings and the language gives us two basic requirements. (1) It restricts the use of the cable to those structures that conform to Types III, IV, and V construction and (2) it requires that the cable be concealed within walls, floors, and ceilings that provide a thermal barrier of material that has at least a 15-minute finish rating.

Keeping all this in mind and upon review of sections of 334.10(3) and the revised language of 334.10(1), it is clear that nonmetallic-sheathed cable is permitted to be installed exposed in one- and two-family dwellings, their attached and detached garages, and their storage buildings. It is additionally important to note that regardless of the building’s condition of occupancy where the cable is installed exposed, it must comply with the provisions of 334.15; and if it is determined that the installation is subject to physical damage, then guarding in accordance with 334.15(B) must be considered.

Additional sections of the Code relevant to the installation and routing of the cable will provide guidance for a compliant installation (see 300.4, for example). It is also helpful to note that structures are grouped into five general types. These types are summarized in the Informative Annex E titled, "Types of Construction,” which may be found on page 814 of the 2011 NEC (soft cover). I hope this information is helpful.

Charles Palmieri
IAEI Principal Member, CMP-7

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Tags:  Focus on the Code  September-October 2012 

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We have some radio equipment that uses a screw-type fastener to bond or attach the grounding conductor to the antenna assembly. Can this screw be any ordinary screw, or does it need to be a “listed” s

Posted By Tom Moore, Saturday, September 01, 2012
Updated: Monday, February 04, 2013

Question

We have some radio equipment that uses a screw-type fastener to bond or attach the grounding conductor to the antenna assembly. Can this screw be any ordinary screw, or does it need to be a "listed” screw meeting the requirements of 250.70 or, perhaps, 250.8? Does the screw need to be "green” in finish? Do the grounding and bonding rules in Article 250 apply to radio and television equipment? Or is Article 810 the only applicable rules that would apply? DB

Answer

Thank you for your correspondence. The question presented is frequently discussed by many with diverse results. Radio equipment as referenced in the question falls under the scope of Article 810 of the NEC.

We first need to point out that the term grounding conductor as referenced in the question and used in previous editions of the NEC has been revised to three more appropriate terms: grounding electrode conductor, bonding jumper, or bonding conductor. CMP-16 accepted these revisions throughout Article 770 and all Chapter 8 articles to provide consistency and correlation with defined grounding and bonding terms in Article 100, and to avoid the use of an undefined term in the communications articles.

Let’s begin with the first part of your question. Section 250.70 does apply for the connection to grounding electrodes as referenced in 810.21(K). If I understand the question correctly, we are referring to the grounding electrode conductor or bonding conductor termination to the equipment. Section 810.21 is silent as to the requirements for connection of the grounding electrode or bonding conductor to the equipment; therefore, the listing requirements of the radio equipment need to be followed.

As for the screw terminal, Chapter 8 has no requirements that would require the screw to be identified by a green color.

In the third part of the question dealing with the application of grounding and bonding rules of Article 250, we need to review the code arrangement in 90.3. The second paragraph of 90.3 points out that Chapter 8 is basically a stand-alone chapter, and that Chapters 1 through 7 only apply where specifically referenced in Chapter 8. One example is the reference to 250.70 in 800.21(K) and discussed above.

Tom Moore
IAEI Representative, Chairman-CMP-16

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Tags:  Focus on the Code  September-October 2012 

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Are there any other such receptacle replacement requirements?

Posted By Keith Lofland, Tuesday, May 01, 2012
Updated: Monday, February 04, 2013

Question

I know the Code requires GFCI protection for replacement receptacles in existing dwellings where receptacles are replaced in areas that would require GFCI protection under today’s Code. Are there any other such replacement requirements for other things such as AFCI protection elsewhere in the Code? DP

Answer

The GFCI requirement for replacement receptacles is located at 406.4(D)(3) in the 2011 NEC. An example of this would be at a non-GFCI protected kitchen countertop receptacle or a bathroom receptacle being replaced. New for the 2011 NEC are replacement receptacle outlets requirements for such things as AFCI protection, tamper-resistant receptacles and weather-resistant receptacles. Section 406.4(D)(4) requires AFCI protection for replacement receptacle outlets supplied by branch circuits that require AFCI protection elsewhere in the Code. The language in this new AFCI requirement will allow AFCI protection to be provided to the replacement receptacle by either an AFCI circuit breaker or by an outlet branch-circuit type AFCI device located at the replaced outlet or upstream on the supplying branch circuit. Both the receptacle and circuit-breaker type AFCI will provide protection for all receptacles and other outlets that are downstream on the branch circuit. It should be noted that this new receptacle replacement AFCI requirement for the 2011 NEC has a future effective date of January 1, 2014 for enforcement of this new requirement.

Section 406.4(D)(5) now requires listed tamper-resistant receptacles to be provided where replacement receptacles are installed at receptacle outlets that are now required to be tamper-resistant receptacles under today’s Code requirements. An example of this would be replacing existing receptacle outlets in the den or bedroom of an older existing dwelling unit as 406.12 requires tamper-resistant receptacles in all areas specified in 210.52. Section 406.4(D)(6) now requires weather-resistant receptacles to be provided where replacement receptacles are installed at receptacle outlets that are now required to be weather-resistant receptacles under today’s Code requirements. A good example of this would be replacing existing receptacle outlets in a damp or wet location such as an outdoor receptacle outlet at a dwelling unit or a commercial building as 406.9(A) and (B) requires listed weather-resistant receptacles at receptacles located in damp and wet locations.

— Keith Lofland, IAEI Director of Education

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Tags:  Focus on the Code  May-June 2012 

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Do washing machines require GFCI protection?

Posted By Mark Hilbert, Tuesday, May 01, 2012
Updated: Monday, February 04, 2013

Question

An inspector told me the other day that a washing machine in a dwelling unit required GFCI protection. I’ve looked and I can’t find that requirement in the 2011 NEC. Can you help me with this requirement? TA

Answer

Thank you for your correspondence. There is no specific requirement in the NEC for the washing machine itself to have GFCI protection. Section 210.52(F) requires a receptacle outlet to be installed for the laundry area and it must be supplied by a 20-ampere branch circuit in accordance with 210.11(C)(2). However, depending on the location of the receptacle outlet itself, GFCI protection may be required. For example, if the laundry area receptacle outlet (20-ampere, 125-volt) is located in a bathroom or an unfinished basement of a dwelling unit, GFCI protection would be required for the receptacle outlet in accordance with 210.8(A)(1) or (A)(5) respectively. Additionally, if the washing machine is located in a laundry room or utility room that included a sink, the laundry area receptacle outlet would have to be provided with GFCI protection if it is located within 1.8 m (6 ft) of the edge of the sink in accordance with 210.8(A)(7). The location of the washing machine and of the corresponding laundry area receptacle outlet is the determining factor as to the requirement for GFCI protection.

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Tags:  Focus on the Code  May-June 2012 

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Bonding Copper Piping for a Hydromassage Tub

Posted By Keith Lofland, Thursday, March 01, 2012
Updated: Monday, February 04, 2013

Question

A minimum 8 AWG copper bonding conductor is utilized to bond the hot and cold copper water piping rising from the ground to serve a hydromassage bathtub along with other metal components installed under the hydromassage bathtub. Why does the Code require installers to run a bonding conductor to the location of a double insulated circulating pump motor when this bond wire is not required to be connected to anything?

Answer

All metal piping associated with a hydromassage bathtub and all grounded metal parts in contact with the circulating water is required be bonded together using an 8 AWG solid copper bonding jumper. This bonding jumper is required to be connected to the terminal on the hydromassage bathtub circulating pump motor. Furthermore, this bonding jumper should not be connected to a double insulated circulating pump motor (680.74). A change was implemented in the 2011 NEC at 680.74 to require an 8 AWG or larger solid copper bonding jumper long enough to terminate on a replacement non-double insulated pump motor. This bonding jumper is to terminate to the equipment grounding conductor of the branch circuit of the motor when a double insulated circulating pump motor is used. This added language here at 680.74 is similar to the wording found at 680.26(B)(6)(a) for a double insulated circulating pump motor and possible replacement at a permanently installed swimming pool. This bonding jumper for a double insulated circulating pump motor is required to be in place in the event that the double insulated motor is replaced at a future date with a non-double insulated motor, which would require the bonding jumper for bonding to associated metal components. Inspectors and installers alike will have to decide what to do with the other end of this 8 AWG or larger solid copper bonding jumper if a double insulated circulating pump motor is employed and no metal piping and no grounded metal parts are present.

— Keith Lofland, IAEI Director of Education

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Tags:  Focus on the Code  March-April 2012 

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