REVIEW OF CODE BREAKFAST QUESTIONS Brought to you by fellow members who attended the Section Meeting

Do the requirements of (C) apply to underground communication wires and cables entering buildings?

2008 NEC – (C) does not exist 2008 NEC – (C) does not exist 2008 NEC 310.8(C) refers to Wet Locations 2008 NEC 310.8(C) refers to Wet Locations 2008 NEC does not state that the requirements of (C) do not apply 2008 NEC does not state that the requirements of (C) do not apply

Chapter 8 is a stand-alone chapter. It is reasonable to assume that nothing in Chapter 3 applies to these installations unless specifically referenced – See 90.3 Chapter 8 is a stand-alone chapter. It is reasonable to assume that nothing in Chapter 3 applies to these installations unless specifically referenced – See 90.3

2011 NEC does add the language that the requirements of (C) DO NOT apply 2011 NEC does add the language that the requirements of (C) DO NOT apply Why was this added? Why was this added?

Are ceiling insert fans, wall insert fans, and ceiling insert fan/light combinations, that are intended to be mounted over bathtubs, showers, or within the zone above a bathtub or shower area (as defined in (D)) required to be GFCI protected? Are ceiling insert fans, wall insert fans, and ceiling insert fan/light combinations, that are intended to be mounted over bathtubs, showers, or within the zone above a bathtub or shower area (as defined in (D)) required to be GFCI protected?

The zone described in (D) The zone described in (D) 3 feet horizontally 3 feet horizontally 8 feet vertically 8 feet vertically From the top of the bathtub rim or shower stall threshold From the top of the bathtub rim or shower stall threshold

Yes, GFCI protection is required as per the listing of the product Yes, GFCI protection is required as per the listing of the product UL White Book – Product Category GPWV UL White Book – Product Category GPWV Is usually printed in the instruction sheet Is usually printed in the instruction sheet

Is the Grounding Electrode Conductor (GEC) permitted to occupy the same raceway with branch circuit conductors?

Example – A run of 1” EMT leaves the panel with four 12 AWG branch circuit conductors and one 6 AWG bare GEC Example – A run of 1” EMT leaves the panel with four 12 AWG branch circuit conductors and one 6 AWG bare GEC At a junction box near the ground rod, the 6 AWG exits the raceway/box system and travels down the wall to the ground rod At a junction box near the ground rod, the 6 AWG exits the raceway/box system and travels down the wall to the ground rod

Can the conductor be in this raceway? Can the conductor be in this raceway? A – Yes! It is not prohibited A – Yes! It is not prohibited

What other rules must we follow? What other rules must we follow? Table 1 Chapter 9 – Conduit fill Table 1 Chapter 9 – Conduit fill (E) – Bonding of ferrous enclosures for GECs (E) – Bonding of ferrous enclosures for GECs

2011 NEC – 695.6(D) adds Electrical Metallic Tubing as a permitted wiring method from the Fire Pump Controller to the Pump Motor. Does the same apply to the control circuit wiring?

2011 NEC 2011 NEC NO! NO! (E) (E) A proposal is needed to correct this A proposal is needed to correct this

If an enclosure is rated Type 2 or 3R, may drainage openings be field installed, or must they be factory provided?

According to UL, either method is acceptable According to UL, either method is acceptable Many enclosures do come with knock-outs intended to be used as weep holes Many enclosures do come with knock-outs intended to be used as weep holes Others do not, but a hole can be drilled in the field to provide this feature Others do not, but a hole can be drilled in the field to provide this feature Always follow instructions Always follow instructions

Does the NEC permit using the same grounding electrode for two separate systems with two different voltage ratings, such as 120/240 and 480/277Y?

It is permitted It is permitted Actually, it is mandated Actually, it is mandated

Health Care Facility Question - In health care facilities is ground fault protection for operation of service and feeder disconnecting means required to be fully selective such that the feeder device but not the service device shall open on ground faults on the load side of the feeder device. Is a six cycle minimum separation between service and feeder ground fault tripping bands required?

First part – Yes, 2 levels of ground fault (service main and branch) are required in a health care facility. This requirement makes sure that the main does not open in the event of a ground fault downstream of a feeder device. This minimizes the disruption to critical circuits in a health care facility.

Second part – Maybe. The 2011 NEC was changed to recognize the fact that newer solid state tripping devices do not require the 6 cycle separation for coordination required by older analog devices. However, the manufacturer and the device trip curves still needs to be consulted in case the tolerances still require that separation for coordination. New solid state breaker on left. Old ground fault relay on right.

New device ground fault trip curve, narrow band, can be coordinated without 6 cycle separation. Old device ground fault trip curve, wide band, not as accurate, 6 cycle separation for coordination required

Will the Code permit Decepticons to alter their appearance during a...

Sorry, wrong Transformers… Sorry, wrong Transformers…

Will the Code permit the installation of the primary and secondary conductors of an indoor transformer in the same raceway? Will the Code permit the installation of the primary and secondary conductors of an indoor transformer in the same raceway?

If all conductors are operating at 600 volts or under….. If all conductors are operating at 600 volts or under….. Then yes, it is permitted Then yes, it is permitted 310.3(C)(1) – 2011 NEC 310.3(C)(1) – 2011 NEC

If any conductors are over 600 volts… If any conductors are over 600 volts… Then, no, it is not permitted Then, no, it is not permitted 310.3(C)(2) – 2011 NEC 310.3(C)(2) – 2011 NEC

Where the voltage between service conductors does not exceed 300 volts and the roof is guarded or isolated, may a reduction to 3 feet of clearance from the roof be permitted?

2008 NEC – No! 2008 NEC – No! No such exception exists No such exception exists

2011 NEC – Yes! 2011 NEC – Yes! The exception was added to this edition of the code The exception was added to this edition of the code A good idea? A good idea?

Does the same apply to Article 225 Outside Branch Circuits & Feeder installations?

2008 & 2011 NEC 2008 & 2011 NEC The language is in neither The language is in neither A proposal is needed to make the language in Article 225 uniform with Article 230 A proposal is needed to make the language in Article 225 uniform with Article 230

Where conductors of more than one PV system occupy the same junction box or raceway with removable covers, are AC and DC conductors of each system required to be grouped separately by wire ties or similar means? Where conductors of more than one PV system occupy the same junction box or raceway with removable covers, are AC and DC conductors of each system required to be grouped separately by wire ties or similar means?

2008 NEC – No such requirement exists 2008 NEC – No such requirement exists 2011 NEC – Yes – 690.4(B)(4) 2011 NEC – Yes – 690.4(B)(4) Grouped once and then every six feet Grouped once and then every six feet

Do the equipotential bonding requirements for perimeter surfaces in (B)(2) apply to a listed, self-contained spa or hot tub installed above a finished floor?

In the previous picture, it is clear that bonding would not help In the previous picture, it is clear that bonding would not help You can’t fix stupid… You can’t fix stupid…

A new Exception in relaxes the rules for equipotential bonding for INDOOR installations above a finished floor. A new Exception in relaxes the rules for equipotential bonding for INDOOR installations above a finished floor. The bonding requirements in (B)(2) DO NOT apply The bonding requirements in (B)(2) DO NOT apply

What do the letter codes that designate various insulation types mean? What exactly is THHN?

The letter “R” represents a 60° C temperature rating, such as RW The letter “R” represents a 60° C temperature rating, such as RW The letter “T” represents a thermoplastic insulation with a 60° C temperature rating, such as TW The letter “T” represents a thermoplastic insulation with a 60° C temperature rating, such as TW

The letter “W” represents an insulation suitable for wet locations, such as TW The letter “W” represents an insulation suitable for wet locations, such as TW The letter “N” represents a nylon outer jacket, such as THHN The letter “N” represents a nylon outer jacket, such as THHN

The letter “X” represents a conductor coated with a cross-linked polymer, such as XHHW The letter “X” represents a conductor coated with a cross-linked polymer, such as XHHW A “-2” designation at the end of the identifier string indicates that the conductor is suitable for use at 90º C in both wet and dry locations, such as THWN-2 A “-2” designation at the end of the identifier string indicates that the conductor is suitable for use at 90º C in both wet and dry locations, such as THWN-2

Each “H” adds 15º C to the temperature rating of a conductor Each “H” adds 15º C to the temperature rating of a conductor

Example THW Example THW T = thermoplastic 60º C T = thermoplastic 60º C H = add 15º C H = add 15º C W = wet locations W = wet locations THW = thermoplastic 75º C wire suitable for wet locations THW = thermoplastic 75º C wire suitable for wet locations

Example THHN Example THHN T = thermoplastic 60º C T = thermoplastic 60º C H = add 15º C x 2 = 30º C H = add 15º C x 2 = 30º C N = nylon outer jacket N = nylon outer jacket THHN = thermoplastic 90º C wire with a nylon outer jacket THHN = thermoplastic 90º C wire with a nylon outer jacket

Example THWN Example THWN T = thermoplastic 60º C T = thermoplastic 60º C H = add 15º C H = add 15º C W = wet locations W = wet locations N = nylon outer jacket N = nylon outer jacket THHN = thermoplastic 75º C wire with a nylon outer jacket suitable for wet locations THHN = thermoplastic 75º C wire with a nylon outer jacket suitable for wet locations

THWN-2 THWN-2 Thermoplastic 90º C with a nylon outer jacket suitable for use in wet locations Thermoplastic 90º C with a nylon outer jacket suitable for use in wet locations

Example XHHW Example XHHW X = cross-linked polymer 60º C X = cross-linked polymer 60º C H = add 15º C x 2 = + 30º C H = add 15º C x 2 = + 30º C W = wet locations (take away one H) W = wet locations (take away one H) XHHW = cross-linked polymer 90º C wire in dry locations and 75º C in wet locations XHHW = cross-linked polymer 90º C wire in dry locations and 75º C in wet locations XHHW-2 = 90º C rated in wet locations XHHW-2 = 90º C rated in wet locations