IAEI EASTERN SECTION REVIEW OF CODE BREAKFAST QUESTIONS Brought to you by fellow members who attended the Section Meeting
UNDERGROUND WIRING Do the requirements of 310.10(C) apply to underground communication wires and cables entering buildings?
UNDERGROUND WIRING • 2008 NEC – 310.10(C) does not exist • 2008 NEC 310.8(C) refers to Wet Locations • 2008 NEC 800.47 does not state that the requirements of 310.10(C) do not apply
UNDERGROUND WIRING • 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
UNDERGROUND WIRING • 2011 NEC 800.47 does add the language that the requirements of 310.10(C) DO NOT apply • Why was this added?
BATH FANS • 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 410.10(D)) required to be GFCI protected?
BATH FANS • The zone described in 410.10(D) • 3 feet horizontally • 8 feet vertically • From the top of the bathtub rim or shower stall threshold
BATH FANS • Yes, GFCI protection is required as per the listing of the product • UL White Book – Product Category GPWV • Is usually printed in the instruction sheet
GROUNDING ELECTRODE CONDUCTOR Is the Grounding Electrode Conductor (GEC) permitted to occupy the same raceway with branch circuit conductors?
GROUNDING ELECTRODE CONDUCTOR • 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
GROUNDING ELECTRODE CONDUCTOR • Can the conductor be in this raceway? • A – Yes! It is not prohibited
GROUNDING ELECTRODE CONDUCTOR • What other rules must we follow? • Table 1 Chapter 9 – Conduit fill • 250.64(E) – Bonding of ferrous enclosures for GECs
FIRE PUMPS 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?
FIRE PUMPS • 2011 NEC • NO! • 695.14(E) • A proposal is needed to correct this
ENCLOSURES If an enclosure is rated Type 2 or 3R, may drainage openings be field installed, or must they be factory provided?
ENCLOSURES • According to UL, either method is acceptable • 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 • Always follow instructions
GEC (again) 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?
GEC (again) • It is permitted • 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?
Answer - Article 517.17 (C) Selectivity • 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.
Answer - Article 517.17 (C) Selectivity • 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.
Answer - Article 517.17 (C) Selectivity 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
TRANSFORMERS Will the Code permit Decepticons to alter their appearance during a...
TRANSFORMERS • Sorry, wrong Transformers…
TRANSFORMERS • Will the Code permit the installation of the primary and secondary conductors of an indoor transformer in the same raceway?
TRANSFORMERS • If all conductors are operating at 600 volts or under….. • Then yes, it is permitted • 310.3(C)(1) – 2011 NEC
TRANSFORMERS • If any conductors are over 600 volts… • Then, no, it is not permitted • 310.3(C)(2) – 2011 NEC
SERVICES 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?
SERVICES • 2008 NEC – No! • No such exception exists
SERVICES • 2011 NEC – Yes! • The exception was added to this edition of the code • A good idea?
SERVICES Does the same apply to Article 225 Outside Branch Circuits & Feeder installations?
SERVICES • 2008 & 2011 NEC • The language is in neither • A proposal is needed to make the language in Article 225 uniform with Article 230
SPEAKING OF SOLAR • 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?
SOLAR PV • 2008 NEC – No such requirement exists • 2011 NEC – Yes – 690.4(B)(4) • Grouped once and then every six feet
Equipotential Bonding Do the equipotential bonding requirements for perimeter surfaces in 680.26(B)(2) apply to a listed, self-contained spa or hot tub installed above a finished floor?
Equipotential Bonding • In the previous picture, it is clear that bonding would not help • You can’t fix stupid…