FOR ALL STAKEHOLDERS TO HAVE A SUCCESSFUL PROJECT

Transcription

1 Our Goal is FOR ALL STAKEHOLDERS TO HAVE A SUCCESSFUL PROJECT with us and that together we keep people and structures safe and buildings economically viable to serve the needs of our community. We strive for: May 11th, 2016 EXCELLENT CUSTOMER SERVICE! and QUALITY INSPECTIONS! OUR NEXT MEETING IS JUNE 8th I. Customer Service Reminder, Mr. Rains

2 II. Consistency Questions 1)I have a neighborhood that Duke will not relocate lateral to the other side of the lot, assuming they no longer want to pay them to, where the garage is. EC has started running SER through the house from a main on one side to the panel in the garage. It is a main power feeder per (B)(7). This being said I was recently told by another inspector that they did not have to apply (B)(4) where in thermal insulation. I had been having another EC in another neighborhood derating the SER to 60 because 10' or 10% of it was in the insulation. Does this not apply to main power feeders? If so, why not? RAINS (B)(4) refers us to Part II of 334, excluding Then it further instructs us that in thermal insulation the ampacity shall be in accordance with the 60-degree C rating.

3 310.15(B)(7) of the NCEC allows a diversity demand for the feeder carrying the total load of the dwelling unit to use the table reducing the allowable conductor size by load diversity, not adjusting for thermal calculation. 2) When is it required to fill the nipple on a back to back service in a single family dwelling? HARTMAN Per of the code they should be sealed to prevent condensation issues due to thermal transfer. 3) Are liquidtight connectors that are approved for wet locations OK for direct burial? DELLINGER We would need to see the listing information from the manufacturer and UL. Generally, no per UL.

4 4)I have a service trough with meters and mains below. I added a meter and a main like all the existing equipment. The inspector turned me down and said I would have to change the service so that ALL mains were contiguous (even the existing mains)! Is this correct? SIMPSON We did have an interpretation that led us to that but as of 3/29/16 it s not. Per Mr. Starling at NCDOI: I lean towards the idea that grouping of disconnects is uniquely dependent of the structure it serves. The service disconnects for the structure should be arranged in a manner that allows someone to disconnect all the power from a building in one general location. I would agree that there should be no reason that other building components or systems should infringe on that area where the disconnects are located. Section (E)(2) helps the inspectors keep this area free from other equipment that do not belong in that special zone. However, meters, conduit, and other necessary electrical equipment should not necessarily be prohibited to be installed where they come between the handles of the disconnect.

5 5)I ran liquid tight flexible metallic conduit to join two sections of PVC raceway for service conductors to a building. I was turned down because there is no way to bond the flex. Does exception not apply? It seems like the intent is the same. KING NO, it only applies to a metal elbow. 6)What size breaker can I use to protect 12, fourteen gauge wires, ran in a conduit to feed 15A general use receptacles? WEST (B) (1) would prohibit this. You could divide the conductors in to multiple conduits to avoid this issue. 7)When performing Plan Review and Inspections on multi-occupancy dwellings, what is the responsibility of the reviewer concerning the individual units, and what is the responsibility of the inspector by CE policy. KALE

6 The review team is to only review to the unit panel as the rest takes too much time and is very subject to field change. We look at the units as individual residences that require no review. The inspector will cover all system elements for code compliance. 8)Is there any guidelines as to the location of a utility tap box used in conjunction with a utility transformer? BARNES The specs and location of the tap box would need to be identified for us to know if building/electrical protection is needed. 9)How do we resolve the conflict between CE Policy and Duke Energy s Policy on transformer location and clearances? RAINS We will require what is needed to protect the building. Duke Energy seems to be interested in other criteria. Their construction services book advises their customers to check with the local AHJ. The criteria we agreed to is still on our website.

7 10)When an elevator is required for a 5 story building to be used as a means of egress, how do we know in the plan review stage whether it requires Emergency Power (NEC 700) or Standby Power (NEC 701). What system is required is specified by the NCBC. If the electrical examiner is unsure of the appropriate call, I would suggest that the building examiner provide that information to the electrical examiner by . If there appears to be a conflict, then the Building CA could decide the issue. HARTMAN 11)When the water line is part of the GEC system, does the water line need to be connected at the street? If so, is this a CE SOP or is this per CMUD? DELLINGER NEC (A)(1) states we can use a metal underground water pipe for the grounding electrode. If it has no water in it is it a water pipe? It has long been Meck. County CE s interpretation that it has to be complete

8 to qualify. We have had two incidents of personnel injury when power was connected without the water system being complete. 12) I have 2 buildings located 10 feet apart, on the same property and same owner. Building A has the service and building B has a subpanel fed from building A. Can I install 2 ground rods between them and use them as the made electrodes for both? SIMPSON Per NEC the grounding electrode(s) shall be installed. This indicates that no duplicate use is allowed as posed in the question. 13) Does the low voltage data and voice cables installed underground in conduit have to be listed for a wet location? KING Cables generally have to be used in accordance with their listing (B) and GS 66. Underground conduits are wet location and the cables would need to be rated for wet locations. See communication circuits

9 which disagrees with GS. We don t see how either way will make a safety impact. 14) Can I install a NEMA 1 panel in a damp location (under a shelter outside)? WEST Well yes you can but the inspector will need to turn it down. NEMA I is for indoor locations and offers no protection from water penetration. If the location of the panel is well within the structure so as to avoid direct rain and dripping a NEMA 2 might could be used if inspector judged ok and the location as indoors. Generally, a NEMA 3 would be needed. 15)In the service panel, do I have to land my EGC 's directly on the neutral bar? KALE

10 In general terms no. There is no potential difference in the bars of grounded conductors and equipment grounding conductors at service if they are bonded together. Be sure to follow manufacturer s installations instructions. If not bonded and the can is the only common point, then EGCs are all that can land on the EGC bar. 16)We need to replace a 75 kva 480/208 transformer in our facility, do we need to have this replacement permitted? BARNES Yes. No exception is allotted for permitting this work in of the NC Admin. Code or NCGS. 17)Can a 50-amp receptacle be fed by a 30-amp circuit breaker? No (B)(1) and (B)(3) prohibits this. RAINS

11 18) Is there a limit on how many NM cables I can pull through a drilled hole in a wooden stud? HARTMAN No limit is prescribed by code. The key is what will fit without damaging the cable. Be aware of derating requirements as well. 19) Can EMT be installed under or in a slab? DELLINGER Yes. See Corrosion protection needs to be considered. Fittings need to be listed for the purpose. 20) We have some pre-wired office furniture that came with isolated ground receptacles. We did not provide an isolated ground with the branch circuit. Can we tie both of the grounds to our branch circuit ground? And do we have to change the isolated receptacles to nonisolated grounded receptacle? SIMPSON

12 The provision for isolated grounding is just that. You can t make a hybrid system out of it. You must either choose to follow the required grounding system as normal or choose the isolated system. 21)In the meter can shown in the picture below. I landed my GEC on the lug and the inspector turned me down. Was he correct? I do this all the time. KING

13 It appears the can is being used to connect the GEC to the grounded conductor. That is not allowed per NEC If it is a supplemental GEC it is allowed as shown.

14 22)We added some lighting in an existing open office area, all of our mc cable and lights were supported and secured per the NEC, the inspector turned my job down citing that existing defects were my responsibility because we added wiring. He said if you alter the ceiling its yours even though the defects had nothing to do with our scope of work. Is he correct? WEST If the contractor s scope of work meets the code, then an RQ needs to be created and the owner advised to get violations corrected. If an existing circuit or feeder is used it must be in compliance as well. 23)We changed out the 2x4 lay ins at an old office building, all we did was disconnect and reconnect wires which were Romex. All Romex was supported properly. Are we required to replace Romex with MC? NO! Like for like replacement is allowed if it met the code at the time. If other, then replacement to code occurs. KALE

15 24)I was turned down for disposal not being installed with a receptacle outlet installed under sink. We have been allowed in the past to leave a cord and plug connected disposal out, as long as we provide outlet. Has the policy changed? BARNES Our policy (6.2) for several years states the disposal must be set for final. 25)I installed an outlet with a metal box in a media panel, the metal box is attached to the media panel by machine threaded screws and the metal box is properly bonded, so why would the inspector turn me down for not bonding the media panel? RAINS In this case the grounding is fine unless the manufacturer s instructions state differently.

16 26)In looking at Duke Energy s new Requirements for Electrical Service and Meter Installation for NC and SC, what are Plan Reviews obligations for documenting these changes on approved drawings? Specifically, in regards to fig. 47A and 47D. Fig.47A indicates the meters and disconnects be mounted over the service trough. Fig. 47D indicates meters and disconnects mount below service trough when a C/L fuse cabinet is mounted ahead of trough. Does plan review need this documented on single line diagram prior to approval since this is a utility provider requirement? HARTMAN We have no obligation to Duke s standards. 27) I have a project in plan review that is a 4 story private school with class rooms and administrative offices. The NEC has changed has added an exception to Lighting Loads for Specified Occupancies.

17 The following exception to NEC reads: Exception: Where the building is designed and constructed to comply with an energy code adopted by the local authority, the lighting load shall be permitted to be calculated at the values specified in the energy code where the following conditions are met: (1) A power monitoring system is installed that will provide continuous information regarding the total general lighting load of the building. (2) The power monitoring system will be set with alarm values to alert the building owner or manager if the lighting load exceeds the values set by the energy code. (3) The demand factors specified in are not applied

18 to the general lighting load. We use the 2012 NC Energy Conservation Code as our required energy code of the NCECC addresses the Building area method and the space-by-space method to be calculated at 0.89 va. per sq.ft. NEC requires 3 va. Per sq. ft. This is around 1/3 of the required load of NEC (A) Other than checking that are not applied, what requirement will be needed at plan review to ensure the designer has a code compliant design? (B) Will this have any impact for the field inspector for verification of the monitoring system and required alarms for this design? DELLINGER

19 The designer needs to provide the calculation used if the exception is used. The monitor and alarm system need to be shown as required also. 28) The new Duke Energy manual requires the minimum trough size 14 X 14. The 2014 NEC (A)(3) will be a problem for contactors. How is this now being handled in the field by inspectors? Will our field inspector s approach this differently with Duke s new trough size? The contractor will have the responsibility to meet code appropriate clearances and continue to bond all service equipment as required by code. SIMPSON 29) Can the light over the kitchen sink be on the same circuit as the disposal? KING

20 (A)(2) allows it if the disposal does not exceed 50% of the circuit. 30) Can a ground rod be installed in a building? WEST Code does not prohibit this. 31) Can MC cable be used in brick work? KALE See &.12. MC is not to be embedded in mortar except in dry locations. Stubbing thru an exterior wall is not an issue. Otherwise the cable needs to be rated for the environment. 32) Can the GEC be spliced in panels on ground bars? BARNES Yes, per (D)

21 33) Is a detached building disconnect means to be service rated? RAINS Maybe. See and ) When using metallic flex between a 480V to 120/208V transformer to a 120/208V panel, is it necessary to bond the flex with bond bushings or bonding locknuts? No. See NCEC and the following.

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27 Review of 2014 Residential Changes