Code Change of the Week

This is in the top ten Code changes for 2011.  I hear the stories about being ZAPPED off the neutral on a multi-wire branch circuit, being zapped is lucky!  It is the ones that have been electrocuted that were not so lucky to be just ZAPPED.  So after years of hearing these stories it has become a Code requirement.  This used to be a requirement when we had two circuit attached to one device such as a receptacle or equipment so in 240.15(B)(1) it permits the use of single pole breakers with identified handle ties to be used in lieu of a two pole or three pole breaker.

210.7  was formerly divided into two sections parts A and B.  Section 240.15(B)(1) also requires that when used, single pole circuit breakers with handle ties (identified) SHALL BE permitted to be used to protect a multi-wire branch circuit.  So one question that comes to mind can two Arc Fault breakers be used in this manner?  I have had some who said that the AHJ did not allow this practice because it was not listed!  Does this section give us some relief when using this practice.  A certain manufacturer has an informational manual that shows using two single pole Arc
Faults in this manner for a multi-wire branch circuit..  That paper can be found in one of my other weekly columns, on this web site.

When working in the field and you pull a common neutral for a couple (multiple) of branch circuits you have to be able to disconnect the circuits at that same time (simultaneous).  This would require a two pole or three pole circuit breaker to be able to accomplish this feat.  You may use identified handle ties on single pole circuit breaker to make this happen.  The intent of this section has been around for a long time, but in my daily inspections I still have to issue a correction notice for this practice.  I find it more often in housing and it is usually easier to find when the contractor runs a 3 wire branch circuit(black white and red wire).  Any time you run a 3 wire branch circuit in a residence it requires a common trip circuit breaker at the point at which the branch circuit originates, the panel. There are no exceptions! 

210.7 Multiple Branch Circuits. Where two or more branch circuits supply devices or equipment on the same yoke, a means to simultaneously disconnect the ungrounded conductors supplying those devices shall be provided at the point at which the branch circuits originate.

So as you can see I find it all the time, there are several circuits tied together in this manner in this one panel.  The ones with the wire through them may trip one circuit but it may not trip them all.  So when you wire residences remember that all multi-wire circuit need to be on a common trip breaker even Arc Faults.

Till next week be safe

Jake

This weeks Code change is based on load calculations from article 220.   220.43(B) requires that a load of 150 va be included for each 2’ of track lighting.  This can add up to be a substantial load when not necessarily needed.  There is an exception to this section that will allow us to include the loads for our calculation to be based on a device that can limit the current to the track.  This device has a current limiting feature that will as it states “limit the current” whether it is 10’ long or 100’ long section of track.

Click on the link or cut and paste it to see the brochure for a couple of manufacturers track limiters.  The ones that I have seen out in the field have been from 1 ampere thru 13 amperes.  So using these devices will help reduce the loads calculated for track lighting loads.  This may not seem like a major factor but if you are sizing the lighting load for a furniture store or an art gallery these limiters will help in calculating the service load.  Another type of limiter that I have seen is a panel that has these limiters built into to it using 1 to 13 amperes as circuit limits.

 http://www.cooperindustries.com/content/dam/public/lighting/resources/library/literature/Halo/CurrentLimiterBrochure.pdf

http://www.junolightinggroup.com/literature/Subpanel_Brochure.pdf

Till next week work safe be safe

Jake

In the 2011 NEC they changed the numbering to the Ampacity Table 310.16,  Also moved  is the ampacity correction factors to its own table.

In the 2011 NEC article 110.24 has a few changes that need to be be addressed.  Under 110.24(A) Field Marking, service equipment in other than a dwelling unit shall be field marked with the maximum available fault current.  This is something you will have to get with the utility or the engineer for the project to be able to calculate.  The field markings will have to be able to with stand the elements when a attached to a disconnect or panelboard out in the field.   Section 110.24(B) Modifications will make you as the installer responsible to attach newly calculated fault current information to the equipment based on modification made to the circuits.  All information provided will have to with stand the elements in which they are installed so a Sharpie or Magic Marker is not going to meet the requirements of this new change because they don’t last out in the weather.   Till next time work safe…

For the 2011 edition of the NEC on page 275 of the softbound Code book, they have added the requirement for field identification of all switchboards and panelboards, to indicate where the power to that equipment originates.  It will be easier to mark these panel and switch boards when they are installed.  Trying to find the source 5 or 10 years down the road has always been a time consuming project that only takes minutes when first installed.  A great addition to the code, will make life as an electrician easier in the future.  Till next time work safe and be safe.

Jake

The yellow highlighted material below is a new Code change for 2011.  GFCI protection has been expanded to cover other areas that have been shown to have problems.

Till next time work safe and be safe.

Jake

With the impending adoption of the 2011 NEC I will try to pick out a few changes that will affect the way we wire houses.  The first is minor change but it could have your job fail inspection.  210.52 (A)(4) again is a minor change but could end  you fail an inspection.

As you can see in the picture the outlet on the counter was used to cover the 2’ wall space next to the sliding door.  Under the 2011 NEC you will no longer be able to use the counter outlet to cover the wall space

With all the new electronic dimmers there seems to be a need for neutral conductors at switch locations.  This new code section in the 2011 NEC requires that if you cannot access a switch box after the installation then a neutral conductors is required to be installed in the box.  If you can access the box after the installation then the neutral will not be required until it is needed.

This is a 2011 code change and will not affect installation being done now but when it is adopted this will be something all the inspectors will be looking for.

Until next week

Be safe, always check to see if it is hot.

When sharing the Neutral of a multi-wire branch circuit, the circuit breaker has to be common trip.

Single phase, Three phase circuits now require a 2 pole or three pole circuit breaker.