Code Change of the Week

First of all for today I hope you all enjoyed the day off to celebrate the annual Labor Day holiday.  You all work so hard an a day off to celebrate that hard work is deserved.

Todays news letter has to do with Arc Flash reduction, which is a requirement of the Code to help reduce an arc flash incident if one was occur when someone was working on a live “Hot” piece of switch gear.  The methods described in the article would allow someone to work on a main switch or disconnect that is hot and set the breaker or by-pass switch to maintenance mode so that if an incident was to occur it would clear almost instantaneously reducing the incidents arc flash. Thereby giving the worker added protection from a possible disastrous arc flash incident. 

This section first introduced in 2011 has been updated in the 2014 giving us some additional ways to reduce the hazard for workers who are working within the Arc Flash Boundary as defined NFPA 70E.  Based on the 2014 guide lines for mitigating the hazards of working on energize switch gear, there are now several ways to limit the time a circuit breaker will  take to shut off reducing the arc flash incident. All of these methods will require you to research the methods to find the one that works for your installation. 

A few contractors have asked about ways to work around this code article, especially ones who are working on high end residential projects.  Homes with 1200 ampere services or larger.  One way would be to have multiple mains smaller than 1200 amperes or use fused disconnects for mains, both which are not covered by this article. 

When designing and building a service this large you would have to have an engineer involved because of Florida statute 471.003 h which only allows an electrical contractor to design and build a residential services up to 600 amperes at 240 volts, and commercial services up to 800 amperes at 240 volts.. So next time you encounter a large service (1200 amperes or larger) commercial or residential maybe you can suggest a couple of smaller mains rather than going with the larger one.   

See the Code section 240.87 below:

240.87 Arc Energy Reduction

Where the highest continuous current trip setting for which  the actual overcurrent device installed in a circuit breaker is rated or can be adjusted is 1200 A or higher, 240.87(A) and (B) shall apply.

(A) Documentation. Documentation shall be available to those authorized to design, install, operate, or inspect the installation as to the location of the circuit breaker(s).
(B) Method to Reduce Clearing Time. One of the following or approved equivalent means shall be provided:

(1) Zone-selective interlocking

(2) Differential relaying

(3) Energy-reducing maintenance switching with local status indicator

(4) Energy-reducing active arc flash mitigation system

(5) An approved equivalent means

All of the ways to minimize an arc flash incident will have to be done under engineering supervision in order to meet one of the five methods required in the above Code section.

Till next time be safe work safe.

Jake

Out in the field we do it all the time, we back feed a transformer with 208v and boost it up to 480v to feed a piece of equipment, or to use it to help with voltage drop in a long run, but now the Code has made it a requirement to be done in accordance with the manufacturer’s instructions.  Not all transformers have these instructions.

Have a question you like answered, email me at jleccemail@hotmail.com

Till next time be safe work safe

Jake

This is a new requirement in the 2014 Code that has already been amended in the 2017 Code.  In the 2014 it requires a 15 or 20 ampere receptacle

to be installed within 50’ of the service area.  Then in the 2017 Code they amended it so that a receptacle will not be required if the voltage of the service

is above 120 volts to ground for services in and around Electrically driven or controlled irrigation machines or near natural or artificial bodies of water in

articles 675 and 682 .

2017 NEC 210.64 Exception No. 2: Where the service voltage is greater than 120 volts to ground, a receptacle outlet shall not be required for

services dedicated to equipment covered in Articles 675 and 682.

So in the picture below you would have to add a transformer and panel to feed a 120 volt GFCI protected receptacle unless it is a service for equipment

covered in articles 675, and 682..

Till next time work safe be safe……

Jake

This weeks comments comes from a recent inspection where the inspector asked the contractor to show a listing for the fixture that he was using next to a pool, that would meet the requirements of this new Code Section 680.22(B)(6). His request was to show that the two (2) wire fixture did not need grounding.  The fixture was listed as a low voltage luminaire but did not specifically show that it did not need grounding.  The fixture had only two wires and nothing in the manufacturers instructions show grounding the fixture. I asked the contractor if the inspector checked out the type of transformer he used and he said he did not.

The second part of this new section was the use of a transformer that met the requirements of section 680.23(A)(3) which means it is list for use as a pool or spa as a power supply to a fixture. (isolated winding type with an ungrounded secondary that has a grounded metal barrier between primary and secondary or an approved system of double insulation between the primary and secondary windings)  The transformer would also have to have specific low voltage contact limits as laid out in 680.2 definitions. (15 volts (RMS) for sinusoidal ac, 21.2 volts peak for nonsinusoidal ac, 30 volts for continuous dc, and 12.4 volts peak for dc that is interrupted at a rate of 10 to 200 Hz.)

This is a new change which allows us to install Low Voltage lighting right next to a pool, the fixture not being grounded is a requirement of this section but only one of three requirements of this new section, so you have to pay attention to the total section when installing lights next to a pool or spa.  Make sure that you are complying with all the requirements of this section.

Click on the picture below to see the whole slide

Till next time be safe and work safe.

Jake

Got a question?  Send it in, I will try and get you an answer.

In the 2014 Code we are being asked to identify or group each neutral with each circuit it serves when there are more than one neutral in a conduit , enclosure, box or switchboard.  This is already being enforced in some municipalities based on the safety factor.  As most of you know disconnecting the wrong neutral can lead to burnt out appliances and even fires.  So this is going to be a major change that is going into effect in January.  In some of the installations that I have seen they identified the neutral by numbering them according to the circuit they served. 

If you have multiple circuit in a conduit you will need to identify or group the neutral with the phase conductors it serves.  This is going to take time to do and will also hold up your job if not done properly.

If you can only see a portion of the picture just click on it

Till next time be safe work safe, and Happy Thanksgiving from us to you.

Darlene and Jake

New for 2014 Energy Management Systems, deals with these types of systems.

We probably should have had this in the Code along time ago, but better late than never.

Our first Continuing Education Classes for 2018 cycle will be held at Peninsular on December 5 and 6 from 6pm to 9pm.

You can check out the classes at our Web site.    www.electricalcodeconnection.com

Till next time be safe work safe

Jake

   This weeks 2014 Code change comes from section 200.4(B) which deals with neutrals grouped in panelboards or enclosures.  Then identifying them so that you don’t mistakenly disconnect the wrong one and send an over or under voltage  to a piece of equipment and possibly burn it up.  This section requires us to identify the neutral conductor for each circuit or circuits it serves.  This is for single circuit or multi-wire circuit. 

   Over the years I have seen electricians working on circuits only to disconnect the neutral to move it around to make room for another neutral conductor, only to disconnect it while the circuit it serves was still energized.  This resulted in a burnt out refrigerator or computer that was on a multi-wire circuit.

   I have seen a few good ways to ID the neutrals by either numbering them with the corresponding circuit number(s) on each neutral or grouping them with a piece of the sheath from NM cable marked with the circuit ID. 

   There are a couple of Exceptions where you can tell which neutral goes with a particular circuit of a cable or conduit installation, or when there just isn’t room to mark the wire in an existing installation where the conductors are pulled through a box or enclosure without splices.

Till next time work safe be safe and keep an eye on your helper.

Jake

This question has come up several times in the last couple of weeks. How close can I put my low voltage lights near a pool?

Section 680.22,B6 allows us to install LV fixtures closer than 5’ but they have to meet 680.23, A 2  for the type of transformer that is allowed to feed the fixtures.

680.22 B(6) Low-Voltage Luminaires. Listed low-voltage luminaires not requiring grounding, not exceeding the low-voltage contact limit, and supplied by listed transformers or  power supplies that comply with 680.23(A)(2) shall be permitted to be located less than 1.5 m (5 ft.) from the inside walls of the pool.

(2) Transformers and Power Supplies. Transformers and power supplies used for the supply of underwater luminaires, together with the transformer or power supply enclosure, shall be listed for swimming pool and spa use. The transformer or power supply shall incorporate either a transformer of the isolated winding type, with an ungrounded secondary that has a grounded metal barrier between the primary and secondary windings, or one that incorporates an approved system of double insulation between the primary and secondary windings.

Till next time

Be safe, work safe

Jake

A new annex has been added to the 2914 NEC Annex J which give us some guidance when dealing with ADA requirements.

You will no longer have to hunt for the ADA requirements for electrical installations, it will be in our Code book.

Till next time be safe work safe

Jake

Section 220.12 the Lighting load for listed occupancies has a new exception.  It allows us to use the lighting

demands from the energy code as long as they meet the requirements of the exception.

Till next time be safe work safe

Jake