Wall space for Outlets 210.52(A)(2)(1) Residential receptacles

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This section is often mis-understood when making the measurement or just understanding the requirements of the section to meet the requirements for outlet spacing in a residential home. I hear people says walls 1’ (12’”) or more need outlets, but that is for countertops in kitchen and similar work surfaces covered in section 210.52(C)(1).  In the picture below we have several French doors separated by wall space less than 2’ in width.  This section does not require us to install outlets in these wall areas.  As stated in the section walls less 2’ (24”) or more need to have receptacle outlets installed.  If the space is less than 24” then outlets need not be installed.

210.52(A)(2)(1) Wall Space.

As used in this section, a wall space shall include the following:

(1)  Any space 600 mm (2 ft) or more in width (including space measured around corners) and unbroken along the floor line by doorways and similar openings, fireplaces, and fixed cabinets that do not have countertops or similar work surfaces

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Till next time be safe work safe.

Jake

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HOW TO SIZE A RESIDENTIAL SERVICE PER SECTION 310.15(B)(7), USING THE 83% RULE

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Screenshot 2023-02-19 121040

Sizing of Service and/or Feeder Conductors for a dwelling unit PER SECTION 310.15(B)(7) see Example D7 in ANNEX D in the back of the Code book.

Service conductors and feeders for certain dwellings are permitted to be sized in accordance with 310.15(B)(7).

If a 200-ampere service is required, to select the service conductor size is as follows:

200 amperes (the size of required main) × 0.83 = 166 amperes per 310.15(B)(7).  (THIS IS THE 83% RULE)

If no other adjustments or corrections are required for the installation, then, in accordance with Table 310.15(B)(16), a 2/0 AWG Cu which is good for 175 amperes or a 4/0 AWG Al  which is good for 180 amperes will meet this rating at 75°C (167°F).

The following is the section from the 2017 Code book.

310.15(B)(7) Single-Phase Dwelling Services and Feeders.

For one-family dwellings and the individual dwelling units of two-family and multifamily dwellings, service and feeder conductors supplied by a single-phase, 120/240-volt system shall be permitted to be sized in accordance with 310.15(B)(7)(1) through (4).

As you can see this section it is for “one and two family dwellings, and multifamily dwellings”that use 120/240 voltages for services and/or feeders. In this section a reduced neutral is allowed.


For one-family dwellings and the individual dwelling units of two-family and multifamily dwellings, single-phase feeder conductors consisting of 2 ungrounded conductors and the neutral conductor from a 208Y/120 volt system shall be permitted to be sized in accordance with 310.15(B)(7)(1) through (3).

In this section we can use it for the same types of units, but the voltage is 208Y/120 and a reduced neutral “can not be used”.  So you will be required to pull the same size neutral under this section.    Here in South Florida this voltage is used in Multifamily buildings.



(1) For a service rated 100 through 400 amperes, the service conductors supplying the entire load associated with a one-family dwelling, or the service conductors supplying the entire load associated with an individual dwelling unit in a two-family or multifamily dwelling, shall be permitted to have an ampacity not less than 83 percent of the service rating.

(2) For a feeder rated 100 through 400 amperes, the feeder conductors supplying the entire load associated with a one-family dwelling, or the feeder conductors supplying the entire load associated with an individual dwelling unit in a two-family or multifamily dwelling, shall be permitted to have an ampacity not less than 83 percent of the feeder rating.

(3) In no case shall a feeder for an individual dwelling unit be required to have an ampacity greater than that specified in 310.15(B)(7)(1) or (2).

(4) Grounded conductors shall be permitted to be sized smaller than the ungrounded conductors, if the requirements of 220.61 and 230.42 for service conductors or the requirements of 215.2 and 220.61 for feeder conductors are met.


The table below comes from ANNEX D in the back of the 2017 CODE book.

This table was made using the 83% rule for sizing the conductors to a residential dwelling unit.

Coming in the 2020 Code Book this Table will have a home at 310.12 which will be nice to see it back in the Code book where it belongs.  The inclusion of the 83% rule confused many people and was mis-interpreted all the time.  I was often asked if it was 83% of the load calculation, 83% of the wire size and a number of other mis-understood interpretations.



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One of the most important parts of this 83% rule is that the load calculation can exceed the ampacity of the conductors chosen.

An example is a 200a load calculation comes out to 190 amperes.  We are allowed to use the 83% rule because it is a residential service or feeder.  The 200 ampere service rating is multiplied by the 83% ( 200  X 83%  =  166. amperes) which gives us 166 amperes.  We then go to Table 310.15(B)(16) and go down the 75 degree column and find the a 2/0 copper conductor has the ampacity of 175 amperes which exceeds the 166 ampere used in the 83% rule, so a 2/0 Cu. can be used for a 200 ampere service or feeder.

Hope this helps.

Till next time be safe work safe.

Jake


Continue ReadingHOW TO SIZE A RESIDENTIAL SERVICE PER SECTION 310.15(B)(7), USING THE 83% RULE

IMPROVISE

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This is what you get when you “IMPROVISE” with electrical work.

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An unhappy customer!

Till next time be safe work safe.

Jake

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250.52 Grounding Electrodes Electrodes Permitted for Grounding.

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This weeks news letter is about what we call a Uffer Ground (Concrete encased electrode) 250.52(A)(3).  It seems to be a mis-interpreted Code section, that a lot of contractors and inspectors alike do not understand.  This Uffer Ground is a type of grounding electrode and not a point to bond the steel in a building slab. We are not bonding the steel in a slab of a building, we making the steel in the slab of a building into a grounding electrode, one 20’ piece.

As stated in the Code section we are to take 20’ of rebar and run #4 cu.to it and use it as one of our required grounding electrodes, when it is available.  Yes, if it is available.  If we missed it on the pour of the slab it then becomes unavailable, so we use some other method.  If you miss it and it is called for on the plan you will need to get the plans changed to show another method. It is not required to chip into the slab and expose a piece of steel so that we can accomplish this, because how do we know it is 20’ long.

So if your slab has several separated steel electrodes (ones that are 20’ and are available) you don’t have to bond them all together to form one, we just need one. (see the highlighted section below)  Then next time you fail an inspection for not boding all the steel pads in a home, remember “YOU DON”T HAVE TO”!!!

One other note on this electrode is the informational note at the bottom of the section which states that the concrete should be in direct contact with the earth and not sitting above a piece of plastic vapor barrier.  

250.52(A)(3) Concrete-Encased Electrode. A concrete-encased electrode
shall consist of at least 6.0 m (20 ft) of either (1) or (2):
(1) One or more bare or zinc galvanized or other electrically
conductive coated steel reinforcing bars or rods of not less
than 13 mm (1⁄2 in.) in diameter, installed in one continuous
6.0 m (20 ft) length, or if in multiple pieces connected
together by the usual steel tie wires, exothermic welding,
welding, or other effective means to create a 6.0 m (20 ft)
or greater length; or
(2) Bare copper conductor not smaller than 4 AWG

Metallic components shall be encased by at east 50 mm
(2 in.) of concrete and shall be located horizontally within that
portion of a concrete foundation or footing that is in direct contact
with the earth or within vertical foundations or structural
components or members that are in direct contact with the earth.
If multiple concrete-encased electrodes are present at a building
or structure, it shall be permissible to bond only one into the
grounding electrode system.

  
Informational Note: Concrete installed with insulation, vapor
barriers, films or similar items separating the concrete from the
earth is not considered to be in “direct contact” with the earth.

Uffer Ground

Next we have a new type of connector in a meter can given to me by Howard of Stuart.

meter base

Till next time be safe work safe.

Jake


Continue Reading250.52 Grounding Electrodes Electrodes Permitted for Grounding.

Renewing your Palm Beach County License

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I have had several calls from contractors looking for Continuing Education classes.  If you have a Palm Beach County license and are renewing your PBC license send them your CEU’s from last two years (2019 and 2020) that you got for the state renewal last year.  The State of Florida does not have a renewal this year its next year 2022.  We will be back in class giving CEU classes this December.  If you renew with the State next year you are ONLY REQUIRED to get 11 hours if you have an EC or ER license, and 7 hours for all other specialty licenses for the State.  One of the problems with this new requirement is the State only wants 11 or 7 hours, but Palm beach County still wants 14 hours.  So in order to renew in PBC you will have to get extra hours not required by the State.

So starting in December we will be offering the 11 hrs. required by the State plus the other 3 required by Palm Beach County if you need them. 

Below is the list of “STATE” required hours for our trade as of July 1, 2020.

Effective July 1, 2020 a licensee must complete the following continuing education prior to renewal:

Certified Electrical Contractors (EC) = 11 hours of Continuing Education
1 hour workers’ compensation
1 hour workplace safety
1 hour business practices
1 hour Florida Laws & Rules
7 hours of Technical to include – 1 hour Florida Building Code advanced module course and 2 hours false alarm prevention for all certified electrical contractors who perform alarm work

Registered Electrical Contractors (ER) = 11 hours of Continuing Education
1 hour workers’ compensation
1 hour workplace safety
1 hour business practices
1 hour Florida Laws & Rules
7 hours of Technical to include – 1 hour Florida Building Code advanced module course

Certified and Registered Alarm Contractors = 7 hours of Continuing Education
1 hour workers’ compensation
1 hour workplace safety
1 hour business practices
1 hour Florida Laws & Rules
2 hours false alarm prevention
1 hours of Technical to include – 1 hour Florida Building Code advanced module course

Certified and Registered Specialty Contractors = 7 hours of Continuing Education
1 hour workers’ compensation
1 hour workplace safety
1 hour business practices
1 hour Florida Laws & Rules
1 hours of Technical to include – 1 hour Florida Building Code advanced module course
2 hours general credit

Confused by all this email me (jlecceamil@hotmail.com) or Text me at (561-596-7347) I will try to help you if needed.

Till next time be safe work safe.

Jake

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Needs Help

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My bosses  daughter lives in Orlando and is in need of a good electrician.  Does anyone know someone up there, she lives in Hunter’s Creek. Let me know.

Be safe.

Jake

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