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MistressEll

06:48AM | 06/18/05
Member Since: 01/30/05
361 lifetime posts
210.52(C)(1) throught (C)(5)

Exception No. 1 to 210.52(B)(1) is meant for example a separate switched

lighting circuit for that UC lighting in which the switch controls the receptacle that feeds the lighting

i.e. transformer supplied low voltage under cab lighting. These are limited to 15 amp circuits.

as are all luminaries, and are rated as demand loads and limited to 1440 va.

Demand Load (luminare/lighting fixtures) designed at 80% (converse of 125%).

Simple math, VA = volts times Amps. To determine the "amp" portion, divide VA by Volts.

1440 divided by 120 volts equals 12 amps. 12 amps just happens to be exactly 80% of 15 amps. Hence the restriction for any combination circuit in residential wiring that includes a recepticle AND a luminaire (light fixture) to 15 amps, UNLESS OTHERWISE EXCEPTED...i.e. dedicated bathroom circuit allowing overhead "outlet" to include fan/light. This restriction has been in the codes a LONG TIME. So sorry you missed it.


MistressEll

07:03AM | 06/18/05
Member Since: 01/30/05
361 lifetime posts
The National Electrical Code (NEC) addresses current carrying capacities of both conductors and components. Unfortunately, some designers fail to recognize the limited SCCR of some lighting contactors. They may mistakenly place this equipment in a circuit with higher fault currents than the product listing allows. Electrical design safety of the lighting control system is instrumental in developing the foundation of the system before details of the control scheme are established.

Receptacles NEW 2002 NEC 406.

Luminaire. A complete lighting unit that consists of a lamp or lamps together with the parts designed to distribute the light.

Intent: “Luminaire” replaces the terms “fixture” and “lighting fixture,” which were used throughout the 1999 NEC but never defined. The Illuminating Engineering Society of North America and most manufacturers use this new term.

Art. 210 - Branch Circuits

210.7 Branch Circuit Receptacle Requirements

(A) Receptacle Requirements. Receptacle outlets must be located on branch circuits in accordance with the requirements listed in Part III of Article 210.

(B) Receptacle Requirements. Specific receptacle requirements are covered in Article 406.

Intent: Usability of the Code has become important to the Code-making panels. They believed relocating the installation requirements for receptacles and cord connectors to Art. 406 would make the Code easier to use. Art. 406 also includes the installation requirements for receptacles and cord connectors that were located in Art. 410, Part L of the 1999 Code.

210.7 Branch Circuit Receptacle Requirements

(C) Multiple Branch Circuits. Where more than one branch circuit supplies more than one receptacle on the same yoke, a means at the branch circuit panelboard must be provided to simultaneously disconnect the ungrounded (hot) circuit conductors supplying the receptacles.

Intent: The change makes it necessary for all ungrounded (hot) circuit conductors terminating on multiple receptacles (duplex) on the same yoke to be disconnected simultaneously regardless of type of occupancy. The rule prevents persons from working on energized circuits they thought were disconnected. The 1999 NEC only required the circuit disconnect to simultaneously interrupt the multiwire circuit to multiple receptacles on the same yoke if the receptacle was located in a dwelling unit.

Luminaire. A complete lighting unit that consists of a lamp or lamps together with the parts designed to distribute the light.

Intent: “Luminaire” replaces the terms “fixture” and “lighting fixture,” which were used throughout the 1999 NEC but never defined. The Illuminating Engineering Society of North America and most manufacturers use this new term.

Qualified Person. A person who has the skill and knowledge related to the construction and operation of the electrical equipment and its installation. This person has received safety training on the hazards involved with electrical systems.

Intent: The 1999 NEC used the term “Qualified Person(s)” in about 65 sections, and the revision clarifies that a qualified person must have received safety training on the hazards involved. No longer is a person considered qualified simply by being familiar with the construction and operation of the equipment and the hazards involved.

Art. 110 - Requirements for Electrical Installations

210.12 Arc-Fault Circuit-Interrupter (AFCI) Protection

(A) AFCI Definition. An AFCI protection device provides protection from an arc fault by recognizing the characteristics unique to an arcing fault and by functioning to de-energize the circuit when an arc fault is detected.

(B) Dwelling Unit Bedrooms. All branch circuits supplying 15 or 20A, single-phase 125V outlets installed in dwelling unit bedrooms must be AFCI protected by a listed device that protects the entire branch circuit.

Intent: The change extends AFCI protection to all 125V outlets in dwelling unit bedrooms, whereas the 1999 NEC only required AFCI protection for all branch circuits that supply 15A or 20A, single-phase 125V receptacle outlets in dwelling unit bedrooms. The Code defines an outlet as “a point on the wiring system at which current is taken to supply utilization equipment” [Art. 100]. This includes openings for receptacles, luminaires, or smoke detectors.

The practice of separating the lighting from the receptacle circuits in dwelling unit bedrooms will now require two AFCI circuit breakers. The 125V limitation to the requirement means AFCI protection would not be required for a 240V baseboard electric heater.

Made of Insulating Material: Sec. 410-18(b), Ex. -- new. This new exception allows you to install a luminaire (lighting fixture) with exposed conductive parts at an existing outlet where the wiring method does not provide an equipment-grounding conductor. In such cases, this rule allows you to install and use a separate equipment-grounding conductor in accordance with Sec. 250-130(c). This rule change provides a legal means for installing a luminaire (fixture) with exposed metal parts on existing branch-circuits without the existing wiring method having an equipment-grounding conductor means.

There are other restrictions in the NEC that may appear to disallow this, however, principally Sec. 210-23. For example, Sec. 210-23(a) reads as follows (pay particular attention to the second sentence):

(a) 15- and 20-Ampere Branch Circuits. A 15- or 20-ampere branch circuit shall be permitted to supply lighting units, other utilization equipment, or a combination of both. The rating of any one cord- and plug-connected utilization equipment shall not exceed 80 percent of the branch-circuit ampere rating. The total rating of utilization equipment fastened in place shall not exceed 50 percent of the branch-circuit ampere rating where lighting units, cord-and plug-connected utilization equipment not fastened in place, or both, are also supplied.

Be careful with the second sentence. It refers to the rating of any one utilization equipment. It applies to applications where there are multiple receptacles or multiple outlets. The idea is to reserve some branch-circuit capacity for the vacant half of a duplex receptacle, for example, or for other receptacles on the circuit. Then, if equipment is permanently installed, the rules reserve even more capacity (50%) for the other outlets or receptacles. The result is a logical progression from a 100% loading allowance for an individual branch circuit, to an 80% limit on any one cord- and plug-connected appliance, to not over 50% for permanent equipment.

The parent language in Sec. 210-23, which governs all subsections that follow, supports this argument:

210-23. Permissible Loads. In no case shall the load exceed the branch-circuit ampere rating. An individual branch circuit shall be permitted to supply any load for which it is rated. A branch circuit supplying two or more outlets shall supply only the loads specified according to its size in (a) through (d) below and summarized in Section 21024 and Table 210-24.

The second and third sentences of this section must be read in concert. The second sentence clearly allows, as in this case, a 20A individual branch circuit to supply a 19A microwave oven, and a 30A branch circuit to supply a 29A coffee maker. The third sentence has the effect of removing the receptacle restrictions from the individual branch circuits described here. The subsections that follow only apply where there are "two or more outlets."

This will be further clarified in the 1996 NEC. The words "or receptacles" will

Branch-circuit protection

This analysis assumes noncontinuous loading. The branch-circuit overcurrent protection must properly protect the plugs and receptacles as installed, and Sec. 210-21(b)(1) requires the branch-circuit protection to not exceed the receptacle configuration ratings in these cases. If the load were effectively continuous, the branch-circuit overcurrent protection would need to be increased to cover the additional 25 % load allowance required by Sec. 220-3(a), and that would, in turn, increase the required receptacle (and therefore, the required plug) ratings. This in turn is why the UL standard (see Par. 10.5.5 above) normally requires a 125% allowance and only permits the 100% sizing with actual continuous loading not over 80% of the branch circuit rating.

http://ecmweb.com/mag/electric_art_overcurrent_protection/index.html

Dwelling units.

As noted above, GFCI protection has been required for all 15A and 20A, 125V receptacles in the bathroom area of a dwelling unit for more than 20 yr.

GFCI protection devices are also required for all 15A and 20A, 125V receptacles located in garages and grade-level portions of unfinished or finished accessory buildings used for storage or work areas of a dwelling unit [210.8(A)(2)]. However, there are a couple of exceptions to this rule. GFCI protection is not required for receptacles that are not readily accessible, such as a ceiling-mounted receptacle for a garage door opener. Nor are they required for a receptacle on a dedicated branch circuit located and identified for a cord-and-plug-connected appliance, such as a refrigerator or freezer.What about crawl spaces and unfinished areas of the basement? Once again, all 15A and 20A, 125V receptacles installed within a dwelling unit crawl space [210.8(4)] or in each unfinished portion of a basement not intended as a habitable room but used for storage or as a work area [210.8(5)], must be GFCI-protected. However, the Code does note a few exceptions to these rules: GFCI protection is not required for receptacles that are not readily accessible or are located on a dedicated branch circuit and identified for a specific cord-and-plug-connected appliance, such as a sump pump.

Circuit breakers are designed to carry 100% of their rated current while the NEC dictates an 80% application. Why the difference?

One of the most often asked questions is, "How do I size a circuit breaker?" A commonly misunderstood fact about circuit breakers (CBs) is related to the percentage of loading permitted by the NEC and the CB design, and why the two may be different. Let's investigate both aspects.

CB design

A CB is designed and evaluated to carry 100% of its rated current for an indefinite period of time under standard test conditions. These conditions, per UL 489, Underwriters Laboratories Standard for Safety for Molded-Case Circuit Breakers and Circuit Breaker Enclosures, include mounting the CB in free air (i.e.: with no enclosure) where the ambient temperature is held at 40 [degrees] C (approximately 104 [degrees] F). Under these conditions, molded-case CBs are required not to trip at rated current.

However, a CB most frequently is applied in equipment at 80% of its rated current under NEC Sec. 384-16(c). If you understand why this requirement is in place, you'll be able to apply CBs correctly.

CB characteristic trip curves

CB characteristic trip curves document how long it takes for specific CBs to trip depending upon the level of current. Fig. 1 shows a typical curve for a thermal-magnetic CB. The curved portion at the top represents the time it takes for the CB to trip on overload. An overload condition will cause heat buildup around the current path, within the CB as well as along the power conductors. This heat, which is generated by the current flow, is actually what causes the CB to trip in this region not simply the magnitude of the current flow. This portion of the curve is said to have an inverse time characteristic, which means that the CB will trip in less time at higher levels of current flow.

Since the current path (including both the CB and the conductor) reacts to heat, the overall operating temperature of the equipment becomes a factor in sizing a CB in an enclosure.

Other factors that may affect this equipment operating temperature include:

* Size and location of the enclosure;

* More than one current carrying device housed in the same enclosure;

* Level of current each device is carrying; and

* Environmental conditions in the area of the equipment.

Consequently, simply designing a CB to hold 100% of its rated current only addresses a portion of the concern. The equipment must be able to safely sustain the heat generated by all sources without exceeding the temperature limits in the product test standard. Both of these factors are accounted for by the sizing rules imposed by the NEC.


MistressEll

07:05AM | 06/18/05
Member Since: 01/30/05
361 lifetime posts
The 1996 NEC recognized that overcurrent protective devices will be affected by heat in the system. As such, it defines the concept of continuous loads and the 80% rule to try and offset the effects of heat in the system when sizing a CB.

Continuous loads. To better understand the sizing aspects of a CB, you must first clearly understand the concept of continuous loads. In Art. 100, the NEC defines a continuous load as "a load where the maximum current is expected to continue for three hours or more." It's critical for you to understand that this is a load at its maximum current uninterrupted for at least three hours. Office lighting typically meets this qualification.

NEC sizing rules. Secs. 210-22(c), 220-3(a), 220-10(b), and 384-16(c) all relate to the sizing rules for overcurrent protective devices (OCPDs). The first three all specify the same requirement:

OCPD size = 100% of noncontinuous load + 125% of continuous load.

Sec. 384-16(c) has the same requirement, except that it's stated in terms of the loading of the OCPD. This rule states that an OCPD can be loaded to only 80% of its rating for continuous loads. Remember that 80% is the inverse of 125% (0.80 = 1 [divided by] 1.25) and, as such, the rules are indeed identical in their end requirement.

Read the rule closely; the 125% sizing of the OCPD (or 80% loading) is only applicable when continuous loads are involved. CBs and other OCPDs can be sized at 100% of their rating for noncontinuous load applications.

100%-rated devices. The NEC does recognize complete assemblies (including the OCPDs) that are listed for operation at 100% of their rating for continuous loads. This means that the equipment has undergone additional testing to verify that it can handle the additional heat rise associated with this level of operation.

A 100%-rated CB and the end use equipment have been tested to verify that the additional heat generated by the 100% continuous loading conditions is safely dissipated. Other equipment specifications also are driven by the need to dissipate the heat associated with the level of heat rise achieved during 100% rated testing. In cases where the temperature at the CB wiring terminals exceeds 50 [degrees] C during 100% rated testing, UL 489 requires the use of 90 [degrees] C insulated wire (sized at the 75 [degrees] C ampacity) with these CBs, and the CB must be marked as such by the manufacturer. UL 489 also specifies minimum enclosure size and venting requirements if needed for heat dissipation. A CB that successfully has passed these additional tests is still not listed for application at 100% of its rating for continuous loading unless it's marked as such by the manufacturer.

In summary, a CB either carries a standard rating (80%) or a 100% rating. The standard rating is subject to the NEC sizing rules we've just discussed. CBs that are 100%-rated are permitted to be loaded continuously at their full rating as long as the assembly is listed and conductors are properly connected.

CB sizing examples

The following are examples of sizing rules.

Example 1: 50A continuous load and 125A noncontinuous load.

OCPD = 100% noncontinuous load + 125% continuous load = (1.00 x 125A) + (1.25 x 50A) = 187.5A

Therefore, a 200A OCPD is needed. If a 100%-rated CB is chosen, a 175A rating (125A + 50A) is acceptable.

Example 2: 300A noncontinuous load.

A 300A device is acceptable; a 100%-rated device is not needed since the load is noncontinuous.

Example 3: 200A continuous load.

OCPD = 100% noncontinuous load + 125% continuous load = (1.00 x 0A) + (1.25 x 200A) = 250A

Therefore, a 250A device is needed. If a 100%-rated CB is selected, a 200A rating is permitted.

Example 4: 16A continuous and 30A noncontinuous.

OCPD = 100% noncontinuous load + 125% continuous load = (1.00 x 30A) + (1.25 x 16A) = 50A

Therefore, a 50A device can be selected. Although 100%-rated devices typically are not available in sizes this small, the permitted rating would still be 50A (16A + 30A = 46A; rounded up to 50A).


Billhart

12:10PM | 06/18/05
Member Since: 04/25/05
1915 lifetime posts
"These are limited to 15 amp circuits.

as are all luminaries, and are rated as demand loads and limited to 1440 va."

There is no such rule.

If so give the SPECIFICS of Article, Section, and Part, and sub-parts and which version of the code.

And copy that paragraph and put Quotes on it so that we can see what is NEC words and what are yours.

In fact what you posted under p.s. says that you can have lighting on 20 amp circuits.

"a) 15- and 20-Ampere Branch Circuits. A 15- or 20-ampere branch circuit shall be permitted to supply lighting units, other utilization equipment, or a combination of both."

And BTW, you should reference where the stuff in ps and pps came from. It is not from the link that you posted in that thread.


Roger67

03:50PM | 06/18/05
Member Since: 08/30/02
19 lifetime posts
Mistress, did it really take you from May 18 to today to put all that typing together? :D

BTW, as Bill said, there is no such rule, and no I'm not anyone else.

Roger67

tshea1

05:35PM | 06/18/05
Member Since: 05/03/05
79 lifetime posts
First the OP was asking about basement wiring.

El brought our attention to 210.52(C)(1) through (C)(5) (I’ll assume 2002 NEC since most jurisdictions are on 2002.

(C) is Counter tops, (1) is wall counter spaces, (2) island counter spaces, (3) peninsular counter spaces, (4) separate(d) spaces, (5) receptacle outlet locations. NOTHING to do with basements.

Then we are directed to 210.52 (B)(1) Exception 1. This permits switched receptacles supplied from general purpose 15-ampere branch circuits to be located in kitchens, pantries, breakfast rooms, and similar areas.

No discussion on UC luminaries.

Bottom line—There is no rule in the NEC that REQUIRES luminaries to be on 15 Amp circuits. SO SORRY YOU MISSED IT!

IF there is a rule—quote it, with references. IF you are right I will apologize.

BTW Your other 2 posts ps & pps have absolutely nothing to do with the OP.

Again I ask, “What are you qualifications/credentials?”

You can check mine in my profile!


MistressEll

07:48PM | 06/18/05
Member Since: 01/30/05
361 lifetime posts
Tshea1:

quote: "BTW Your other 2 posts ps & pps have absolutely nothing to do with the OP."

It sure did, I'll quote from the OP: "I am going to be wiring me basement which is unfinished at the time. I was wondering what size of wire I should use? 12-2 or 14-2. It will be just running lights and outlets.. I have the basement broke down into 3 sections. Have enough for the extra breakers. Also, what should I put in for a breaker, 15 amp or 20 amp for all??"

everything I wrote about sizing branch circuits, wiring ratings not just gauge but rated temp, etc. had to do with OP's OP, as did my first post on this string.

I found it particularly amusing when you stated "I'll assume its 2002 since most jurisdictons are on 2002." Really! Just where did you pull that so-called fact from?


MistressEll

08:10PM | 06/18/05
Member Since: 01/30/05
361 lifetime posts
I know that previously, any COMBINATION of cord and plug connected loads WITH lighting fixtures (now referred to as "luminaires") at 120 volts, nominal, WERE restricted to 1440VA in dwelling units (old 210-6) (not 1800VA as suggested by jarrod for receptacle circuits) irregardless of whether or not it was a 15A or a 20A branch circuit. Since lighting was required to be calculated at demand 1440va/120v=12 amps made the prohibition to inclusion in a 20 amp circuit (80%*20amps=16) obvious, hence the common practice of sep lighting circuits from recps, in residential apps not otherwise specified, as the total # of recps weren't limited on a residential branch circuit were not and are not limited in a recp only circuit unless otherwise specified.

Billhart

08:36PM | 06/18/05
Member Since: 04/25/05
1915 lifetime posts
From the 99 NEC

210-6. Branch -Circuit Voltage Limitations {note the title VOLTAGE LIMITATTIONS}

(A) Occupany Limitation. In the dwelling units and guest rooms of hotels, motels, and similar occupanices, the VOLTAGE shall not exceed 120 volts, nomimal bewteen conductors that supply the terminals of the following:

(1) Light fixtures {NOTE THIS LIMITS RESIDENTIAL CIRCUITS FOR LIGHING FIXTURE TO 120 VOLTS - THIS PART HAS NOTHING TO DO WITH SIZE OF THE LIGHTING LOAD - ONLY THAT THEY HAVE TO 120 VOLT CIRCUITS}

(2) Cord and plug connected loads 1440 volt-amperes, nominal, or less or less than 1/4 hp. {THIS SECTION HAS HTAT CORD & PLUG CONNECTED LOADS OF 1440 OR LESS HAVE TO BE ON 120 VOLT CIRCUITS. THAT YOU CAN'T INSTALL A 240 CIRCUIT TO OPERATE YOUR 500 WATT EUROPEAN MIXER. BUT IF YOU CAN INSTALL A 240 CIRCUIT FOR A 1500 WATT TOASTER}.

WHICH WAS EXPLAINED TO YOU A MONTH AGO IN

http://www.bobvila.com/BBS/Project_Management_Issues/10/20/tree-page1.html

http://www.bobvila.com/BBS/Project_Management_Issues/10/25/tree-page1.html


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