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**ECCODES**• A Leader in Education Apprentice Electricians and Electricians**Apprentices and Electricians**Dwelling calculation 1,000 square foot A Standard Calculation 2011 Massachusetts Electrical Code**Note: Today's presentation does not include voltage drops,**power factor, increase use of electricity, and is intended ONLY to be used as a study-aide and not to design or to be used to validate an installation.**Always consult with the local AHJ in your area for an**interpretation.**To successfully complete this program:**• The 2011 National Electrical Code book • A calculator • A pencil and scrap-paper • A yellow highlighter**Note: Calculations written in your code book are not allowed**in most examination rooms. • If you are studying for an exam. • Candidate Information Bulletin • Board Policy**Note: At any time during this program you may stop, move**forward or return to a previous slide using the arrow keys on your computer.**In today's presentation we will discuss and calculate:**• the service over-current protection device • the minimum number of branch-circuits • required branch-circuits • other laws, codes, regulations and standards**Actual Electrical loads:**• An oil fired boiler w/ a tank-less water heater • A dishwasher-1200 watt at 120-volts • A microwave-1500 watt at 120-volts • Note: All other loads are fueled by Natural Gas.**Understanding, mandatory rules, permissive rules,**informational notes and the hierarchy table regarding laws, codes, regulations and standards is important and necessary.**90.5**Mandatory- means shall or shall not Permissive- means it shall be permitted or not required.**90.5(C)**• Informational Note- for the purpose of this calculation means: • Compliance with other regulations, codes or standards. • May be enforcedby other enforcement officials.**The hierarchy of laws, codes, regulations and standards**• Laws, Codes or Regulations each use mandatory language such as shall or shall not, thus, each carrying the same weight of enforcement. • Standards use non-mandatory language using such words as should and may. • accordingly standards are typically applied subordinate to laws, codes and regulations.**Turn-key home**The last part of this presentation is a Q and A of the presentation. Click here to go to the next slide To review the Q and A section and skip this presentation CLICK here**Let’s get back**1,000sq.foot Dwelling**ECCODES**• A Leader in Education Question: What is the minimum size over-current protection device, or in this case service disconnecting means required?**ECCODES**• A Leader in Education Question: What is the branch-circuit load ?**ECCODES**• A Leader in Education Question: What are the minimum number of branch-circuits required?**ECCODES**• A Leader in Education Question: Are there any electrical provisions that are required by other laws, codes, regulations or standards?**ECCODES**• A Leader in Education To answer all of these questions, we need to apply the provisions in the MEC and in some instances the provisions of various Laws, Codes, Regulations, and Standards.**ECCODES**• A Leader in Education Section 230.79 provides: Original Question: [in the order presented] What is the minimum size over-current protection device, or in this case service disconnecting means required?**ECCODES**• A Leader in Education Article 230 Section 230.79 provides: A service disconnecting means shall have a rating not less than the calculated load using article 220, as applicable.**ECCODES**• A Leader in Education Article 230 Section 230.79 provides: A service disconnecting means shall have a rating not less than the calculated load using article 220, as applicable. Highlighted in your book**Section 230.79 provides:**Section 230.79 provides: But in no case shall the rating of such disconnecting mean be less than the following: • 15-amperes rating for one circuit • 30-amperes rating for two circuits • 100-amperes or greater for a single family dwelling. • 60-amperes or greater for all other installations**Section 230.79 provides:**Section 230.79 provides: But in no case shall the rating of such disconnecting mean be less than the following: • 15-amperes rating for one circuit • 30-amperes rating for two circuits • 100-amperes or greater for a single family dwelling. • 60-amperes or greater for all other installations Highlighted in your book**Therefore, the minimum size service disconnecting means must**have a rating of not less than 100-amperes. 230.79 provides NOTE: How did we do that ? Explained in the Q and A section.**However, a calculation in accordance with applicable**sections of article 220 must be completed to verify that the minimum requirement is not exceeded. [See 230.79] 230.79 provides**230.79 requires that we use various parts of Article 220 in**determining the minimum size service disconnect.**220.1 states this article provides requirements for**Services [Part III and IV] and Branch-circuits [Part II].**220.1 states that this article provides requirements for**Services [Part III and IV] and Branch-circuits [Part II]. Highlighted in your Book**Part III, Section 220.40**This provides the service load shall not be less than the sum of the loads on the branch-circuits. • In accordance with Part II of this Article. • Demands for the service, may be applied using part III.**Part III, Section 220.40**This provides the service load shall not be less than the sum of the loads on the branch-circuits. • In accordance with Part II of this Article. • Demands for the service, may be applied using part III. Highlighted in your book**Part II Branch-circuit Load Calculations:**220.10 provides, in part, the branch-circuit loads for dwellings must not be less that specified in 220.12 in constituting the minimum lighting load.**Part II Branch-circuit Load Calculations:**220.10 provides, in part, the branch-circuit loads for dwellings must not be less that specified in 220.12 in constituting the minimum lighting load. Highlighted in your book**1,000 Square foot**• Table 220.12 • Dwelling- 3va/square foot. • 1000 square foot dwelling X 3va/square foot = 3,000va.**Calculating the Load:**1,000 Square foot • Table 220.12 • Dwelling- 3va/square foot. • 1000 square foot dwelling X 3va/square foot = 3,000va. Highlighted in your book**Calculating the Load:**1,000 Square foot • Table 220.12 • Dwelling- 3va/square foot. • 1000 square foot dwelling X 3va/square foot = 3,000va. What is this? Highlighted in your book**Calculating the Load:**1,000 Square foot This is called the lighting load. Highlighted in your book**Calculating the Load:**1,000 Square foot • Table 220.12 • Dwelling- 3va/square foot. • 1000 square foot dwelling X 3va/square foot = 3,000va. How many circuits are needed?**Determining the Number of Branch-circuits:**1,000 Square foot 220.12 Table; 15-ampere branch-circuit rating X 120-volt = 1,800 VA 1,800 VA divided into 3va./square foot = 600 square feet. Or 2-circuits are needed.**Calculating the Load:**1,000 Square foot In Addition: 220.14(J) provides [for dwellings] the lighting loads includes all 15 or 20-ampere outlets covered in sections, 210.11(C)(3), 210.52(E) and (G) and lighting outlets in 210.70(A).**1,000 Square foot**Summary: Lighting load includes the outlets required in section 210.52(A)(1)(2)(3).**Summary:**1,000 Square foot 210.11(C)(3)- a 20-ampere branch-circuit required. [See 210.52(D)].**Summary:**1,000 Square foot 210.52(E) The 125-volt receptacle of a 15/20-ampere rating installed outside of the dwelling.**Summary:**1,000 Square foot 210.52.(G) A receptacle outlets installed in the basement.**Summary:**1,000 Square foot 210.70(A) The lighting outlets controlled by a wall-switch in habitable rooms, basement, hallways and stairways and other similar rooms or areas.**Calculating the Load:**1,000 Square foot 220.14(J) … and no additional load calculation is necessary.**Compliance:**1,000 Square foot 210.11(A) The number of branch-circuits must be sufficient for the load and in compliance with the requirements of 220.18.