Residential Service Calculator
Area =
Sm Appliance Circuits = 2
Laundry Circuits = 1
Electric Appliance Ratings
Dishwasher = 0
Range = 0
Cooktop = 0
Oven = 0
Disposal = 0
Microwave = 0
Hydromassage Bathtub = 0
Clothes Dryer = 0
Garage Door Opener = 0
Water Heater = 0
Other = 0
Other = 0
Other = 0
Other = 0
Other = 0
AC Rating =
Heating Equipment
Heat Pump = 0
HP Supplemental Heat = 0
Space Heat (3 or less) = 0
Space (4 or more) = 0
Other Heat Type = 0
Min Service Size =
m_dgl =
m_gl =
t_amp = [100.49;125.49; 150.49; 175.49; 200.49; 225.49; 250.49; 300.49; 350.49; 400.49; 450.49; 500.49; 600.49; 700.49; 800.49; 1000.49; 1200.49; 1600.49; 2000.49; 2500.49; 3000.49; 4000.49; 5000.49; 6000.49]
- ++floor++: expanded, see [https://.../t/help_functions_number|floor()]
- ++lookup++: parameters changed, see [https://.../t/help_functions_tables|lookup()]
- ++max++: expanded, see [https://.../t/help_functions_statistics|max()]
Help
Calculates the minimum size service required for a single family dwelling, using the optional method of calculating service loads, as permitted by Part IV of Article 220 in the 2014 National Electrical Code.
Rows
- Area: Area of the home. Do not include area of garage(s), open porches, or unused/unfinished spaces that are not adaptable for future use.
- Sm Appliance Circuits: Number of small appliance branch circuits in the home. Small appliance branch circuits serve receptacle outlets in kitchens, dining rooms, breakfast rooms, pantries and similar areas. Section 210.11(C)(1) of the 2014 National Electrical Code requires each home to be provided with at least 2 small appliance branch circuits.
- Laundry Circuits: Number of laundry branch circuits in the home. Laundry branch circuits serve receptacle outlets in laundry rooms or areas only. Section 210.11(C)(2) of the 2014 National Electrical Code requires each home to be provided with at least 1 laundry branch circuit.
Electric Appliance Ratings
In the following fields, enter the rating in watts of the individual appliances in the appropriate section. If multiple appliances of the same type are provided in the home, enter the total rating of all of the same appliances. For example: If a home has 2 garage door openers, each rated 750 watts, enter 1,500 into the section titled garage door opener. If more appliances are installed in the home than entries are allowed, enter the total of all remaining appliances into the section identified as "Other". Leave all fields blank that are not applicable to the home. Do NOT enter the ratings of heating or air-conditioning equipment in this section.
- Dishwasher:
- Range:
- Cooktop:
- Oven:
- Disposal:
- Microwave:
- Hydromassage Bathtub:
- Clothes Dryer:
- Garage Door Opener:
- Water Heater:
- Other:
- Other:
- Other:
- Other:
- Other:
- AC Rating: Total load in watts of all air-conditioning equipment in the home.
Heating Equipment
In the following fields, enter the total load in watts for the appropriate type of heating equipment in the home. Do not enter values for equipment not installed in the home.
- Heat Pump: Rating of the heat pump compressor (in watts) if a heat pump is used for the heating of the home.
- HP Supplemental Heat: Heat pump is used for the heating of the home and supplemental heat strips are installed, Total rating of the supplemental heat (in watts).
- Space Heat (3 or less): Total rating of all electric space heating (in watts) if the heaters are controlled by 3 or fewer thermostats.
- Space (4 or more): Total rating of all electric space heating (in watts) if the heaters are controlled by 4 or more thermostats.
- Other Heat Type: If other types of heating systems are installed in the home, such as geothermal heating, enter the total rating (in watts) of the electric heating system.
- Min Service Size: Minimum size service in amps needed for this residential dwelling.
Notes
The calculations are based on single phase, 120/240 volt services. All loads must be entered in watts. Appliance ratings can be found on the equipment nameplate. Some appliance ratings are provided in kilowatts (kW). To convert from kilowatts to watts, multiply the kilowatt rating of the appliance by 1,000. For example: 9.6 kilowatts is equal to 9,600 watts. Other appliance ratings may be given in amps. Use the Ohm's law calculator to convert loads given in amps to watts.
Examples
Calculate the minimum size service required for a single family dwelling unit that is 2400 square feet using NEC minimum requirements. The appliance ratings are as follows: Range (11,000), Dishwasher (1,500), Disposal (900), Microwave (1,800), Clothes Dryer (4,500), Garage Door Opener (1,600), and Water Heater (4,000).
- Area: 2,400ft²
- Sm Appliance Circuits: 2
- Laundry Circuits: 1
Electric Appliance Ratings
- Dishwasher: 1,500 watts
- Range: 11,000 watts
- Cooktop: 0 watts
- Oven: 0 watts
- Disposal: 900 watts
- Microwave: 1,800 watts
- Hydromassage Bathtub: 0 watts
- Clothes Dryer: 4,500 watts
- Garage Door Opener: 1,600 watts
- Water Heater: 4,000 watts
- Other: 0 watts
- Other: 0 watts
- Other: 0 watts
- Other: 0 watts
- Other: 0 watts
- AC Rating: 6,700 watts
Heating Equipment
- Heat Pump: 5,200 watts
- HP Supplemental Heat: 10,000 watts
- Space Heat (3 or less): 0 watts
- Space (4 or more): 0 watts
- Other Heat Type: 0 watts
The minimum size of the service for this residence is 150 amps.
Keywords
Area
Sm Appliance Circuits
Laundry Circuits
Dishwasher
Range
Cooktop
Oven
Disposal
Microwave
Hydromassage Bathtub
Clothes Dryer
Garage Door Opener
Water Heater
Other
Other
Other
Other
Other
AC Rating
Heat Pump
HP Supplemental Heat
Space Heat (3 or less)
Space (4 or more)
Other Heat Type
Min Service Size
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