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Home Electrical Service Calculation
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Summary: The home electrical service size is based upon the electrical loads and the required circuits specified by the electrical codes as shown in this example. © By: Dave Rongey |
Electrical Service Calculations Process
This electric service calculation is based on a single family home of 3000 square foot with the following electrical loads:
1- 12 kw electric range
20 kw of electric space heating (1 central elect. heating unit)
1- 5 kw electric water heater
1-central air conditioner, 9 kw
1- dishwasher, 1 kw
1- disposal, 0.9 kw
1- electric clothes dryer, 4500 watt
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| 220-3a | General Lighting, 3000 sq ft x 3 watts = 9000 | -- |
| 220-16a | 2 Small Appliance, 1500 ea= 3000 | -- |
| 220-16b | Laundry = 1500 | -- |
| Table 220-11 | Total General Lighting, Small Appl., Laundry = 13500 | -- |
| Table 220-11 | Apply Demands, 1st 3000 watts | 3000 |
| Table 220-11 | Balance(10500 watts) at 35 percent | 3675 |
| 220-18 | Dryer (minimum 5k) | 5000 |
| 220-19 | Range (from col C) | 8000 |
| 220-17 | Add Fixed Appliance x 100 percent (not more than four) | 6900 |
| 220-21 | Larger of Heat / Air Conditioning | 20000 |
| VA | Total | 46575 |
| Amps | Divide by 240 (volts) = | 194 |
| 310-15(b)6 | 200 Amp service wire: | 2/0 copper |
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