Question

for residential wiring, not less than one 20-ampere lighting branch circuit should be provided for every ___ square feet of floor area.

Answer 1

For residential wiring, at least one 20-ampere lighting branch circuit should be provided for every 600 square feet. The electricity cost for a home using 80A (80% of a 100A maximum capacity) at 120V over a month would be about $103.68 at $0.15 per kWh.

Step-by-step explanation:

According to the National Electrical Code (NEC) for residential wiring, not less than one 20-ampere lighting branch circuit should be provided for every 600 square feet of floor area. In a household electrical system, the circuit breakers are usually rated from 10 to 30 amperes and are there to protect the wiring and appliances from damage caused by excessive current flow. For example, a 15-amp circuit breaker might be used for several outlets in a living room, while a 20-amp breaker could be dedicated to a kitchen appliance like a refrigerator.

Additionally, considering a 100A home operates at an 80% capacity for safety reasons, it would equate to 80 amperes or 9,600 watts at 120V. Over a month, this adds up to approximately 691.2 kilowatt-hours (kWh). At the cost of $0.15 per kWh, this amounts to an electricity cost of approximately $103.68.

It is also important to understand that making improvements in lighting efficiency, such as moving from incandescent to fluorescent lights, can significantly reduce power consumption and consequently lower electricity bills and environmental impact.

Answer 2

For residential wiring, a 20-ampere lighting branch circuit is required for every 600 square feet of floor area to ensure electrical safety and adequate coverage. A home using 80% of 100 A service consumes 9,600 watts, resulting in a monthly usage of 691.2 kWh, and at $0.15 per kWh, the monthly cost would be $103.68.

Step-by-step explanation:

For residential wiring, not less than one 20-ampere lighting branch circuit should be provided for every 600 square feet of floor area. This is to ensure that the lighting system is safely distributed throughout the residence and is capable of handling the expected electrical load. In residential settings, circuit breakers range from 10 to 30 amps and are used to protect against electrical hazards by limiting the current that can flow through the circuit. A 20-amp circuit, for instance, is used to protect heavy-use appliances like a refrigerator, indicative of the higher current these types of appliances use.

Considering household circuit protection, usually rated at 100 to 200 Amperes, a house with 100 A service operating at 80% capacity will consume 80 A. With a voltage of 120 V, this results in a power consumption of 9,600 watts (80 A x 120 V). Over a month, this usage would equate to 691.2 kilowatt-hours (9,600 W x 24 hours/day x 30 days/month / 1,000). The associated cost at $0.15 per kWh would be $103.68 (691.2 kWh x $0.15/kWh).