# Home Electric Panel Questions [duplicate]

I’m having a pool put in and the pool guys said they need a 20 amp breaker for the pool equipment. My outside panel says 100 amps (see picture). But my panel inside adds up well over 100 amps. Is this normal? The breakers never trip even with the dryer, AC, and other appliances running.

## This is quite normal

Because you aren't plugging a 15A space heater into every circuit with the dishwasher, microwave, dryer, A/C, water heater, and stove all running full blast, circuits have two values associated with them: an ampacity, and a rated load. The ampacity is set by the wire in the wall and the wiring devices (receptacles, light fixtures, switches) connected to said wires, and is governed by the circuit breaker in the panel, which will be selected according to the Code rules (Article 240 and Table 310.15(B)(16)) in order to protect the wire and wiring devices from overloads and shorts. The rated load, however, is set based on a series of rules provided in the National Electrical Code (Part II of Article 220, to be precise):

• General lighting and receptacles are provided for by an allowance that covers all such branch circuits (for a residence/dwelling unit, this is 3VA per square foot).
• Kitchen and laundry small appliance branch circuits add 1500VA each.
• Furthermore, there is a demand factor applied to the above loads to account for not everything in your house being on all the time. (You get to halve any of this general receptacle/lighting load that is above 10kVA, in other words.)
• Standard residential electric dryers are counted using an allowance of 5000VA. Likewise, electric ranges get an allowance based on the size of the range -- for all but the largest residential ranges, 8000VA is a safe figure, but some extreme cases may require the full complexity of the Code's procedure for this.
• Finally, other appliances on dedicated circuits get counted as nameplate loads. (In other words, they use the power figure on the appliance's label/nameplate, which will be same label where the UL/ETL/... markings are found.)