Common throughout a house. Widely available.
Yes. I know of no limits to how many regular receptacles (outlets) you can "piggy back" onto one GFCI receptacle. However, in commercial and industrial construction there are limits to how many receptacles can be placed on any one circuit. These limits in the United States and according to the NEC are: 10 receptacles on a 15 amp circuit and 13 receptacles on a 20 amp circuit.
It is perfectly acceptable to have (2) 120 volt 15 amp receptacles operated from a 120 volt 20 amp circuit breaker (as a general rule of thumb 11 receptacles are acceptable on a 20 amp circuit). The 15 amp rating of the receptacle is the maximum allowed amperage that should be hooked up to the receptacle at any one time. So in this case the limiting factor is the amount of current being drawn across both receptacles simultaneously should not exceed the 20 amp rating of the circuit breaker. In the United States the NEC code allows the use of a 20 amp circuit breaker to feed a branch circuit consisting of 15 amp receptacles. Generally you would not exceed 11 receptacles though as you will assume an average load of 1.5 amps per receptacle and trying to maintain about 80% max load.
The NEC does not limit the receptacles in a residents. Industrial it is limited to 180 watts each.
In the United States and according to the NEC, in commercial and industrial installations, you are limited to 10 receptacles on a 15 amp circuit. The size of the wire is not a determining factor. There is no limit to the number of receptacles on a circuit in a home and there may be local codes where you live that have stricter requirements.
NO! You are drastically in excess of electrical code requirement. A 15 amp circuit should not exceed eight total receptacles and/or lighting devices.
No. In a 20 amp circuit all wire has to be 12 AWG or larger.
A #14 copper wire rated at 15 amps is the minimum size wire for a 15 amp receptacle.
Many receptacles will. First you need to tell us if you are in north America, UK or Australia.
Replace the 30 Amp Breaker with a 15 Amp breaker.
There isn't a formula, but the general rule is that you allow for 1 amp per outlet and you load the circuit to 80% of maximum. For a 15 Amp circuit you can have a maximum of 12 outlets.
In North America the standard sizes for breakers are 15, 20, 30, and 40 amps. The 15 amp size breaker is used in general circuit wiring. The 20 amp size breaker is used for dedicated appliance receptacles, hot water tank and baseboard heating. The 30 amp size breaker is used for a clothes dryer. The 40 amp size breaker is used for the electric range.
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