Originally Posted by leeym
Is there a way to calculate how many switches or lights I can attach in series to one single circuit in my house? How does this calculation relaye to the typs of romex cabling I'm using?
The National Electric Code does not restrict the number of switches or luminaires that can be placed on any circuit.
The rule is that the wattage rating of all luminaires does not exceed the maximum wattage of the circuit.
For a 15 amp circuit, the total amount of load drawn by all luminaires cannot exceed 1800 watts.
Volts X Amps = Watts
120 Volts X 15 Amps = 1800 watts.
For a 20 amp circuit, the total amount of load drawn by all luminaires cannot exceed 2400 watts.
No limit on the amount of switches.
A switch is a device
. A device is defined by the Code as "a unit of the electrical system that is intended to carry but not utilize electrical energy."
Since switches do not (normally) consume energy, their amount is not restricted.