My understanding is that if I'm needing 20 amps on a circuit, then I will need a 20 amp breaker at the subpanel, because a 15 amp breaker would trip. And a circuit protected by a 20 amp breaker would require #12AWG or larger, because 20 amps would overheat anything smaller. Is this correct?
02-01-11: Iabirder
More than likely your ARC power amp/s requires it to be connected to a 20 amp branch circuit. Not because it draws anywhere near 2400 va (20 amps x 120V = 2400 va), but rather because of the amount of inrush current the amp draws when it is first turned on. Read the owners manual for the Amp.
So why use 20 amp branch circuits for other equipment instead of 15 amp? 15 amp would be more than enough. If VD, (voltage drop), is an issue #12 or #10 wire could be used and terminated a on 15 amp breaker. The breaker determines the size of the branch circuit.
First a little back ground info. In most cases, if not all today, the guts inside a good quality 15 amp receptacle are the same as a 20 amp receptacle. The only difference is the face plate. A 15 amp recept will only accept a 15 amp male plug. It's a safety thing... Most 15 amp branch circuits use #14 awg wire, bare minimum per NEC, which is rated for 15 amps. NEMA /UL /CSA requires manufactures that use a cord and plug for an appliance/equipment cannot exceed 12 amps FLA continuous load if a 15 amp plug is used.
Per NEC code 2 or more 15 amp receptacles can be installed on a 20 amp branch circuit. ( a duplex is two recepts.)
Per NEC code a 20 amp receptacle can only be installed on a 20 amp branch circuit.
So if you want to install Oyaide R1 recepts, per NEC code, the branch circuit must be a 20 amp.... Per code it cannot be installed on a 15 amp branch circuit.
If a manufacture builds a piece of equipment with a cord and plug that draws more than 12 amps continuous FLA then he must use a NEMA 5-20P plug. A 20 amp plug will not plug into a 15 amp recept. The max allowable continuous FLA for a 5-20P plug is 16 amps, 1920 va.
If I have 80 amps worth of breakers on the subpanel, would I need to have at least an 80 amp breaker protecting the feeder on the main panel? And then the feeder size would be based on whatever wire can handle 80 amps? Can I have an even larger breaker on the main panel as long as I increase the size of my feeder appropriately?
You could have 200 amps worth of breakers in a panel. The main breaker a head of the branch circuit breakers is the gate keeper.... If the main breaker has a handle rating of 60 amps any continuous load of 60 amps and over will/should trip the breaker open. Technically, per NEC, the max continuous load placed on the breaker should not exceed 80%. Same for a branch circuit breaker, 80%.
In a residential environment most convenience outlet branch circuits have very little load if any on them. In a bedroom maybe a clock radio, table lamps, TV.... A 15 amp branch circuit with maybe an amp or two of load at any given time. Family room, living room, den, 15 amp branch circuit/s with hardly any load. Several 15 amp branch circuits breakers in the panel but hardly any load at any given time of the day.
Night time add a few lights.
20 amp branch circuits? Kitchen has a few required by NEC.
Microwave
dish washer
refrigerator
garbage disposal
GFI recepts above the counter tops for what ever....
Most of the time during the day they just sit idle. But when needed the branch circuit must be able to handle the load placed upon it.
Laundry room.
20 amp branch circuit for the washer
30 amp 240V branch circuit for the cloths dryer.
The list goes on and on. Lots of branch circuits and breakers. At any given time of the day hardly any load if any.
I believe you were talking about installing 4 new dedicated circuits for your audio/video equipment. Other than the inrush current of the ARC power amp/s a 15 amp circuit would more than likely handle all the connected load. More than likely a 20 amp branch circuit would handle the inrush current of the ARC amp/s plus the rest of the equipment.
So why do you want 4 dedicated circuits? Why do some guys have 10?
Here is just one post on the subject. There are many out there...
http://www.audioasylum.com/audio/tweaks/messages/16/167770.html
