The size of the sub panel is dependant on the amount of connected loads and the amperage of these loads, or the total load in amps on how many new circuits that you will require.
Yes, you can feed a 60 amp sub panel from another 60 amp sub panel as long as the total connected load does not exceed 60 amps. Make sure to properly size the wire and protect the circuits with appropriate breakers to ensure safe operation of the sub panel.
Yes, you can use a 40 amp breaker to feed a sub panel. The wire from the 40 amp breaker must be #8 or larger. If you intend to use the full 40 amps a larger conductor must be used. Conductors can only be loaded to 80% capacity in continuous load conditions. A #8 wire is rated at 45 amps x 80% = 36 amps. The suggested size would be a #6 rated at 65 amps x 80% = 52 amps.
There are two things to think about here. First of all a 200 amp breaker will not physically fit into a 100 amp panel. This is so designed because the panel buss is not designed to conduct 200 amps before the current is cut off. A 100 amp rating on the panel is the maximum amount of current that the manufacturer states, that can be handled safely. Second if the 200 amp breaker is in the main panel then everything downstream from that breaker has to be rated for 200 amp conductivity. The wire size will have to be 3/0 from the breaker to the first over current device in the sub panel which will be the sub panel's main breaker. The sub panel can not be a load center but will have to be a combination panel. I doubt that the 100 amp sub panel's main breaker lugs would be large enough to connect the 3/0 cable.
The key is that you still only have 100 Amps to work with. You could have multiple small panels if needed for convenience, but the total capacity for constant load should not exceed 80% of maximum or 80 Amps. Also make sure neutral and ground only bonded together at main panel.
Answer for USA, Canada and countries running a 60 Hz power supply service. Yes you can add these two breakers to the sub panel. You will have to keep in mind the fact that if the total loading of the two breakers exceeds 30 amps the 30 amp sub panel breaker will trip. If you use the 20 amp and the 15 amp loads individually then you will be under the 30 amp feeder sub panel breaker and good to go. With feeders of 3 conductor #8 the 30 amp breaker can be increased to 40 amp. If there are large motor loads involved this answer will change as starting current has to be calculated into the equation. View discussion page for additional information.SAFETY ADVICE Before you do any work yourself,on electrical circuits, equipment or appliances,always use a test meter to ensure the circuit is, in fact, de-energizedIF YOU ARE NOT REALLY SURE YOU CAN DO THIS JOBSAFELY AND COMPETENTLYREFER THIS WORK TO QUALIFIED PROFESSIONALS.
The maximum amperage capacity of a 40 amp sub panel is 40 amps.
The maximum amperage capacity of the main breaker in a 100 amp sub panel with a main breaker is 100 amps.
The maximum amperage capacity of the 400 amps main panel in this electrical system is 400 amps.
The available sub panel sizes for residential electrical installations typically range from 60 amps to 200 amps.
The maximum amperage capacity of a 30 amp panel is 30 amps.
The maximum current rating for the circuit breaker in this electrical panel is 60 amps.
The maximum amperage capacity of a 50 amp breaker panel is 50 amps.
The maximum current capacity of a 100 amp service panel is 100 amps.
The maximum amperage capacity of a 100 amp panel with a main breaker is 100 amps.
The maximum amperage capacity of a 125 amp panel with a main breaker is 125 amps.
Yes, you can feed a 60 amp sub panel from another 60 amp sub panel as long as the total connected load does not exceed 60 amps. Make sure to properly size the wire and protect the circuits with appropriate breakers to ensure safe operation of the sub panel.
The recommended amperage for a sub panel in a detached garage with a 60 amp capacity is typically 60 amps.