If you mean can you put a single 20 amp breaker in an electric panel, the answer is yes. An electric panel is typically made to handle more breakers with values that add up to more than the rating of the panel on the supposition that you will never draw full load on all breakers. If you do the main breaker would trip. In your case you are under utilizing the panel, but this is not a problem.
A 100 amp service will supply your electrical current needs UP TO 100 amps.When doing load calculations on a 100 amp panel it can only be loaded up to 80 amps.
180 amps. Assuming the panel will be loaded only 80%.
Yes you can, but it is all about distribution of the load. You still have a maximum limiting current of 150 Amps. So if you did use 100 amps on the sub-panel that would only leave 50 amps on the main. Since power usage is usually not constant and varies by day and situation, you just need to make sure the load is distributed so you don't start tripping breakers.
The only time the panel will be overloaded is if every circuit breaker was loaded to maximum capacity. When these panels are designed, the main breaker protects the two bus bars that are only rated to carry a certain amount of amperage. On a 100 amp panel these bars are rated at 100 amps. Some electrical panels are de rate by the manufacturer to 80% total load. As you can see by the breaker count 8 20 amp breakers would be a load of 160 amps. This is more that the bus bars are rated at, so the main breaker will trip. A 100 amp panel's capacity for breakers is based on the probability that not all circuits will be fully loaded at once. On an average house load, on a 100 amp panel, the load could be 50 to 60 amps at any one time during the day. Of course at night this total would be much lower.
You can but your still only going to get 100 amps total between the two panels. Just because it is a 100 amps sub panel does not mean you have to feed it with 100 amps. Figure out how many amps you'll need at the sub and you may only need to feed it with 50 or 60 amps.
The rating of a panel dictates the maximum current of the panel and is protected by a breaker of that rating. If you had 200 amp service to your house and only had a 100 amp panel then you could only draw 100 amps before the breaker tripped.
You can as long as you don't assume that this gives you another 200 Amps to use. Your overall amperage will still be only 200 Amps. You can supply the sub-panel with a smaller breaker than 200 Amps.
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.
The load that is connected to the circuit is what draws the power of the electrical circuit.
If you are contemplating an electrical upgrade the 70 to 100 jump is not justified. Presuming that you are going to get a qualified electrical contractor to do the installation along with the proper permits, go to a 200 amp panel. Your labour costs are going to be the same no matter what size panel you get installed. The only difference in costs will be the materials. Go for a 200 amp 42 circuit distribution panel. It will increase your resale value of the house should you decide to sell in the future.
# 14 wire is rated for 15 amps. If the load is going to be continuous the wire can only be loaded to 80% so you would have to use a # 12 rated at 20 amps. 20 x 80% = 16 amps.
I = W/E. Current is equal to Watts divided by Volts. 1500/120 = 13 amps. A #14 is rated at 15 amps. A conductor can only be loaded to 80% for a continuous load so 80% of 15 equals 12 amps. Too small for the 1500 watt load. A #12 conductor is rated at 20 amps times 80% equals 16 amps for a continuous load. To answer your question, no, a #16 conductor will not handle a 1500 watt load.